Principles of asymmetric synthesis

CERN Document Server

Gawley, Robert E; Aube, Jeffrey

2012-01-01

The world is chiral. Most of the molecules in it are chiral, and asymmetric synthesis is an important means by which enantiopure chiral molecules may be obtained for study and sale. Using examples from the literature of asymmetric synthesis, this book presents a detailed analysis of the factors that govern stereoselectivity in organic reactions. After an explanation of the basic physical-organic principles governing stereoselective reactions, the authors provide a detailed, annotated glossary of stereochemical terms. A chapter on "Practical Aspects of Asymmetric Synthesis" provides a critical overview of the most common methods for the preparation of enantiomerically pure compounds, techniques for analysis of stereoisomers using chromatographic, spectroscopic, and chiroptical methods. The authors then present an overview of the most important methods in contemporary asymmetric synthesis organized by reaction type. Thus, there are four chapters on carbon-carbon bond forming reactions, one chapter on reductions...

The synthesis of [14C] C I pigment violet 19

International Nuclear Information System (INIS)

Filer, C.N.; Kelly, T.P.

1990-01-01

For the custom synthesis of radiolabeled compounds in the authors laboratory, aside from spectroscopic examination, their identity and radiochemical purity is routinely corroborated by demonstration of cochromatography with an authentic cold standard. In the synthesis of [ 14 C] red pigment 1 for the Cosmetic Toiletry and Fragrance Association, its insolubility precluded this. The preparation as well as characterization of 1 is described

Simple and Efficient One-Pot Synthesis, Spectroscopic Characterization and Crystal Structure of Methyl 5-(4-Chlorobenzoyloxy-1-phenyl-1H-pyrazole-3-carboxylate

Directory of Open Access Journals (Sweden)

Imtiaz Khan

2012-07-01

Full Text Available A facile one-pot synthesis of methyl 5-(4-chlorobenzoyloxy-1-phenyl-1H-pyrazole-3-carboxylate (4 is described. The title compound was efficiently synthesized by the reaction of phenyl hydrazine, dimethyl acetylenedicarboxylate and 4-chlorobenzoyl chloride in dichloromethane under reflux in good yield. The structure of the target compound was deduced by modern spectroscopic and analytical techniques and unequivocally confirmed by a single crystal X-ray diffraction analysis. The crystal of the title compound belongs to orthorhombic system, space group P 21 21 21 with cell parameters a = 6.6491(3 Å, b = 7.9627(6 Å, c = 30.621(5 Å, α = β = γ = 90° and Z = 4. The crystal packing of the compound (4 is stabilized by an offset π-stacking between the planar benzoyl-substituted diazole moieties.

Radiation Synthesis of Functional Nanoparticles for Imaging, Sensing and Drug Delivery Applications

International Nuclear Information System (INIS)

Grasselli, M.; Soto Espinoza, S.; Risso, V.; Pawlak, E.; Smolko, E.E.

2010-01-01

In the present report we describe nanoparticle synthesis by ionizing radiation from globular proteins and methacrylate monomers. Dynamic light scattering and other spectroscopic methods were performed to characterize this new material

Radiation Synthesis of Functional Nanoparticles for Imaging, Sensing and Drug Delivery Applications

Energy Technology Data Exchange (ETDEWEB)

Grasselli, M.; Soto Espinoza, S.; Risso, V.; Pawlak, E.; Smolko, E.E., E-mail: mgrasse@unq.edu.ar, E-mail: mariano.grasselli@gmail.com [Quesada 2422, piso 11, dpto. C, C1429 Buenos Aires (Argentina)

2010-07-01

In the present report we describe nanoparticle synthesis by ionizing radiation from globular proteins and methacrylate monomers. Dynamic light scattering and other spectroscopic methods were performed to characterize this new material.

solvent-free synthesis of azomethines, spectral correlations

African Journals Online (AJOL)

B. S. Chandravanshi

attention of organic and medicinal chemists [2, 3]. ... Spectroscopic data is very useful for studying the ground state equilibrium of ... determines the structure of unsaturated systems, such as E- or Z, s-cis and .... The IR and NMR spectra of selective ... The proposed mechanism for the synthesis of E- imines in presence of ...

An Efficient Catalyst for the Synthesis of Schiff Bases

International Nuclear Information System (INIS)

Fareed, G.; Afza, N.; Kalhoro, M.A.

2013-01-01

An efficient high yielding synthesis of Schiff bases (1-17) is derived from condensation of 2-fluorenamine and 4-amino phenol with a variety of aldehydes catalyzed by dodecatungstosilicic acid P/sub 2/O/sub 5/ under solvent free conditions at room temperature. The catayst is found to be more efficient in terms of ease of reaction workup and high yields. This methodology contributes to an energy efficient, facile and environamental friendly synthesis for the preparation of Schiff bases. The structures of afforded Schiff bases were characterized by spectroscopic data and elemental analysis. (author)

Synthesis and spectroscopic study of high quality alloy Cdx S ...

Indian Academy of Sciences (India)

Wintec

In the present study, we report the synthesis of high quality CdxZn1–xS nanocrystals alloy at. 150°C with .... (XRD) using a Siemens model D 500, powder X-ray ... decays were analysed using IBH DAS6 software. 3. ... This alloying process is.

Synthesis and antimicrobial evaluation of the new Isoxazole and Pyrazole derivatives

International Nuclear Information System (INIS)

Goda, F.E.; Maarouf, A.R.; El-Bendary, E.R.

2003-01-01

A series of 3-methyl-4-substituted (phenylazo) isoxazolin-5-ones(5a,b),pyrazolin-5-ones (6a-d)and pyrazolidin-3,5-diones(10a-c) have been synthesized and evaluated for their antimicrobial activities.The detailed synthesis , spectroscopic and biogical data are reported. (author)

The Synthesis and Luminescence-spectroscopic Properties of Fluorescent Condensation Polymers

Science.gov (United States)

Barashkov, Nikolai N.

1985-07-01

The results of studies on the synthesis of polycondensation phosphorus-containing aliphatic and aromatic polymers as well as the products of polymer-analogue transformations with phosphorus-groups in the side chain are examined. The light absorption and luminescent properties of the polymers obtained and of model compounds having an analogous structure are discussed. The bibliography includes 108 references.

Ethyl 2,6-Dimethoxybenzoate: Synthesis, Spectroscopic and X-ray Crystallographic Analysis

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Jonathan M. White

2012-05-01

Full Text Available The acid catalyzed esterification of 2,6-dimethoxybenzoic acid (1 in the presence of absolute ethanol afforded ethyl 2, 6-dimethoxybenzoate (2. The structure of the resulting compound was supported by spectroscopic data and unambiguously confirmed by single crystal X-ray diffraction studies. The title compound crystallized in the triclinic space group P ī with unit cell parameters a = 8.5518(3 Å, b = 10.8826(8 Å, c = 11.9939(6 Å, α = 101.273(5°, β = 98.287(3°, γ = 94.092(4°, V = 1077.54(10 Å3, Z = 4, Dc = 1.296 Mg/m3, F(000 = 448 and μ = 0.098 mm−1. Compound (2 crystallizes with two molecules in the asymmetric unit with similar conformations.

Shell model and spectroscopic factors

International Nuclear Information System (INIS)

Poves, P.

2007-01-01

In these lectures, I introduce the notion of spectroscopic factor in the shell model context. A brief review is given of the present status of the large scale applications of the Interacting Shell Model. The spectroscopic factors and the spectroscopic strength are discussed for nuclei in the vicinity of magic closures and for deformed nuclei. (author)

Synthesis of hydrogels of alginate for system controlled release of progesterone

International Nuclear Information System (INIS)

Abreu, Marlon de F.; Rodriguez, Ruben J.S.; Silva, Ester C.C. da; Barreto, Gabriela N.S.

2015-01-01

The chemical modifications of natural polymers like alginate, has allowed the development of new formulations for controlled release systems. In this work we report the synthesis of a derivative of the amidic alginate with alkyl chain. The polymer was characterized by spectroscopic techniques: Nuclear Magnetic Resonance and Fourier Transform Infrared. (author)

Spectroscopic studies of 2-thenoyltrifluoro acetonate of uranyl salts doped with europium

International Nuclear Information System (INIS)

Nakagawa, F.T.; Luiz, J.E.M. de Sa; Felinto, M.C.F.C.; Brito, H.F.; Teotonio, E.E.S.

2006-01-01

Uranyl compounds present a great potential as luminescence materials. Some examples of applications are: in laser technology, cathode ray tube, X-rays diagnostic. In this work it was studied the synthesis, characterization and spectroscopic properties study of uranyl 2-thenoyl trifluoroacetonate and uranyl 2- thenoyl trifluoroacetonate doped with europium. The compounds were synthesized and characterized by infrared absorption spectroscopy, thermal analysis, scanning electronic microscopy, and electronic spectroscopy of emission and excitation. The Eu 3+ ion acted as an effective luminescent probe, however the process of energy transfer from UO 2 2+ to Eu 3+ ion has not been efficient. (author)

The synthesis and chemiluminescence of a stable 1,2-dioxetane : an organic chemistry laboratory experiment

NARCIS (Netherlands)

Meijer, E.W.; Wynberg, H.

1982-01-01

An expt. for the synthesis of adamantylideneadamantane-1,2-dioxetane illustrating the concepts of the singlet O reaction and chemiluminescence, is described. All intermediates and products can be identified by undergraduate students using routine spectroscopic anal. [on SciFinder (R)

Synthesis of mesoporous silica microsphere from dual surfactant

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Venkatathri Narayanan

2008-12-01

Full Text Available A new procedure is reported to synthesis mesoporous silica micro sphere for the first time. In these method two surfactants namely Span 80 and Tween 80 were used. Small angle X ray diffraction and N2 adsorption analysis shows the synthesized material has mesoporous property. The material has spherical morphology with 1-10 µm particle size. Beside the material found to have microcapsule property as observed from the Transmission electron microscopy. The Fourier transform Infrared spectroscopic analysis reveals that the materials are similar to other mesoporous materials. We also encapsulated an UV-absorber Ibuprofen inside the microcapsule, by mixing it before the synthesis. This shows a possibility of the materials in cosmetic applications.

Synthesis of unstable cyclic peroxides for chemiluminescence studies

Energy Technology Data Exchange (ETDEWEB)

Bartoloni, Fernando H.; Oliveira, Marcelo A. de; Augusto, Felipe A.; Ciscato, Luiz Francisco M.L.; Bastos, Erick L.; Baader, Wilhelm J., E-mail: wjbaader@iq.usp.br [Universidade de Sao Paulo (USP), SP (Brazil). Inst. de Quimica. Dept. de Quimica Fundamental

2012-11-15

Cyclic four-membered ring peroxides are important high-energy intermediates in a variety of chemi and bioluminescence transformations. Specifically, a-peroxy lactones (1,2-dioxetanones) have been considered as model systems for efficient firefly bioluminescence. However, the preparation of such highly unstable compounds is extremely difficult and, therefore, only few research groups have been able to study the properties of these substances. In this study, the synthesis, purification and characterization of three 1,2-dioxetanones are reported and a detailed procedure for the known synthesis of diphenoyl peroxide, another important model compound for the chemical generation of electronically excited states, is provided. For most of these peroxides, the complete spectroscopic characterization is reported here for the first time. (author)

Design, Green Synthesis, and Anti-Inflammatory Activity of Schiff Base of 1,3,4-oxadiazole Analogues

Czech Academy of Sciences Publication Activity Database

Sahoo, B. M.; Dinda, S. C.; Kumar, B. V. V. R.; Panda, J.; Brahmkshatriya, Pathik

2014-01-01

Roč. 11, č. 1 (2014), s. 82-89 ISSN 1570-1808 Institutional support: RVO:61388963 Keywords : anti-inflammatory activity * design * green synthesis * oxadiazole * schiff base * spectroscopic studies Subject RIV: CC - Organic Chemistry Impact factor: 0.770, year: 2014

Trispyrazolylborate Complexes: An Advanced Synthesis Experiment Using Paramagnetic NMR, Variable-Temperature NMR, and EPR Spectroscopies

Science.gov (United States)

Abell, Timothy N.; McCarrick, Robert M.; Bretz, Stacey Lowery; Tierney, David L.

2017-01-01

A structured inquiry experiment for inorganic synthesis has been developed to introduce undergraduate students to advanced spectroscopic techniques including paramagnetic nuclear magnetic resonance and electron paramagnetic resonance. Students synthesize multiple complexes with unknown first row transition metals and identify the unknown metals by…

Synthesis and In Vitro Evaluation of C-methylcalix[4]resorcinaryl octacinnamate as the Sunscreen

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Budiana I Gusti M. Ngurah

2017-04-01

Full Text Available Synthesis and in vitro test of C-methylcalix[4]resorcinaryl octacinnamate as the sunscreen has been conducted. The C-methylcalix[4]resorcinaryl octacinnamate was synthesized in 2 steps. They were synthesis of C-methylcalix[4]resorcinarene via acid catalyzed condensation of resorcinol and acetaldehyde, followed by estherification using cinnamoyl chloride and pyridine catalyst. The characterization of the target molecule was performed by infra red spectrophotometer, proton-NMR, carbon-NMR and mass spectromether. The sunscreen activity test was conducted by spectroscopic method and MTT-assay. Spectroscopic analysis (UV showed that the target molecule absorbed the dangerous ultraviolet radiation between 280 and 320 nm (UV B wave length with the maximum absorption at 290 nm (ε = 31.535 M-1 cm-1. The MTT-assay indicated that the IC50 of C-methylcalix[4]resorcinaryl octacinnamate is 12.006 ppm. The sunscreen activity of C-methylcalix[4]resorcinaryl octacinnamate is stronger than commercial sunscreen Intersun (IC50 = 18.235 ppm.

Rhodium (II) cycle alkanecarboxylate: synthesis, spectroscopic and thermo analytic studies and evaluation of the antitumor potential; Cicloalcanocarboxilatos de rodio(II). Sintese, estudos espectroscopicos, termoanaliticos e avaliacao do potencial antitumor

Energy Technology Data Exchange (ETDEWEB)

Souza, Aparecido Ribeiro de

1995-07-01

Four new rhodium(II) carboxylates (cyclopropane, cyclobutane, cyclopentane, and cyclohexanecarboxylate), and other already known rhodium (II) carboxylates (acetate, propionate, butyrate, metoxyacetate, dichloroacetate, and trifluoroacetate), have been prepared for study in this work. The compounds were characterized by elementary and thermogravimetric analysis, magnetic susceptibility, and electronic, Raman, and infrared spectroscopy. The reaction of Rh CL{sub 3}.aq with the sodium carboxylates was studied aiming to improve the understanding of the redox process involved. Spectroscopy studies (Raman and electronic) were made to examine the transition involved in the Rh-Rh and Rh-O bonds. The results have shown a direct relation between the force of the carboxylic acid and the Rh-O force, but show a inverse relation with the Rh-Rh bond force. Thermal analysis studies were undertaken and the obtained date show a resemblance of the TG/DTG curves with that found in literature. In the other hand, the DSC curves show a different results: in open crucible, the peaks associated with the cage breakdown are exothermic and, in closed crucible this peaks are endothermic. The thermodecomposition products were analyzed. The evolved gases were identified by GC?MS and {sup 1}H and {sup 13} C NMR spectra. The residues were analyzed by X-ray diffraction. Antitumor activity of rhodium cyclopropanecarboxylate was evaluated in vitro (cell cultures K562 and Ehrlich) and in vivo (Balb-c mice with ascite Ehrlich tumor), indicating an increased life span (87.5%) of the treated animals. (author)

Spectroscopic classification of transients

DEFF Research Database (Denmark)

Stritzinger, M. D.; Fraser, M.; Hummelmose, N. N.

2017-01-01

We report the spectroscopic classification of several transients based on observations taken with the Nordic Optical Telescope (NOT) equipped with ALFOSC, over the nights 23-25 August 2017.......We report the spectroscopic classification of several transients based on observations taken with the Nordic Optical Telescope (NOT) equipped with ALFOSC, over the nights 23-25 August 2017....

Synthesis of Zinc Diethyldithiocarbamate (ZDEC) and Structure Characterization using Decoupling 1H NMR

International Nuclear Information System (INIS)

Sujarit, Jenjira; Phutdhawong, Weerachai

2003-10-01

A synthesis of zinc diethyldithiocarbamate (ZDEC) has been studied. The optimization mole ratio of the synthetic process was 2: 2: 2: 1 of diethylamine, carbondisulfide, sodium hydroxide, and zinc chloride. Characterization was carried out mainly by analyzing its spectroscopic properties especially decoupling 1 H NMR technique. ZDEC was obtained in 48.5% yield

Synthesis and IR spectroscopic investigation of solvated complexes of dioxomolybdenum (6) with salicylal-S-methyl isothiosemicarbazone

International Nuclear Information System (INIS)

Abramenko, V.L.; Sergienko, V.S.

1996-01-01

The complex of MoO 2 L (H 2 L-S-methylizothiosemicarbazone of salicyl aldehyde) and its seven solvated derivatives MoO 2 LxSolv, have been synthesized, their IR spectroscopic study being conducted. The conclusions on the structure of the complexes studied are confirmed by ata of x-ray diffraction analysis. Refs. 4, tabs. 1

Research progress in the electrochemical synthesis of ferrate(VI)

International Nuclear Information System (INIS)

Macova, Zuzana; Bouzek, Karel; Hives, Jan; Sharma, Virender K.; Terryn, Raymond J.; Baum, J. Clayton

2009-01-01

There is renewed interest in the +6 oxidation state of iron, ferrate (VI) (Fe VI O 4 2- ), because of its potential as a benign oxidant for organic synthesis, as a chemical in developing cleaner ('greener') technology for remediation processes, and as an alternative for environment-friendly battery cathodes. This interest has led many researchers to focus their attention on the synthesis of ferrate(VI). Of the three synthesis methods, electrochemical, wet chemical and thermal, electrochemical synthesis has received the most attention due to its ease and the high purity of the product. Moreover, electrochemical processes use an electron as a so-called clean chemical, thus avoiding the use of any harmful chemicals to oxidize iron to the +6 oxidation state. This paper reviews the development of electrochemical methods to synthesize ferrate(VI). The approaches chosen by different laboratories to overcome some of the difficulties associated with the electrochemical synthesis of ferrate(VI) are summarized. Special attention is paid to parameters such as temperature, anolyte, and anode material composition. Spectroscopic work to understand the mechanism of ferrate(VI) synthesis is included. Recent advances in two new approaches, the use of an inert electrode and molten hydroxide salts, in the synthesis of ferrate(VI) are also reviewed. Progress made in the commercialization of ferrate(VI) continuous production is briefly discussed as well

Mass Spectrometry in Organic Synthesis: Claisen-Schmidt Base-Catalyzed Condensation and Hammett Correlation of Substituent Effects

Science.gov (United States)

Bain, Ryan M.; Pulliam, Christopher J.; Yan, Xin; Moore, Kassandra F.; Mu¨ller, Thomas; Cooks, R. Graham

2014-01-01

Undergraduate laboratories generally teach an understanding of chemical reactivity using bulk or semimicroscale experiments with product isolation and subsequent chemical and spectroscopic analysis. In this study students were exposed to mass spectrometry as a means of chemical synthesis as well as analysis. The ionization method used, paper…

Quaternary Alkylammonium Conjugates of Steroids: Synthesis, Molecular Structure, and Biological Studies

Directory of Open Access Journals (Sweden)

Bogumił Brycki

2015-11-01

Full Text Available The methods of synthesis as well as physical, spectroscopic (1H-NMR, 13C-NMR, and FT-IR, ESI-MS, and biological properties of quaternary and dimeric quaternary alkylammonium conjugates of steroids are presented. The results were contrasted with theoretical calculations (PM5 methods and potential pharmacological properties (PASS. Alkylammonium sterols exhibit a broad spectrum of antimicrobial activity comparable to squalamine.

Synthesis, structure, spectroscopic investigations, and computational studies of optically pure β-ketoamide

International Nuclear Information System (INIS)

Mtat, D.; Touati, R.; Guerfel, T.; Walha, K.; Ben Hassine, B.

2016-01-01

Chemical preparation, X-ray single crystal diffraction, IR and NMR spectroscopic investigations of a novel nonlinear optical organic compound (C 17 H 22 NO 2 Cl) are described. The compound crystallizes in the orthorhombic system with the non-centrosymmetric sp. gr. P2 1 2 1 2 1 . In the crystal structure, molecules are interconnected by N–H…O hydrogen bonds forming infinite chains along a axis. The Hirshfeld surface and associated fingerprint plots of the compound are presented to explore the nature of intermolecular interactions and their relative contributions in building the solid-state architecture. The molecular HOMO–LUMO compositions and their respective energy gaps are also drawn to explain the activity of the compound. The first hyperpolarizability β tot of the title compound is determined using DFT calculations. The optical properties are also investigated by UV–Vis absorption spectrum.

An efficient synthesis and spectroscopic characterization of Schiff bases containing 9,10-anthracenedione moiety

Directory of Open Access Journals (Sweden)

Fareed Ghulam

2013-01-01

Full Text Available A new method has been developed for the synthesis of novel Schiff bases containg anthraquinone moiety using dodeca-Tungstosilicic acid/P2O5 under solvent free conditions at room temperature. The reaction was completed in 1-3 minutes with excellent yields. This method was found to be more efficient, easy and hazardous free for the synthesis of azomethines. The development of these type of methadologies in synthetic chemistry may contribute to green chemistry. The structures of synthesized novel Schiff bases was elucidated using 1H-NMR, 13C-NMR, LCMS, FTIR and CHN analysis.

A subspace approach to high-resolution spectroscopic imaging.

Science.gov (United States)

Lam, Fan; Liang, Zhi-Pei

2014-04-01

To accelerate spectroscopic imaging using sparse sampling of (k,t)-space and subspace (or low-rank) modeling to enable high-resolution metabolic imaging with good signal-to-noise ratio. The proposed method, called SPectroscopic Imaging by exploiting spatiospectral CorrElation, exploits a unique property known as partial separability of spectroscopic signals. This property indicates that high-dimensional spectroscopic signals reside in a very low-dimensional subspace and enables special data acquisition and image reconstruction strategies to be used to obtain high-resolution spatiospectral distributions with good signal-to-noise ratio. More specifically, a hybrid chemical shift imaging/echo-planar spectroscopic imaging pulse sequence is proposed for sparse sampling of (k,t)-space, and a low-rank model-based algorithm is proposed for subspace estimation and image reconstruction from sparse data with the capability to incorporate prior information and field inhomogeneity correction. The performance of the proposed method has been evaluated using both computer simulations and phantom studies, which produced very encouraging results. For two-dimensional spectroscopic imaging experiments on a metabolite phantom, a factor of 10 acceleration was achieved with a minimal loss in signal-to-noise ratio compared to the long chemical shift imaging experiments and with a significant gain in signal-to-noise ratio compared to the accelerated echo-planar spectroscopic imaging experiments. The proposed method, SPectroscopic Imaging by exploiting spatiospectral CorrElation, is able to significantly accelerate spectroscopic imaging experiments, making high-resolution metabolic imaging possible. Copyright © 2014 Wiley Periodicals, Inc.

FACILE SYNTHESIS OF 1-NAPHTHOL AZO DYES WITH NANO ...

African Journals Online (AJOL)

Preferred Customer

a highly efficient and one pot synthesis of azo dyes based on 1-naphthol under ... known and were identified by comparison of their physical and spectroscopic data with those of ... δ: 16.15 (s, 1H), 8.41 (d, J = 7.6 Hz, 1 H), 8.33 (d, J = 8.8 Hz, 2H), 7.8 (d, .... 86. 81. 77. 70. 65. N2. + IO4. -. O2N. 2d. 96. 93. 90. 85. 79. 73. 69.

Modeling of alkynes: synthesis and theoretical properties

Directory of Open Access Journals (Sweden)

Renato Rosseto

2003-06-01

Full Text Available In this paper we present the synthesis and simulation of alkynes derivatives. Semiempirical calculations were carried out for the ground and first excited states, including the spectroscopic properties of the absorption and emission (fluorescence and phosphorescence spectra by INDO/S-CI and DNdM-INDO/S-CI methods with geometries fully optimized by PM3/CI. The fact that the theoretical spectra are in accord with the experimental absorption spectra gives us a new possible approach on how structure modifications could affect the non-linear optical properties of alkynes.

Synthesis, structure, spectroscopic investigations, and computational studies of optically pure β-ketoamide

Energy Technology Data Exchange (ETDEWEB)

Mtat, D.; Touati, R. [Université de Monastir, Laboratoire de Synthèse Organique Asymétrique et Catalyse Homogène (UR11ES56), Faculté des Sciences (Tunisia); Guerfel, T., E-mail: taha-guerfel@yahoo.fr [Université de Kairouan, Laboratoire d’Electrochimie, Matériaux et Environnement (Tunisia); Walha, K. [Université de Sfax, M.E.S.Lab. Faculté des Sciences de Sfax (Tunisia); Ben Hassine, B. [Université de Monastir, Laboratoire de Synthèse Organique Asymétrique et Catalyse Homogène (UR11ES56), Faculté des Sciences (Tunisia)

2016-12-15

Chemical preparation, X-ray single crystal diffraction, IR and NMR spectroscopic investigations of a novel nonlinear optical organic compound (C{sub 17}H{sub 22}NO{sub 2}Cl) are described. The compound crystallizes in the orthorhombic system with the non-centrosymmetric sp. gr. P2{sub 1}2{sub 1}2{sub 1}. In the crystal structure, molecules are interconnected by N–H…O hydrogen bonds forming infinite chains along a axis. The Hirshfeld surface and associated fingerprint plots of the compound are presented to explore the nature of intermolecular interactions and their relative contributions in building the solid-state architecture. The molecular HOMO–LUMO compositions and their respective energy gaps are also drawn to explain the activity of the compound. The first hyperpolarizability β{sub tot} of the title compound is determined using DFT calculations. The optical properties are also investigated by UV–Vis absorption spectrum.

Synthesis, spectroscopic, and molecular structure characterizations of some azo derivatives of 2-hydroxyacetophenone

Science.gov (United States)

Albayrak, Çiğdem; Gümrükçüoğlu, İsmail E.; Odabaşoğlu, Mustafa; İskeleli, Nazan Ocak; Ağar, Erbil

2009-08-01

Some novel azo compounds were prepared by the reaction of 2-hydroxyacetophenone with aniline and its substituted derivatives. The structures of synthesized azo compounds were determined by IR, UV-Vis, 1H NMR and 13C NMR spectroscopic techniques and the structures of some of these compounds were also determined by X-ray diffraction studies. Structural analysis using IR in solid state shows that the azo form is favoured in the azo compounds whereas UV-Vis analysis of the azo compounds in solution has shown that there is a azo and ionic form. The azo compounds in the basic solvents dimethylformamide (DMF) and dimethylsulfoxide (DMSO) are both azo and ionic form while these compounds in ethyl alcohol (EtOH) and chloroform (CHCl 3) are only azo form.

Photoacoustic spectroscopic studies of polycyclic aromatic hydrocarbons

Science.gov (United States)

Zaidi, Zahid H.; Kumar, Pardeep; Garg, R. K.

1999-02-01

Because of their involvement in environmental pollutants, in carcinogenic activity, plastics, pharmaceuticals, synthesis of some laser dyes and presence in interstellar space etc., Polycyclic aromatic hydrocarbons (PAHs) are important. As their structure and properties can be varied systematically, they form a beautiful class of molecules for experimental and quantum chemical investigations. These molecules are being studied for last several years by using conventional spectroscopy. In recent years, Photoacoustic (PA) spectroscopy has emerged as a new non-destructive technique with unique capability and sensitivity. The PA effect is the process of generation of acoustic waves in a sample resulting from the absorption of photons. This technique not only reveals non- radiative transitions but also provides information about forbidden singlet-triplet transitions which are not observed normally by the conventional spectroscopy. The present paper deals with the spectroscopic studies of some PAH molecules by PA spectroscopy in the region 250 - 400 nm. The CNDO/S-CI method is used to calculate the electronic transitions with the optimized geometries. A good agreement is found between the experimental and calculated results.

Total synthesis of cytochrome b562 by native chemical ligation using a removable auxiliary

Science.gov (United States)

Low, Donald W.; Hill, Michael G.; Carrasco, Michael R.; Kent, Stephen B. H.; Botti, Paolo

2001-01-01

We have completed the total chemical synthesis of cytochrome b562 and an axial ligand analogue, [SeMet7]cyt b562, by thioester-mediated chemical ligation of unprotected peptide segments. A novel auxiliary-mediated native chemical ligation that enables peptide ligation to be applied to protein sequences lacking cysteine was used. A cleavable thiol-containing auxiliary group, 1-phenyl-2-mercaptoethyl, was added to the α-amino group of one peptide segment to facilitate amide bond-forming ligation. The amine-linked 1-phenyl-2-mercaptoethyl auxiliary was stable to anhydrous hydrogen fluoride used to cleave and deprotect peptides after solid-phase peptide synthesis. Following native chemical ligation with a thioester-containing segment, the auxiliary group was cleanly removed from the newly formed amide bond by treatment with anhydrous hydrogen fluoride, yielding a full-length unmodified polypeptide product. The resulting polypeptide was reconstituted with heme and folded to form the functional protein molecule. Synthetic wild-type cyt b562 exhibited spectroscopic and electrochemical properties identical to the recombinant protein, whereas the engineered [SeMet7]cyt b562 analogue protein was spectroscopically and functionally distinct, with a reduction potential shifted by ≈45 mV. The use of the 1-phenyl-2-mercaptoethyl removable auxiliary reported here will greatly expand the applicability of total protein synthesis by native chemical ligation of unprotected peptide segments. PMID:11390992

Isolation, structure, and synthesis of viridic acid, a new tetrapeptide mycotoxin of Penicillium viridicatum Westling

International Nuclear Information System (INIS)

Holzapfel, C.W.; Koekemoer, J.M.; Van Dyk, M.S.

1986-01-01

The isolation of a new toxic metabolite, viridic acid, from Penicillium viridicatum Westling is described. The chemical and spectroscopic properties of the compound are interpreted in terms of the tetrapeptide structure (N,N-dimethyl-o-aminobenzoyl)-glycyl-(N'-methyl-L-valyl)-o-aminobenzoic acid. The structure and chirality of viridic acid were confirmed by total synthesis

Spectroscopic surveys of LAMOST

International Nuclear Information System (INIS)

Zhao Yongheng

2015-01-01

The Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST), a new type of reflecting Schmidt telescope, has been designed and produced in China. It marks a breakthrough for large scale spectroscopic survey observation in that both large aperture and wide field of view have been achieved. LAMOST has the highest spectrum acquisition rate, and from October 2011 to June 2014 it has obtained 4.13 million spectra of celestial objects, of which 3.78 million are spectra of stars, with the stellar parameters of 2.20 million stars included. (author)

THE zCOSMOS 10k-BRIGHT SPECTROSCOPIC SAMPLE

International Nuclear Information System (INIS)

Lilly, Simon J.; Maier, Christian; Carollo, Marcella; Caputi, Karina; Le Brun, Vincent; Kneib, Jean-Paul; Le Fevre, Olivier; De la Torre, Sylvain; De Ravel, Loic; Mainieri, Vincenzo; Mignoli, Marco; Zamorani, Gianni; Bardelli, Sandro; Bolzonella, Micol; Coppa, Graziano; Scodeggio, Marco; Contini, Thierry; Renzini, Alvio; Bongiorno, Angela; Cucciati, Olga

2009-01-01

We present spectroscopic redshifts of a large sample of galaxies with I AB -1 , independent of redshift. The reliability of individual redshifts is described by a Confidence Class that has been empirically calibrated through repeat spectroscopic observations of over 600 galaxies. There is very good agreement between spectroscopic and photometric redshifts for the most secure Confidence Classes. For the less secure Confidence Classes, there is a good correspondence between the fraction of objects with a consistent photometric redshift and the spectroscopic repeatability, suggesting that the photometric redshifts can be used to indicate which of the less secure spectroscopic redshifts are likely right and which are probably wrong, and to give an indication of the nature of objects for which we failed to determine a redshift. Using this approach, we can construct a spectroscopic sample that is 99% reliable and which is 88% complete in the sample as a whole, and 95% complete in the redshift range 0.5 < z < 0.8. The luminosity and mass completeness levels of the zCOSMOS-bright sample of galaxies is also discussed.

Synthesis, spectroscopic characterization and acoustic, volumetric, transport and thermal properties of hydroxyl ammonium based ionic liquids

International Nuclear Information System (INIS)

Losetty, Venkatramana; Chennuri, Bharath Kumar; Gardas, Ramesh L.

2016-01-01

Graphical abstract: Density, ρ (■) in kg · m"−"3, speed of sound, u (●) in m · s"−"1, dynamic viscosity, η (▴) in mPa · s, electrical conductivity, σ (♦) in S · cm"−"1of [BHEA][TFA] as the function of temperature and at 0.1 MPa pressure. - Highlights: • N-butyl-(N-hydroxyethyl) ammonium based protic ionic liquids (PILs) were synthesized. • Density, speed of sound, electrical conductivity and viscosity were measured for studied PILs. • Transport property data were fitted to Vogel–Tammann–Fulcher (VTF) equation. • FT-IR spectrum was helpful to explain the hydrogen bonding between ions. • Measured and derived properties were analyzed in terms of chemical structure of PILs. - Abstract: In the present work, solvent-free synthesis of two hydroxyethyl ammonium-based ionic liquids (ILs) at room temperature was carried out namely, N-butyl-(N-hydroxyethyl) ammonium trifluoroacetate ([BHEA][TFA]) and N-butyl-(N-hydroxyethyl) ammonium nitrate ([BHEA][NO_3]). The synthesized ionic liquids were characterized by various spectroscopic techniques such as "1H-NMR, "1"3C-NMR and FTIR. Furthermore, density (ρ), speed of sound (u), electrical conductivity (σ) and viscosity (η) have been measured within the temperature range from T = (303.15 to 343.15) K and at 0.1 MPa pressure. The measured density and viscosity values were fitted to the linear and Vogel–Tammann–Fulcher (VTF) equation, respectively. The temperature dependence conductivity of the measured ILs was fitted to a similar equation type of viscosity (VTF). Furthermore, the refractive index was measured at T = 303.15 K, in turn molar refraction (R_m) and free volume (f_V) were calculated using the Lorentz–Lorenz equation. The thermodynamic properties such as thermal expansion coefficient (α), isentropic compressibility (β_S) and intermolecular free length (L_f) were calculated by using the experimental values of density and speed of sound. The thermal decomposition temperature (T

Natural precursor based hydrothermal synthesis of sodium carbide for reactor applications

Science.gov (United States)

Swapna, M. S.; Saritha Devi, H. V.; Sebastian, Riya; Ambadas, G.; Sankararaman, S.

2017-12-01

Carbides are a class of materials with high mechanical strength and refractory nature which finds a wide range of applications in industries and nuclear reactors. The existing synthesis methods of all types of carbides have problems in terms of use of toxic chemical precursors, high-cost, etc. Sodium carbide (Na2C2) which is an alkali metal carbide is the least explored one and also that there is no report of low-cost and low-temperature synthesis of sodium carbide using the eco-friendly, easily available natural precursors. In the present work, we report a simple low-cost, non-toxic hydrothermal synthesis of refractory sodium carbide using the natural precursor—Pandanus. The formation of sodium carbide along with boron carbide is evidenced by the structural and morphological characterizations. The sample thus synthesized is subjected to field emission scanning electron microscopy (FESEM), x-ray powder diffraction (XRD), ultraviolet (UV)—visible spectroscopy, Fourier transform infrared spectroscopy (FTIR), Raman, and photoluminescent (PL) spectroscopic techniques.

Spectroscopic analysis of optoelectronic semiconductors

CERN Document Server

Jimenez, Juan

2016-01-01

This book deals with standard spectroscopic techniques which can be used to analyze semiconductor samples or devices, in both, bulk, micrometer and submicrometer scale. The book aims helping experimental physicists and engineers to choose the right analytical spectroscopic technique in order to get specific information about their specific demands. For this purpose, the techniques including technical details such as apparatus and probed sample region are described. More important, also the expected outcome from experiments is provided. This involves also the link to theory, that is not subject of this book, and the link to current experimental results in the literature which are presented in a review-like style. Many special spectroscopic techniques are introduced and their relationship to the standard techniques is revealed. Thus the book works also as a type of guide or reference book for people researching in optical spectroscopy of semiconductors.

Boronate esters: Synthesis, characterization and molecular base receptor analysis

Science.gov (United States)

Gómez-Jaimes, Gelen; Barba, Victor

2014-10-01

The synthesis of three boronate esters obtained by reacting 4-fluorophenylboronic (1), 4-iodophenylboronic (2) and 3,4-chlorophenylboronic (3) acids with 2,4,5-trihidroxybenzaldehyde is reported. The structural characterization was determined by spectroscopic and spectrometric techniques. The boron atom was evaluated to acts as Lewis acid center in the reaction with pyridine (Py), triethylamine (TEA) and fluoride anion (F-). The titration method was followed by UV-Vis and 11B NMR spectroscopy; results indicate the good interaction with the fluoride ion but poor coordination towards pyridine in solution.

Novel Fluorinated Indanone, Tetralone and Naphthone Derivatives: Synthesis and Unique Structural Features

Directory of Open Access Journals (Sweden)

Joseph C. Sloop

2012-02-01

Full Text Available Several fluorinated and trifluoromethylated indanone, tetralone and naphthone derivatives have been prepared via Claisen condensations and selective fluorinations in yields ranging from 22–60%. In addition, we report the synthesis of new, selectively fluorinated bindones in yields ranging from 72–92%. Of particular interest is the fluorination and trifluoroacetylation regiochemistry observed in these fluorinated products. We also note unusual transformations including a novel one pot, dual trifluoroacetylation, trifluoroacetylnaphthone synthesis via a deacetylation as well as an acetyl-trifluoroacetyl group exchange. Solid-state structural features exhibited by these compounds were investigated using crystallographic methods. Crystallographic results, supported by spectroscopic data, show that trifluoroacetylated ketones prefer a chelated cis-enol form whereas fluorinated bindone products exist primarily as the cross-conjugated triketo form.

Dual emitter IrQ(ppy)2 for OLED applications: Synthesis and spectroscopic analysis

International Nuclear Information System (INIS)

Ciobotaru, I.C.; Polosan, S.; Ciobotaru, C.C.

2014-01-01

The synthesis of organometallic compound with iridium and two types of ligands, quinoline and phenylpyridine, was done successfully. The absorption spectra of this compound have shown broad peaks in a visible region assigned to metal-to-ligands charge transfer and in UV region assigned to intraligand absorptions. The photoluminescence spectra exhibit dual character in which the red emission is more intense than the green one. In cathodoluminescence measurements, under electron beam, the powder obtained after recrystallization from dichloromethane, shows similar behaviors with photoluminescence spectra. The cathodoluminescence images have shown a luminescent crystalline powder with triclinic structure. This compound exhibits combined vibrational modes, which proves the presence in the same molecule of both ligands. Density Functional Theory calculation was involved in order to identify the main vibrations of this compound. Highlights: • Mixed-ligand of IrQ(ppy) 2 synthesis which gives green and red phosphorescence due to the MCLT processes coming from two types of ligands. • Absorption, photoluminescence, infrared spectroscopy and cathodoluminescence measurements for characterization of IrQ(ppy) 2 organometallic compound. • Experimental results have been compared with the output files obtained from Density Functional Theory by using the Gaussian 03W software

Synthesis and labelling of 19-iodocholesterol 131I

International Nuclear Information System (INIS)

Hamada, E.S.

1979-01-01

Considering the increasing interest in obtaining agents for vizualization of the adrenal gland with radioisotopic techniques, 19-iodocholesterol was prepared by means of chemical synthesis and radioiodine ( 131 I) introduced by isotopic exchange reaction. The reaction product was identified by determination of the melting point and elementary spectroscopic analysis (infra-red absorption and magnetic nuclear ressonance). Radiochemical analysis of the labelled compound was performed by means of then-layer cromatography in silica-gel. In order to confirm its capacity of concentration in the adrenal gland, the distribution of 19-iodocholesterol 131 I, after intravenous injection, was tested in rats. (Author) [pt

Raman Spectroscopic Studies of Methane Gas Hydrates

DEFF Research Database (Denmark)

Hansen, Susanne Brunsgaard; Berg, Rolf W.

2009-01-01

A brief review of the Raman spectroscopic studies of methane gas hydrates is given, supported by some new measurements done in our laboratory.......A brief review of the Raman spectroscopic studies of methane gas hydrates is given, supported by some new measurements done in our laboratory....

Synthesis and Spectroscopic Characterization of Two Tetrasubstituted Cationic Porphyrin Derivatives

Directory of Open Access Journals (Sweden)

Newton M. Barbosa Neto

2011-07-01

Full Text Available An imidazolium tetrasubstituted cationic porphyrin derivative (the free base and its Zn(II complex with five-membered heterocyclic groups in the meso-positions were synthesized using microwave irradiation, and the compounds obtained characterized by 1H-NMR and mass spectrometry. We observed that under microwave irradiation the yield is similar to when the synthesis is performed under conventional heating, however, the time required to prepare the porphyrins decreases enormously. In order to investigate the electronic state of these compounds, we employed UV-Vis and fluorescence spectroscopy combined with quantum chemical calculations. The results reveal the presence, in both compounds, of a large number of electronic states involving the association between the Soret and a blue-shifted band. The Soret band in both compounds also shows a considerable solvent dependence. As for emission, these compounds present low quantum yield at room temperature and no solvent influence on the fluorescence spectra was observed.

Synthesis, spectroscopic and TD-DFT quantum mechanical study of azo-azomethine dyes. A laser induced trans-cis-trans photoisomerization cycle.

Science.gov (United States)

Georgiev, Anton; Kostadinov, Anton; Ivanov, Deyan; Dimov, Deyan; Stoyanov, Simeon; Nedelchev, Lian; Nazarova, Dimana; Yancheva, Denitsa

2018-03-05

This paper describes the synthesis, spectroscopic characterization and quantum mechanical calculations of three azo-azomethine dyes. The dyes were synthesized via condensation reaction between 4-(dimethylamino)benzaldehyde and three different 4-aminobenzene azo dyes. Quantum chemical calculations on the optimized molecular geometry and electron densities of the trans (E) and cis (Z) isomers and their vibrational frequencies have been computed by using DFT/B3LYP density-functional theory with 6-311++G(d,p) basis set in vacuo. The thermodynamic parameters such as total electronic energy E (RB3LYP), enthalpy H 298 (sum of electronic and thermal enthalpies), free Gibbs energy G 298 (sum of electronic and thermal free Gibbs energies) and dipole moment μ were computed for trans (E) and cis (Z) isomers in order to estimate the ΔE trans→cis , Δμ trans→cis, ΔH trans→cis , ΔG trans→cis and ΔS trans→cis values. After molecular geometry optimization the electronic spectra have been obtained by TD-DFT calculations at same basis set and correlated with the spectra of vapour deposited nanosized films of the dyes. The NBO analysis was performed in order to understand the intramolecular charge transfer and energy of resonance stabilization. Solvatochromism was investigated by UV-VIS spectroscopy in five different organic solvents with increasing polarity. The dynamic photoisomerization experiments have been performed in DMF by pump lasers λ=355nm (mostly E→Z) and λ=491nm (mostly Z→E) in spectral region 300nm - 800nm at equal concentrations and times of illumination in order to investigate the photodynamical trans-cis-trans properties of the CHN and NN chromophore groups of the dyes. Copyright © 2017 Elsevier B.V. All rights reserved.

Synthesis, characterization, and photocatalytic properties of core/shell mesoporous silica nanospheres supporting nanocrystalline titania

International Nuclear Information System (INIS)

Cendrowski, K.; Chen, X.; Zielinska, B.; Kalenczuk, R. J.; Rümmeli, M. H.; Büchner, B.; Klingeler, R.; Borowiak-Palen, E.

2011-01-01

The facile bulk synthesis of silica nanospheres makes them an attractive support for the transport of chemical compounds such as nanocrystalline titanium dioxide. In this contribution we present a promising route for the synthesis of mesoporous silica nanospheres (m-SiO 2 ) with diameter in range 200 nm, which are ideal supports for nanocrystalline titanium dioxide (TiO 2 ). The detailed microscopic and spectroscopic characterizations of core/shell structure (m-SiO 2 /TiO 2 ) were conducted. Moreover, the photocatalytic potential of the nanostructures was investigated via phenol decomposition and hydrogen generation. A clear enhancement of photoactivity in both reactions as compared to commercial TiO 2 -Degussa P25 catalyst is detected.

Synthesis, characterization, and photocatalytic properties of core/shell mesoporous silica nanospheres supporting nanocrystalline titania

Science.gov (United States)

Cendrowski, K.; Chen, X.; Zielinska, B.; Kalenczuk, R. J.; Rümmeli, M. H.; Büchner, B.; Klingeler, R.; Borowiak-Palen, E.

2011-11-01

The facile bulk synthesis of silica nanospheres makes them an attractive support for the transport of chemical compounds such as nanocrystalline titanium dioxide. In this contribution we present a promising route for the synthesis of mesoporous silica nanospheres (m-SiO2) with diameter in range 200 nm, which are ideal supports for nanocrystalline titanium dioxide (TiO2). The detailed microscopic and spectroscopic characterizations of core/shell structure (m-SiO2/TiO2) were conducted. Moreover, the photocatalytic potential of the nanostructures was investigated via phenol decomposition and hydrogen generation. A clear enhancement of photoactivity in both reactions as compared to commercial TiO2-Degussa P25 catalyst is detected.

Magnetic nanoparticle supported phosphotungstic acid: An efficient catalyst for the synthesis of xanthene derivatives

Science.gov (United States)

Patel, Nipun; Katheriya, Deepak; Dadhania, Harsh; Dadhania, Abhishek

2018-05-01

Magnetic nanoparticle supported phosphotungstic acid (Fe3O4@SiO2-HPW) was applied as a highly efficient catalyst for the synthesis of 14H-dibenzoxanthene derivatives via condensation reaction of 2-naphthol and aryl aldehydes. The catalyst was found highly efficient for the synthesis of xanthene derivatives under solvent free condition. The catalyst showed high activity and stability during the reaction and provided excellent yield of the corresponding products in short reaction time. All the synthesized compounds were characterized through FT-IR, 1H-NMR and 13C-NMR spectroscopic techniques. Furthermore, the catalyst is magnetically recoverable and can be reused several times without significant loss of its catalytic activity.

Multi-pass spectroscopic ellipsometry

International Nuclear Information System (INIS)

Stehle, Jean-Louis; Samartzis, Peter C.; Stamataki, Katerina; Piel, Jean-Philippe; Katsoprinakis, George E.; Papadakis, Vassilis; Schimowski, Xavier; Rakitzis, T. Peter; Loppinet, Benoit

2014-01-01

Spectroscopic ellipsometry is an established technique, particularly useful for thickness measurements of thin films. It measures polarization rotation after a single reflection of a beam of light on the measured substrate at a given incidence angle. In this paper, we report the development of multi-pass spectroscopic ellipsometry where the light beam reflects multiple times on the sample. We have investigated both theoretically and experimentally the effect of sample reflectivity, number of reflections (passes), angles of incidence and detector dynamic range on ellipsometric observables tanΨ and cosΔ. The multiple pass approach provides increased sensitivity to small changes in Ψ and Δ, opening the way for single measurement determination of optical thickness T, refractive index n and absorption coefficient k of thin films, a significant improvement over the existing techniques. Based on our results, we discuss the strengths, the weaknesses and possible applications of this technique. - Highlights: • We present multi-pass spectroscopic ellipsometry (MPSE), a multi-pass approach to ellipsometry. • Different detectors, samples, angles of incidence and number of passes were tested. • N passes improve polarization ratio sensitivity to the power of N. • N reflections improve phase shift sensitivity by a factor of N. • MPSE can significantly improve thickness measurements in thin films

Green synthesis and characterization of silver nanoparticle using Aloe barbadensis

Energy Technology Data Exchange (ETDEWEB)

Thappily, Praveen, E-mail: pravvmon@gmail.com, E-mail: shiiuvenus@gmail.com; Shiju, K., E-mail: pravvmon@gmail.com, E-mail: shiiuvenus@gmail.com [Laboratory for Molecular Photonics and Electronics (LAMP), Department of Physics, National Institute of Technology, Calicut, Kerala 673601 (India)

2014-10-15

Green synthesis of silver nanoparticles was achieved by simple visible light irradiation using aloe barbadensis leaf extract as reducing agent. UV-Vis spectroscopic analysis was used for confirmation of the successful formation of nanoparticles. Investigated the effect of light irradiation time on the light absorption of the nanoparticles. It is observed that upto 25 minutes of light irradiation, the absorption is linearly increasing with time and after that it becomes saturated. Finally, theoretically fitted the time-absorption graph and modeled a relation between them with the help of simulation software.

Green synthesis and characterization of silver nanoparticle using Aloe barbadensis

International Nuclear Information System (INIS)

Thappily, Praveen; Shiju, K.

2014-01-01

Green synthesis of silver nanoparticles was achieved by simple visible light irradiation using aloe barbadensis leaf extract as reducing agent. UV-Vis spectroscopic analysis was used for confirmation of the successful formation of nanoparticles. Investigated the effect of light irradiation time on the light absorption of the nanoparticles. It is observed that upto 25 minutes of light irradiation, the absorption is linearly increasing with time and after that it becomes saturated. Finally, theoretically fitted the time-absorption graph and modeled a relation between them with the help of simulation software

The synthesis and spectroscopic study of stable free radicals related to piperidine-n-oxyl, including a stable bi-radical

International Nuclear Information System (INIS)

Briere, R.

1965-07-01

A new synthesis of di-tert-butyl nitroxide using the reaction between tert-butyl magnesium chloride and nitro-tert-butane is presented in the first section. Synthesis and investigation of stable free piperidine-N-oxyl radicals are described in the second section. All these nitroxides have been characterised by their I. R., U. V. and E. P. R. absorption spectra. The final section contains a description of the synthesis of a stable bi-radical of the nitroxide type by condensation of 2,2, 6, 6-tetramethyl-piperid-4-one-l-oxyl with hydrazine. (author) [fr

A facile regioselective synthesis of novel spiroacenaphthene pyrroloisoquinolines through 1,3-dipolar cycloaddition reactions

International Nuclear Information System (INIS)

Sarrafi, Yaghoub; Asghari, Asieh; Sadatshahabi, Marzieh; Hamzehloueian, Mahshid; Alimohammadi, Kamal

2013-01-01

An efficient one-pot three-component procedure for the synthesis of novel spiroacenaphthene pyrroloisoquinolines with high regioselectivity is described. These compounds were prepared from 1,3-dipolar cycloaddition of an azomethine ylide generated from acenaphthenequinone and 1,2,3,4-tetrahydroisoquinoline via [1,5]-H shift, with chalcone and nitrostyrene derivatives as dipolarophiles. The structure and stereochemistry of the cycloadducts have been established by single crystal X-ray structure and spectroscopic techniques. (author)

A facile regioselective synthesis of novel spiroacenaphthene pyrroloisoquinolines through 1,3-dipolar cycloaddition reactions

Energy Technology Data Exchange (ETDEWEB)

Sarrafi, Yaghoub; Asghari, Asieh; Sadatshahabi, Marzieh, E-mail: ysarrafi@umz.ac.ir [Department of Organic Chemistry, Faculty of Chemistry, University of Mazandaran (Iran, Islamic Republic of); Hamzehloueian, Mahshid [Department of Chemistry, Jouybar Branch, Islamic Azad University, Jouybar (Iran, Islamic Republic of); Alimohammadi, Kamal [Department of Chemistry, Dr. Shariati Branch, University of Farhangian, Sari (Iran, Islamic Republic of)

2013-12-01

An efficient one-pot three-component procedure for the synthesis of novel spiroacenaphthene pyrroloisoquinolines with high regioselectivity is described. These compounds were prepared from 1,3-dipolar cycloaddition of an azomethine ylide generated from acenaphthenequinone and 1,2,3,4-tetrahydroisoquinoline via [1,5]-H shift, with chalcone and nitrostyrene derivatives as dipolarophiles. The structure and stereochemistry of the cycloadducts have been established by single crystal X-ray structure and spectroscopic techniques. (author)

Synthesis and spectroscopic studies of stable aqueous dispersion of silver nanoparticles.

Science.gov (United States)

El-Shishtawy, Reda M; Asiri, Abdullah M; Al-Otaibi, Maha M

2011-09-01

A facile approach for the synthesis of stable aqueous dispersion of silver nanoparticles (AgNPs) using glucose as the reducing agent in water/micelles system, in which cetyltrimethylammonium bromide (CTAB) was used as capping agent (stabilizer) is described. The evolution of plasmon band of AgNPs was monitored under different conditions such as (a) concentration of sodium hydroxide, (b) concentration of glucose, (c) concentration of silver nitrate (d) concentration of CTAB, and (e) reaction time. AgNPs were characterized by UV-visible spectroscopy, transmission electron microscopy (TEM), fluorescence spectroscopy and FT-IR spectroscopy. The results revealed an easy and viable strategy for obtaining stable aqueous dispersion of AgNPs with well controlled shape and size below 30 nm in diameter. Copyright © 2011 Elsevier B.V. All rights reserved.

Spectroscopic failures in photometric redshift calibration: cosmological biases and survey requirements

Energy Technology Data Exchange (ETDEWEB)

Cunha, Carlos E. [KIPAC, Menlo Park; Huterer, Dragan [Michigan U.; Lin, Huan [Fermilab; Busha, Michael T. [Zurich U.; Wechsler, Risa H. [SLAC

2014-10-11

We use N-body-spectro-photometric simulations to investigate the impact of incompleteness and incorrect redshifts in spectroscopic surveys to photometric redshift training and calibration and the resulting effects on cosmological parameter estimation from weak lensing shear-shear correlations. The photometry of the simulations is modeled after the upcoming Dark Energy Survey and the spectroscopy is based on a low/intermediate resolution spectrograph with wavelength coverage of 5500{\\AA} < {\\lambda} < 9500{\\AA}. The principal systematic errors that such a spectroscopic follow-up encounters are incompleteness (inability to obtain spectroscopic redshifts for certain galaxies) and wrong redshifts. Encouragingly, we find that a neural network-based approach can effectively describe the spectroscopic incompleteness in terms of the galaxies' colors, so that the spectroscopic selection can be applied to the photometric sample. Hence, we find that spectroscopic incompleteness yields no appreciable biases to cosmology, although the statistical constraints degrade somewhat because the photometric survey has to be culled to match the spectroscopic selection. Unfortunately, wrong redshifts have a more severe impact: the cosmological biases are intolerable if more than a percent of the spectroscopic redshifts are incorrect. Moreover, we find that incorrect redshifts can also substantially degrade the accuracy of training set based photo-z estimators. The main problem is the difficulty of obtaining redshifts, either spectroscopically or photometrically, for objects at z > 1.3. We discuss several approaches for reducing the cosmological biases, in particular finding that photo-z error estimators can reduce biases appreciably.

Green synthesis of silver nanoparticles from seed extract of Brassica nigra and its antibacterial activity

Directory of Open Access Journals (Sweden)

RAKSHA PANDIT

2015-05-01

Full Text Available Pandit R. 2015. Green synthesis of silver nanoparticles from seed extract of Brassica nigra and its antibacterial activity. Nusantara Bioscience 7: 15-19. We report the green synthesis of silver nanoparticles using seed extract of Brassica nigra. UV-visible spectroscopic analysis showed the absorbance peak at 432 nm which indicated the synthesis of silver nanoparticles. Nanoparticles Tracking and Analysis (NTA was used to determine the size of synthesized silver nanoparticles. Zeta potential analysis was carried out to study the stability of nanoparticles while FTIR analysis confirmed the presence of proteins as capping agents that provided stability to nanoparticles in colloid. Antibacterial activity of silver nanoparticles was evaluated against Propionibacterium acnes, Pseudomonas aeruginosa and Klebsiella pneumoniae. The activity of Vancomycin was significantly increased in combination with silver nanoparticles showing synergistic activity against all bacteria while the maximum activity was noted against P. acnes.

Synthesis, Characterization, and Biological Activity of Nickel (II and Palladium (II Complex with Pyrrolidine Dithiocarbamate (PDTC

Directory of Open Access Journals (Sweden)

Sk Imadul Islam

2016-01-01

Full Text Available The synthesis of square planar Ni(II and Pd(II complexes with pyrrolidine dithiocarbamate (PDTC was characterized by elemental, physiochemical, and spectroscopic methods. Two complexes were prepared by the reaction of nickel acetate and palladium acetate with pyrrolidine dithiocarbamate (PDTC in 1 : 2 molar ratio. The bovine serum albumin (BSA interaction with complexes was examined by absorption and fluorescence spectroscopic techniques at pH 7.4. All the spectral data suggest that coordination of the pyrrolidine dithiocarbamate (PDTC takes place through the two sulphur atoms in a symmetrical bidentate fashion. All the synthesized compounds were screened for their antimicrobial activity against some species of pathogenic bacteria (Escherichia coli, Vibrio cholerae, Streptococcus pneumonia, and Bacillus cereus. It has been observed that complexes have higher activity than the free ligand.

Synthesis, spectroscopic characterization, crystallographic studies and antibacterial assays of new copper(II) complexes with sulfathiazole and nimesulide

Science.gov (United States)

Nunes, Julia Helena Bormio; de Paiva, Raphael Enoque Ferraz; Cuin, Alexandre; da Costa Ferreira, Ana Maria; Lustri, Wilton Rogério; Corbi, Pedro Paulo

2016-05-01

New ternary copper(II) complexes of sulfathiazole (SFT, C9H8N3O2S2) or nimesulide (NMS, C13H11N2O5S) and 2,2‧-bipyridine (bipy) were synthesized, and characterized by chemical and spectroscopic techniques. Elemental analyses indicated a 2:1:1 sulfonamide/copper/bipy composition for both complexes. Mass spectrometric measurements permitted identifying the molecular ions [Cu(SFT)2(bipy)+H]+ and [Cu(NMS)2(bipy)+H]+ at m/z 728 and 835, respectively, confirming the proposed compositions. Crystal structure of the [Cu(SFT)2(bipy)] complex was solved by powder X-ray diffraction analysis (PXRD), attesting that the Cu(II) ion is hexacoordinated in a distorted octahedral geometry. Each SFT molecule coordinates to the metal ion by the nitrogen atoms of the SO2-N group and of the heterocyclic ring. The coordination sphere is completed by a bipyridine. Electronic paramagnetic resonance (EPR) studies were carried out for the [Cu(NMS)2(bipy)] complex, indicating a tetragonal environment around the metal ion. It was suggested that NMS coordinates to Cu(II) by the nitrogen and oxygen atoms of the SO2-N group, which was confirmed by infrared spectroscopic studies. Biological studies showed the antibacterial activity of both Cu-SFT and Cu-NMS complexes, with the minimum inhibitory concentration (MIC) values ranging from 0.10 to 0.84 mmol L-1 against Gram-negative bacteria for [Cu(SFT)2(bipy)], and from 1.50 to 3.00 mmol L-1 against Gram-positive and -negative bacteria for [Cu(NMS)2(bipy)].

Synthesis, characterization, and evaluation of the antimicrobial efficacy of Boswellia ovalifoliolata stem bark-extract-mediated zinc oxide nanoparticles

Science.gov (United States)

Supraja, N.; Prasad, T. N. V. K. V.; Krishna, T. Giridhara; David, E.

2016-04-01

Synthesis of metal nanoparticles using biological systems is an expanding research area in nanotechnology. Moreover, search for new nanoscale antimicrobials is been always attractive as they find numerous avenues for application in medicine. Biosynthesis of metallic nanoparticles is cost effective and eco-friendly compared to those of conventional methods of nanoparticles synthesis. Herein, we present the synthesis of zinc oxide nanoparticles using the stem bark extract of Boswellia ovalifoliolata, and evaluation of their antimicrobial efficacy. Stable ZnO nanoparticles were formed by treating 90 ml of 1 mM zinc nitrate aqueous solution with 10 ml of 10 % bark extract. The formation of B. ovalifoliolata bark-extract-mediated zinc oxide nanoparticles (BZnNPs) was confirmed by UV-visible spectroscopic analysis and recorded the localized surface plasmon resonance (LSPR) at 230 nm. Fourier transform infrared spectroscopic (FT-IR) analysis revealed that primary and secondary amine groups in combination with the proteins present in the bark extract are responsible for the reduction and stabilization of the BZnNPs. The morphology and crystalline phase of the nanocrystals were determined by Transmission electron microscopy (TEM). The hydrodynamic diameter (20.3 nm) and a positive zeta potential (4.8 mV) were measured using the dynamic light scattering technique. The antimicrobial activity of BZnNPs was evaluated (in vitro) against fungi, Gram-negative, and Gram-positive bacteria using disk diffusion method which were isolated from the scales formed in drinking water PVC pipelines.

Fundamental spectroscopic studies of carbenes and hydrocarbon radicals

Energy Technology Data Exchange (ETDEWEB)

Gottlieb, C.A.; Thaddeus, P. [Harvard Univ., Cambridge, MA (United States)

1993-12-01

Highly reactive carbenes and carbon-chain radicals are studied at millimeter wavelengths by observing their rotational spectra. The purpose is to provide definitive spectroscopic identification, accurate spectroscopic constants in the lowest vibrational states, and reliable structures of the key intermediates in reactions leading to aromatic hydrocarbons and soot particles in combustion.

Synthesis, spectroscopic and thermochemical studies of some novel carbazole-pyridine co-polymers (abstract)

International Nuclear Information System (INIS)

Saeed, A.; Irfan, M.

2011-01-01

Two series of a novel class of carbazole-4-phenylpyridine co-polymers has been synthesized by a modified Chichibabin reaction. The synthesis was carried out by a simple and cheaper method compared to the lengthy methods usually adopted for the preparation of carbazole-pyridine copolymers which involve costly catalysts. All the polymers were characterized by IR, /sup 1/H and /sup 13/C NMR, UV-vis spectroscopy, fluorimetry, TGA and DSC. The weight average molecular masses (M/sub w/) of the polymers were estimated by Laser Light Scattering (LLS) technique. (author)

Sonochemical-assisted magnesium borate synthesis from different boron sources

Directory of Open Access Journals (Sweden)

Yildirim Meral

2017-03-01

Full Text Available In this study, sonochemical-assisted magnesium borate synthesis is studied from different boron sources. Various reaction parameters are successfully applied by a simple and green method. X-ray diffraction (XRD, Fourier transform infrared (FT-IR and Raman spectroscopies are used to characterize the synthesized magnesium borates on the other hand surface morphologies are investigated by using scanning electron microscope (SEM. The XRD analyses showed that the products were admontite [MgO(B2O33 · 7(H2O] with JCPDS (Joint Committee on Powder Diffraction Standards no. of 01-076-0540 and mcallisterite [Mg2(B6O7(OH62 · 9(H2O] with JCPDS no. of 01-070-1902. The results that found in the spectroscopic studies were in a good agreement with characteristic magnesium borate bands in both regions of infra-red and visible. According to SEM results, obtained borates were in micro and sub-micro scales. By the use of ultrasonication, reaction yields were found between 84.2 and 97.9%. As a result, it is concluded that the sonochemical approach is a practicable synthesis method to get high efficiency and high crystallinity in the synthesis magnesium borate compounds.

Gas Chromatography-Mass Spectroscopic (GC-MS) Analysis of n ...

African Journals Online (AJOL)

tuber-regium (synonym Pleurotus tuber regium) using gas chromatography-mass spectroscopic (GC-. MS) techniques. Methods: The n-hexane extract of the sclerotia ... Soxhlet extraction and analysed using gas chromatography-mass spectroscopic (MS) techniques. ..... Phytochemical composition of Pleurotus tuber regium.

Optical constants of graphene measured by spectroscopic ellipsometry

NARCIS (Netherlands)

Weber, J.W.; Calado, V.E.; Van de Sanden, M.C.M.

2010-01-01

A mechanically exfoliated graphene flake ( ? 150×380??m2) on a silicon wafer with 98 nm silicon dioxide on top was scanned with a spectroscopic ellipsometer with a focused spot ( ? 100×55??m2) at an angle of 55°. The spectroscopic ellipsometric data were analyzed with an optical model in which the

Optical constants of graphene measured by spectroscopic ellipsometry

NARCIS (Netherlands)

Weber, J.W.; Calado, V.E.; Sanden, van de M.C.M.

2010-01-01

A mechanically exfoliated graphene flake ( ~ 150×380 µm2) on a silicon wafer with 98 nm silicon dioxide on top was scanned with a spectroscopic ellipsometer with a focused spot ( ~ 100×55 µm2) at an angle of 55°. The spectroscopic ellipsometric data were analyzed with an optical model in which the

Microwave-assisted hydrothermal synthesis of lead zirconate fine powders

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Apinpus Rujiwatra

2011-01-01

Full Text Available A rapid synthesis of lead zirconate fine powders by microwave-assisted hydrothermal technique is reported. The influences of type of lead precursor, concentration of potassium hydroxide mineraliser, applied microwave power and irradiation time are described. The synthesised powders were characterised by powder X-ray diffraction, field emission scanning electron microscopy, energy-dispersive X-ray spectroscopic microanalysis and light scattering technique. The merits of the microwave application in reducing reaction time and improving particle mono-dispersion and size uniformity as well as the drawbacks, viz. low purity of the desired phase and increasing demand of mineraliser, are discussed in relation to conventional heating method.

Synthesis and Characterization of New Polyamides from 1,2-Bis hydrazine Derivatives

International Nuclear Information System (INIS)

Salaha, A.; Abdel-Bary, E.M.; Kandilea, N.G.

2005-01-01

Preparation of polyamides having different chemical structures allows obtaining new materials with different mechanical and physical properties. The difference in the chemical structure depends mainly on the starting reactants used in condensation polymerization of polyamides. In this paper the synthesis of new polyamides based on the condensation polymerization of 1,2- Bis(3-carboxyacryloyl or carboxybenzoyl) hydrazine derivatives and various diamines has been described. The polymers obtained were characterized using spectroscopic and X-ray analysis. Besides thermal stability and electrical conductivity have been evaluated and correlated with the chemical structure of the polyamides obtained

Concise and Straightforward Asymmetric Synthesis of a Cyclic Natural Hydroxy-Amino Acid

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Mario J. Simirgiotis

2014-11-01

Full Text Available An enantioselective total synthesis of the natural amino acid (2S,4R,5R-4,5-di-hydroxy-pipecolic acid starting from D-glucoheptono-1, 4-lactone is presented. The best sequence employed as a key step the intramolecular nucleophilic displacement by an amino function of a 6-O-p-toluene-sulphonyl derivative of a methyl D-arabino-hexonate and involved only 12 steps with an overall yield of 19%. The structures of the compounds synthesized were elucidated on the basis of comprehensive spectroscopic (NMR and MS and computational analysis.

Synthesis and characterization ligand tris-(2-thiosalicylamidoethyl)amine and its iron complexes and indium

International Nuclear Information System (INIS)

Guerra-Garcia, Pedro Pablo; Valle Bourrouet, Grettel

2006-01-01

The synthesis of coordination chemistry ligand tris-(2-tiosalicilamidoetil)amine is presented within the framework of study of tripod ligands, the corresponding complexes of iron and indium. Also, its spectroscopic characterization by proton magnetic resonance is showed; so the influence of ligand on a redox active metal and an inactive is compared. Electrochemical methods have been used. The presence of sulfur atoms modifies the redox and magnetic behavior of iron ion (III), as has been found in other similar ligands [es

Spectroscopic characterization of low dose rate brachytherapy sources

Science.gov (United States)

Beach, Stephen M.

The low dose rate (LDR) brachytherapy seeds employed in permanent radioactive-source implant treatments usually use one of two radionuclides, 125I or 103Pd. The theoretically expected source spectroscopic output from these sources can be obtained via Monte Carlo calculation based upon seed dimensions and materials as well as the bare-source photon emissions for that specific radionuclide. However the discrepancies resulting from inconsistent manufacturing of sources in comparison to each other within model groups and simplified Monte Carlo calculational geometries ultimately result in undesirably large uncertainties in the Monte Carlo calculated values. This dissertation describes experimentally attained spectroscopic outputs of the clinically used brachytherapy sources in air and in liquid water. Such knowledge can then be applied to characterize these sources by a more fundamental and metro logically-pure classification, that of energy-based dosimetry. The spectroscopic results contained within this dissertation can be utilized in the verification and benchmarking of Monte Carlo calculational models of these brachytherapy sources. This body of work was undertaken to establish a usable spectroscopy system and analysis methods for the meaningful study of LDR brachytherapy seeds. The development of a correction algorithm and the analysis of the resultant spectroscopic measurements are presented. The characterization of the spectrometer and the subsequent deconvolution of the measured spectrum to obtain the true spectrum free of any perturbations caused by the spectrometer itself is an important contribution of this work. The approach of spectroscopic deconvolution that was applied in this work is derived in detail and it is applied to the physical measurements. In addition, the spectroscopically based analogs to the LDR dosimetry parameters that are currently employed are detailed, as well as the development of the theory and measurement methods to arrive at these

Synthesis, spectroscopic, biological activity and thermal characterization of ceftazidime with transition metals

Science.gov (United States)

Masoud, Mamdouh S.; Ali, Alaa E.; Elasala, Gehan S.; Kolkaila, Sherif A.

2018-03-01

Synthesis, physicochemical characterization and thermal analysis of ceftazidime complexes with transition metals (Cr(III), Mn(II), Fe(III), Co(II), Ni(II), Cu(II), Zn(II), Cd(II) and Hg(II)) were discussed. It's obtained that ceftazidime act as bidentate ligand. From magnetic measurement and spectral data, octahedral structures were proposed for all complexes except for cobalt, nickel and mercury had tetrahedral structural. Hyper chemistry program confirmed binding sites of ceftazidime. Ceftazidime complexes show higher activity than ceftazidime for some strains. From TG and DTA curves the thermal decomposition mechanisms of ceftazidime and their metal complexes were suggested. The thermal decomposition of the complexes ended with the formation of metal oxides as a final product except in case of Hg complex.

Synthesis and properties of novel 4,5-diaminonaphthalimides

International Nuclear Information System (INIS)

Morris, I.P.

1999-07-01

This thesis presents work carried out into the synthesis and properties of Novel 4,5-diaminonaphthalimides. Previous work had identified that these compounds could be synthesised through a short reaction sequence but a very limited number of examples had been produced. With some modifications, the structure of 4,5-diaminonaphthalimides suggests a number of applications. The diamine functionality suggests the formation of complexes and if chiral amines were used asymmetric synthesis is a possibility. Naphthalimides are known to intercalate into DNA and so compounds of this nature may have interesting anti-cancer activity. Finally diaminonaphthalimides are strongly fluorescent and this in combination with the chelation potential of the diamine functionality may afford ion and molecular sensors. The first section of this thesis reviews these areas of research and demonstrates how diaminonaphthalimides might contribute to these areas. The second section describes the synthesis of 4,5-diaminonaphthalimides and illustrates the variety of compounds that may be synthesised. In addition this section explores the applications to fluorescence sensing and asymmetric synthesis. 4,5-Diaminonaphthalimides are shown to undergo chelation enhanced quenching (CHEQ) and chelation enhanced fluorescence (CHEF) with various transition metal ions. The precise features are shown to be dependent on the metal ion present. The mass spectroscopic results discussed in this section show 4,5-diaminonaphthalimides to be a new class of supramolecular compound as they show pre-assembly around alkali earth metal ions. 4,5-Diaminonaphthalimides were also used as catalysts in asymmetric reactions where they show some catalytic activity in the addition of diethylzinc to benzaldehyde. (author)

One pot electrochemical synthesis of polymer/CNT/metal nanoparticles for fuel cell applications

Science.gov (United States)

Ventrapragada, Lakshman; Zhu, Jingyi; Karakaya, Mehmet; Podila, Ramakrishna; Rao, Apparao; Clemson Nanomaterials center Team

Carbon nanotubes (CNTs) have become a key player in the design of materials for energy applications. They gained their popularity in industrial and scientific research due to their unique properties like excellent conductivity, high surface area, etc. Here we used chemical vapor deposition (CVD) to synthesize two types of CNTs namely, helically coiled CNTs and vertically aligned CNTs. These CNTs were subsequently used to make composites with conducting polymers and metal nanoparticles. One pot electrochemical synthesis was designed to electropolymerize aniline, pyrrole etc. on the surface of the electrode with simultaneous deposition of platinum and gold metal nanoparticles, and CNTs in the polymer matrix. The as synthesized composite materials were characterized with scanning electron microscope for surface morphology and spectroscopic techniques like Raman, UV-Vis for functionality. These were used to study electrocatalytic oxidation of methanol and ethanol for alkaline fuel cell applications. Electrodes fabricated from these composites not only showed good kinetics but also exhibited excellent stability. Uniqueness of this composite lies in its simple two step synthesis and it doesn't involve any surfactants unlike conventional chemical synthesis routes.

Ultrafast Spectroscopic Noninvasive Probe of Vertical Carrier Transport in Heterostructure Devices

Science.gov (United States)

2016-03-01

ARL-TR-7618 ● MAR 2016 US Army Research Laboratory Ultrafast Spectroscopic Noninvasive Probe of Vertical Carrier Transport in...US Army Research Laboratory Ultrafast Spectroscopic Noninvasive Probe of Vertical Carrier Transport in Heterostructure Devices by Blair C...Spectroscopic Noninvasive Probe of Vertical Carrier Transport in Heterostructure Devices 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT

Photocatalytic Properties of Nb/MCM-41 Molecular Sieves: Effect of the Synthesis Conditions

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Caterine Daza Gomez

2015-08-01

Full Text Available The effect of synthesis conditions and niobium incorporation levels on the photocatalytic properties of Nb/MCM-41 molecular sieves was assessed. Niobium pentoxide supported on MCM-41 mesoporous silica was obtained using two methods: sol-gel and incipient impregnation, in each case also varying the percentage of niobium incorporation. The synthesized Nb-MCM-41 ceramic powders were characterized using the spectroscopic techniques of infrared spectroscopy (IR, Raman spectroscopy, X-ray diffraction (XRD, and transmission electron microscopy (TEM. The photodegradation capacity of the powders was studied using the organic molecule, methylene blue. The effect of both the method of synthesis and the percentage of niobium present in the sample on the photodegradation action of the solids was determined. The mesoporous Nb-MCM-41 that produced the greatest photodegradation response was obtained using the sol-gel method and 20% niobium incorporation.

Synthesis and physicochemical investigation of 6,9-bis-pyridino-nido-decaborane(14)

International Nuclear Information System (INIS)

Volkov, V.V.; Myakishev, K.G.; Potapova, O.G.; Polyanskaya, T.M.; Dunaev, S.T.; Il'inchik, E.A.; Bajdina, I.A.; Khudorozhko, G.F.

1988-01-01

The comparative study of B 10 H 12 Py 2 synthesis according to B 1 :0H 14 +2Py=B 10 H 12 Py 2 +H 2 and B 10 H 12 ((CH 3 ) 2 S) 2 +2Py=B 10 H 12 Py 2 +2(CH 3 ) 2 S is carried out. It is shown that synthesis by the second reaction with the high yield of product (97%) is the most effective. In this case the modifications of the B 10 H 12 Py 2 -lemon-colored(2) and orange(2) appear. The specified thermographic, IR-spectroscopic, mass- and NMR-spectral characteristics of the compound are obtained as the data on its electron structure. The crystals of modification (1) are monoclinic, lattice parameters are a=7.804(3), b=14.140(6), c=15.715(5) A, β=107.22(2) deg, Z4

Spectroscopic analysis and molecular docking of imidazole derivatives and investigation of its reactive properties by DFT and molecular dynamics simulations

Science.gov (United States)

Thomas, Renjith; Hossain, Mossaraf; Mary, Y. Sheena; Resmi, K. S.; Armaković, Stevan; Armaković, Sanja J.; Nanda, Ashis Kumar; Ranjan, Vivek Kumar; Vijayakumar, G.; Van Alsenoy, C.

2018-04-01

Solvent-free synthesis pathway for obtaining two imidazole derivatives (2-chloro-1-(4-methoxyphenyl)-4,5-dimethyl-1H-imidazole (CLMPDI) and 1-(4-bromophenyl)-2-chloro-4,5-dimethyl-1H-imidazole (BPCLDI) has been reported in this work, followed by detailed experimental and computational spectroscopic characterization and reactivity study. Spectroscopic methods encompassed IR, FT-Raman and NMR techniques, with the mutual comparison of experimentally and computationally obtained results at DFT/B3LYP level of theory. Reactivity study based on DFT calculations encompassed molecular orbitals analysis, followed by calculations of molecular electrostatic potential (MEP) and average local ionization energy (ALIE) values, Fukui functions and bond dissociation energies (BDE). Additionally, the stability of title molecules in water has been investigated via molecular dynamics (MD) simulations, while interactivity with aspulvinonedimethylallyl transferase protein has been evaluated by molecular docking procedure. CLMPDI compound showed antimicrobial activity against all four bacterial strain in both gram positive and gram negative bacteria while, BPCLDI showed only in gram positive bacteria, Staphylococcus Aureus (MTCC1144). The first order hyperpolarizability of CLMPDI and BPCLDI are 20.15 and 6.10 times that of the standard NLO material urea.

Synthesis of 2,6-diisopropyl-phenylcarbamoylmethyl-iminodiacetic acid (DISIDA) and 4-n-p-butyl-phenylcarbamoylmethyl-iminodiacetic acid (BUTYL-IDA). Preparation of lyophilized kit to be used as 99(supm)Tc agent in hepatobiliary system

International Nuclear Information System (INIS)

Hamada, E.S.; Barbosa, M.F. de; Theodora, M.A.; Almeida, M. de; Colturato, M.T.; Muramoto, E.; Silva, C.P.G. da.

1987-08-01

The synthesis of 2,6 diisopropyl IDA (DISIDA) and 4-n-butyl IDA (BUTIL-IDA) is described. Their spectroscopic properties, radiopharmaceutical preparation and their use as 99 (sup m)Tc complex agent in hepatobiliary studies, are also reported. (Author) [pt

Spectroscopic and imaging diagnostics of pulsed laser deposition laser plasmas

International Nuclear Information System (INIS)

Thareja, Raj K.

2002-01-01

An overview of laser spectroscopic techniques used in the diagnostics of laser ablated plumes used for thin film deposition is given. An emerging laser spectroscopic imaging technique for the laser ablation material processing is discussed. (author)

Understanding reactivity of two newly synthetized imidazole derivatives by spectroscopic characterization and computational study

Science.gov (United States)

Hossain, Mossaraf; Thomas, Renjith; Mary, Y. Sheena; Resmi, K. S.; Armaković, Stevan; Armaković, Sanja J.; Nanda, Ashis Kumar; Vijayakumar, G.; Van Alsenoy, C.

2018-04-01

Two newly synthetized imidazole derivatives (1-(4-methoxyphenyl)-4,5-dimethyl-1H-imidazole-2-yl acetate (MPDIA) and 1-(4-bromophenyl)-4,5-dimethyl-1H-imidazole-2-yl acetate (BPDIA)) have been prepared by solvent-free synthesis pathway and their specific spectroscopic and reactive properties have been discussed based on combined experimental and computational approaches. Aside of synthesis, experimental part of this work included measurements of IR, FT-Raman and NMR spectra. All of the aforementioned spectra were also obtained computationally, within the framework of density functional theory (DFT) approach. Additionally, DFT calculations have been used in order to investigate local reactivity properties based on molecular orbital theory, molecular electrostatic potential (MEP), average local ionization energy (ALIE), Fukui functions and bond dissociation energy (BDE). Molecular dynamics (MD) simulations have been used in order to obtain radial distribution functions (RDF), which were used for identification of the atoms with pronounced interactions with water molecules. MEP showed negative regions are mainly localized over N28, O29, O35 atoms, it is represent with red colour in rainbow color scheme for MPDIA and BPDIA (which are most reactive sites for electrophilic attack). The first order hyperpolarizabilities of MPDIA and BPDIA are 20.15 and 6.10 times that of the standard NLO material urea. Potential interaction with antihypertensive protein hydrolase.

Simple preparation of new N-aryl-N-(3-indolmethyl acetamides and their spectroscopic analysis

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José A. Henao

2009-12-01

Full Text Available To prepare new indolic molecules and characterize them by spectroscopic methods. Materials and methods: All reagentswere purchased from Aldrich, commercial grade. The purity of the products and the composition of the reaction mixtures were monitoredby thin layer chromatography over Silufol UV254 0.25 mm-thick chromatoplates. Product isolation and purification were performed bycolumn chromatography (SiO2, using ethyl acetate-petroleum ether mixtures as eluents. Results. The synthesis of new N-aryl-N-(3-indolmethyl acetamides based on first step iminization reaction of indol-3-carbaldehyde is accomplished. The structures of the C-3substituted indoles were confirmed by 1H-NMR and 13C-NMR studies supported by inverse-detected 2D NMR experiments and alsothrough monocrystal X-ray diffraction. Conclusions. An efficient, economic, and fast synthetic route was designed to the construction ofthe N-aryl-N-(3-indolmethyl acetamides, structural analogues of some alkaloids.

Obtaining the Electron Angular Momentum Coupling Spectroscopic Terms, jj

Science.gov (United States)

Orofino, Hugo; Faria, Roberto B.

2010-01-01

A systematic procedure is developed to obtain the electron angular momentum coupling (jj) spectroscopic terms, which is based on building microstates in which each individual electron is placed in a different m[subscript j] "orbital". This approach is similar to that used to obtain the spectroscopic terms under the Russell-Saunders (LS) coupling…

Iterative estimation of the background in noisy spectroscopic data

International Nuclear Information System (INIS)

Zhu, M.H.; Liu, L.G.; Cheng, Y.S.; Dong, T.K.; You, Z.; Xu, A.A.

2009-01-01

In this paper, we present an iterative filtering method to estimate the background of noisy spectroscopic data. The proposed method avoids the calculation of the average full width at half maximum (FWHM) of the whole spectrum and the peak regions, and it can estimate the background efficiently, especially for spectroscopic data with the Compton continuum.

Spectroscopic databases - A tool for structure elucidation

Energy Technology Data Exchange (ETDEWEB)

Luksch, P [Fachinformationszentrum Karlsruhe, Gesellschaft fuer Wissenschaftlich-Technische Information mbH, Eggenstein-Leopoldshafen (Germany)

1990-05-01

Spectroscopic databases have developed to useful tools in the process of structure elucidation. Besides the conventional library searches, new intelligent programs have been added, that are able to predict structural features from measured spectra or to simulate for a given structure. The example of the C13NMR/IR database developed at BASF and available on STN is used to illustrate the present capabilities of online database. New developments in the field of spectrum simulation and methods for the prediction of complete structures from spectroscopic information are reviewed. (author). 10 refs, 5 figs.

Analysis of transfer reactions: determination of spectroscopic factors

Energy Technology Data Exchange (ETDEWEB)

Keeley, N. [CEA Saclay, Dept. d' Astrophysique, de Physique des Particules de Physique Nucleaire et de l' Instrumentation Associee (DSM/DAPNIA/SPhN), 91- Gif sur Yvette (France); The Andrzej So an Institute for Nuclear Studies, Dept. of Nuclear Reactions, Warsaw (Poland)

2007-07-01

An overview of the most popular models used for the analysis of direct reaction data is given, concentrating on practical aspects. The 4 following models (in order of increasing sophistication): the distorted wave born approximation (DWBA), the adiabatic model, the coupled channels born approximation, and the coupled reaction channels are briefly described. As a concrete example, the C{sup 12}(d,p)C{sup 13} reaction at an incident deuteron energy of 30 MeV is analysed with progressively more physically sophisticated models. The effect of the choice of the reaction model on the spectroscopic information extracted from the data is investigated and other sources of uncertainty in the derived spectroscopic factors are discussed. We have showed that the choice of the reaction model can significantly influence the nuclear structure information, particularly the spectroscopic factors or amplitudes but occasionally also the spin-parity, that we wish to extract from direct reaction data. We have also demonstrated that the DWBA can fail to give a satisfactory description of transfer data but when the tenets of the theory are fulfilled DWBA can work very well and will yield the same results as most sophisticated models. The use of global rather than fitted optical potentials can also lead to important differences in the extracted spectroscopic factors.

Spectroscopic Parameters of Lumbar Intervertebral Disc Material

Science.gov (United States)

Terbetas, G.; Kozlovskaja, A.; Varanius, D.; Graziene, V.; Vaitkus, J.; Vaitkuviene, A.

2009-06-01

There are numerous methods of investigating intervertebral disc. Visualization methods are widely used in clinical practice. Histological, imunohistochemical and biochemical methods are more used in scientific research. We propose that a new spectroscopic investigation would be useful in determining intervertebral disc material, especially when no histological specimens are available. Purpose: to determine spectroscopic parameters of intervertebral disc material; to determine emission spectra common for all intervertebral discs; to create a background for further spectroscopic investigation where no histological specimen will be available. Material and Methods: 20 patients, 68 frozen sections of 20 μm thickness from operatively removed intervertebral disc hernia were excited by Nd:YAG microlaser STA-01-TH third harmonic 355 nm light throw 0, 1 mm fiber. Spectrophotometer OceanOptics USB2000 was used for spectra collection. Mathematical analysis of spectra was performed by ORIGIN multiple Gaussian peaks analysis. Results: In each specimen of disc hernia were found distinct maximal spectral peaks of 4 types supporting the histological evaluation of mixture content of the hernia. Fluorescence in the spectral regions 370-700 nm was detected in the disc hernias. The main spectral component was at 494 nm and the contribution of the components with the peak wavelength values at 388 nm, 412 nm and 435±5 nm were varying in the different groups of samples. In comparison to average spectrum of all cases, there are 4 groups of different spectral signatures in the region 400-500 nm in the patient groups, supporting a clinical data on different clinical features of the patients. Discussion and Conclusion: besides the classical open discectomy, new minimally invasive techniques of treating intervertebral disc emerge (PLDD). Intervertebral disc in these techniques is assessed by needle, no histological specimen is taken. Spectroscopic investigation via fiber optics through the

Spectroscopic amplifier for pin diode

International Nuclear Information System (INIS)

Alonso M, M. S.; Hernandez D, V. M.; Vega C, H. R.

2014-10-01

The photodiode remains the basic choice for the photo-detection and is widely used in optical communications, medical diagnostics and field of corpuscular radiation. In detecting radiation it has been used for monitoring radon and its progeny and inexpensive spectrometric systems. The development of a spectroscopic amplifier for Pin diode is presented which has the following characteristics: canceler Pole-Zero (P/Z) with a time constant of 8 μs; constant gain of 57, suitable for the acquisition system; 4th integrator Gaussian order to waveform change of exponential input to semi-Gaussian output and finally a stage of baseline restorer which prevents Dc signal contribution to the next stage. The operational amplifier used is the TLE2074 of BiFET technology of Texas Instruments with 10 MHz bandwidth, 25 V/μs of slew rate and a noise floor of 17 nv/(Hz)1/2. The integrated circuit has 4 operational amplifiers and in is contained the total of spectroscopic amplifier that is the goal of electronic design. The results show like the exponential input signal is converted to semi-Gaussian, modifying only the amplitude according to the specifications in the design. The total system is formed by the detector, which is the Pin diode, a sensitive preamplifier to the load, the spectroscopic amplifier that is what is presented and finally a pulse height analyzer (Mca) which is where the spectrum is shown. (Author)

ON THE SPECTROSCOPIC CLASSES OF NOVAE IN M33

International Nuclear Information System (INIS)

Shafter, A. W.; Darnley, M. J.; Bode, M. F.; Ciardullo, R.

2012-01-01

We report the initial results from an ongoing multi-year spectroscopic survey of novae in M33. The survey resulted in the spectroscopic classification of six novae (M33N 2006-09a, 2007-09a, 2009-01a, 2010-10a, 2010-11a, and 2011-12a) and a determination of rates of decline (t 2 times) for four of them (2006-09a, 2007-09a, 2009-01a, and 2010-10a). When these data are combined with existing spectroscopic data for two additional M33 novae (2003-09a and 2008-02a), we find that five of the eight novae with available spectroscopic class appear to be members of either the He/N or Fe IIb (hybrid) classes, with only two clear members of the Fe II spectroscopic class. This initial finding is very different from what would be expected based on the results for M31 and the Galaxy where Fe II novae dominate, and the He/N and Fe IIb classes together make up only ∼20% of the total. It is plausible that the increased fraction of He/N and Fe IIb novae observed in M33 thus far may be the result of the younger stellar population that dominates this galaxy, which is expected to produce novae that harbor generally more massive white dwarfs than those typically associated with novae in M31 or the Milky Way.

Spectroscopic studies of the transplutonium elements

International Nuclear Information System (INIS)

Carnall, W.T.; Conway, J.G.

1983-01-01

The challenging opportunity to develop insights into both atomic structure and the effects of bonding in compounds makes the study of actinide spectroscopy a particularly fruitful and exciting area of scientific endeavor. It is also the interpretation of f-element spectra that has stimulated the development of the most sophisticated theoretical modeling attempted for any elements in the periodic table. The unique nature of the spectra and the wealth of fine detail revealed make possible sensitive tests of both physical models and the results of Hartree-Fock type ab initio calculations. This paper focuses on the unique character of heavy actinide spectroscopy. It discusses how it differs from that of the lighter member of the series and what are the special properties that are manifested. Following the introduction, the paper covers the following: (1) the role of systematic studies and the relationships of heavy-actinide spectroscopy to ongoing spectroscopic investigations of the lighter members of the series; (2) atomic (free-ion) spectra which covers the present status of spectroscopic studies with transplutonium elements, and future needs and directions in atomic spectroscopy; (3) the spectra of actinide compounds which covers the present status and future directions of spectroscopic studies with compounds of the transplutonium elements; and other spectroscopies. 1 figure, 2 tables

Hydrothermal synthesis, structural elucidation, spectroscopic studies, thermal behavior and luminescence properties of a new 3-d compound: FeAlF2(C10H8N2)(HPO4)2(H2O)

Science.gov (United States)

Bouzidia, Nabaa; Salah, Najet; Hamdi, Besma; Ben Salah, Abdelhamid

2017-04-01

The study of metal phosphate has been a proactive field of research thanks to its applied and scientific importance, especially in terms of the development of optical devices such as solid state lasers as well as optical fibers. The present paper seeks to investigate the synthesis, crystal structure, elemental analysis and properties of FeAlF2(C10H8N2)(HPO4)2(H2O) compound investigated by spectroscopic studies (FT-IR and FT-Raman), thermal behavior and luminescence. The Hirshfeld surface analysis and 2-D fingerprint plot have been performed to explore the behavior of these weak interactions and crystal cohesion. This investigation shows that the molecules are connected by hydrogen bonds of the type Osbnd H⋯O and Osbnd H⋯F. In addition, the 2,2'‒bipyridine ligand plays a significant role in the construction of 3-D supramolecular framework via π‒π stacking. FT‒IR and FT‒Raman spectra were used so as to ease the responsibilities of the vibration modes of the title compound. The thermal analysis (TGA) study shows a mass loss evolution as a temperature function. Finally, the optical properties were evaluated by photoluminescence spectroscopy.

Synthesis and characterization of semi-IPNs based on PVP and PLLA

International Nuclear Information System (INIS)

Camilo, A.P.R.; Mano, V.; Felisberti, M.I.

2010-01-01

The specific interest in the synthesis of semi-IPNs based on PLLA and PVP homopolymers due to the fact these are biodegradable and biocompatible, which allows us to infer applications in the medical field as sutures, implants, matrices for controlled release of drugs etc. The objective was to prepare a multicomponent material amphiphile in the form of semi-interpenetrating polymer networks, based on poly (L-lactide), PLLA, hydrophobic homopolymer, and poly (vinylpyrrolidone), PVP, hydrophilic component. The preparation of semi-IPN combined the polymerization and crosslinking of N-vinylpyrrolidone in the presence of poly (L-lactide). The products were characterized by spectroscopic and thermal methods. (author)

Nuclear resonance vibrational spectroscopic studies of iron-containing biomolecules

International Nuclear Information System (INIS)

Ohta, Takehiro; Seto, Makoto

2014-01-01

In this review, we report recent nuclear resonance vibrational spectroscopic (NRVS) studies of iron-containing biomolecules and their model complexes. The NRVS is synchrotron-based element-specific vibrational spectroscopic methods. Unlike Raman and infrared spectroscopy, the NRVS can investigate all iron motions without selection rules, which provide atomic level insights into the structure/reactivity correlation of biologically relevant iron complexes. (author)

Cytotoxic 1,3-Thiazole and 1,2,4-Thiadiazole Alkaloids from Penicillium oxalicum: Structural Elucidation and Total Synthesis

Directory of Open Access Journals (Sweden)

Zheng Yang

2016-02-01

Full Text Available Two new thiazole and thiadiazole alkaloids, penicilliumthiamine A and B (2 and 3, were isolated from the culture broth of Penicillium oxalicum, a fungus found in Acrida cinerea. Their structures were elucidated mainly by spectroscopic analysis, total synthesis and X-ray crystallographic analysis. Biological evaluations indicated that compound 1, 3a and 3 exhibit potent cytotoxicity against different cancer cell lines through inhibiting the phosphorylation of AKT/PKB (Ser 473, one of important cancer drugs target.

Probing superconductors. Spectroscopic-imaging scanning tunneling microscopy

International Nuclear Information System (INIS)

Hanaguri, Tetsuo

2011-01-01

Discovery of high-temperature superconductivity in a cuprate triggered developments of various spectroscopic tools which have been utilized to elucidate electronic states of this mysterious compound. Particularly, angle-resolved photoemission spectroscopy and scanning-tunneling microscopy/spectroscopy are improved considerably. It is now possible to map the superconducting gap in both momentum and real spaces using these two techniques. Here we review spectroscopic-imaging scanning tunneling microscopy which is able to explore momentum-space phase structure of the superconducting gap, as well as real-space structure. Applications of this technique to a cuprate and an iron-based superconductor are discussed. (author)

Synthesis of Chalcone and Flavanone Compound Using Raw Material of Acetophenone and Benzaldehyde Derivative

Directory of Open Access Journals (Sweden)

Ismiyarto Ismiyarto

2010-06-01

Full Text Available Synthesis of flavanoid compounds of chalcone and flavanone groups have been conducted. Flavanoid Is one of the group natural products which is mostly found in plants and have been proved to have physiological activity as drug. In this research, chalcone proup compounds that being synthesized are: chalcone, 3,4-dimethoxychalcone, 2'-hidroxy-3,4-dimethoxychalcone where as compound of flavanone group that being synthesized is 3',4'-dimethoxyflavanone. The synthesis of chalcone group are carried out based on Claisen-Schmidt reaction by using raw material of aromatic aldehydes and aromatic ketones. The synthesis in carried out by stirring at the room temperature using alkali solution as catalyst and ethanol as solvent. The synthesis of 3',4'-dimethoxyflanone is made based on the nucleophilic 1,4 addition of the unsaturated α,β ketone. The synthesis is made by refluxing 2'-hydroxy-3,4-dimethoxychalcone in alkali condition for 12 hours. The identification of flavanoid compound is carried out by using spectroscopic IR, GC-MS and 1H-NMR methods. The result of each synthesis chalcone group are follows: chalcone as yellowish solid with m.p= 50 °C and the yield is 83.39%; 3,4-dimethoxychalcone as yellow solid with m.p= 57°C and the yield is 76.00% ; 2'-hydroxy-3,4-dimethoxychalcone as orange solid with m.p= 90 °C and the yield is 74.29%, for 3',4'-dimethoxyflavanone as pale yellow solid with m.p= 80 °C and the yield is 72.00%.

Synthesis, structure, morphology and stoichiometry characterization of cluster and nano magnetite

Energy Technology Data Exchange (ETDEWEB)

Singh, L. Herojit; Pati, S.S. [Institute of Physics, University of Brasilia, 70919-970, Brasilia, DF (Brazil); Guimarães, Edi M. [Institute of Geoscience, University of Brasilia, 70910-900, Brasilia, DF (Brazil); Rodrigues, P.A.M.; Oliveira, Aderbal C. [Institute of Physics, University of Brasilia, 70919-970, Brasilia, DF (Brazil); Garg, V.K., E-mail: vijgarg@gmail.com [Institute of Physics, University of Brasilia, 70919-970, Brasilia, DF (Brazil)

2016-08-01

We have studied the stoichiometry of magnetite nanoparticles using three spectroscopic techniques: Mössbauer, photoacoustic and ferromagnetic resonance (FMR). By varying the weight ratio of the Fe precursor to the reducing agent (sodium acetate) and a post-synthesis annealing, we were able to synthesize samples with different amounts of Fe vacancies, from stoichiometric Fe{sub 3}O{sub 4} to γ-Fe{sub 2}O{sub 3}. By synthesizing magnetite in the presence of zeolite we obtained nanoparticles within the 3–10 nm diameter range. The spectroscopic results show that there is a correlation between the amount of Fe vacancies and (i) the optical absorption and (ii) the g-values from the Electron paramagnetic resonance EPR spectra of the nanoparticles. - Highlights: • Magnetite nanoparticles and cluster synthesized. • Photoacoustic spectroscopy is effective in determining the stoichiometry. • Particles with 9 nm size has 0 < δ < 0.14. • Less than 9 nm gives 0.14 < δ < 0.3 and size <3 nm have δ = 0.33 (i.e. γ-Fe{sub 2}O{sub 3}).

Passive Spectroscopic Diagnostics for Magnetically-confined Fusion Plasmas

International Nuclear Information System (INIS)

Stratton, B.C.; Bitter, M.; Hill, K.W.; Hillis, D.L.; Hogan, J.T.

2007-01-01

Spectroscopy of radiation emitted by impurities and hydrogen isotopes plays an important role in the study of magnetically-confined fusion plasmas, both in determining the effects of impurities on plasma behavior and in measurements of plasma parameters such as electron and ion temperatures and densities, particle transport, and particle influx rates. This paper reviews spectroscopic diagnostics of plasma radiation that are excited by collisional processes in the plasma, which are termed 'passive' spectroscopic diagnostics to distinguish them from 'active' spectroscopic diagnostics involving injected particle and laser beams. A brief overview of the ionization balance in hot plasmas and the relevant line and continuum radiation excitation mechanisms is given. Instrumentation in the soft X-ray, vacuum ultraviolet, ultraviolet, visible, and near-infrared regions of the spectrum is described and examples of measurements are given. Paths for further development of these measurements and issues for their implementation in a burning plasma environment are discussed.

Passive Spectroscopic Diagnostics for Magnetically-confined Fusion Plasmas

Energy Technology Data Exchange (ETDEWEB)

Stratton, B. C.; Biter, M.; Hill, K. W.; Hillis, D. L.; Hogan, J. T.

2007-07-18

Spectroscopy of radiation emitted by impurities and hydrogen isotopes plays an important role in the study of magnetically-confined fusion plasmas, both in determining the effects of impurities on plasma behavior and in measurements of plasma parameters such as electron and ion temperatures and densities, particle transport, and particle influx rates. This paper reviews spectroscopic diagnostics of plasma radiation that are excited by collisional processes in the plasma, which are termed 'passive' spectroscopic diagnostics to distinguish them from 'active' spectroscopic diagnostics involving injected particle and laser beams. A brief overview of the ionization balance in hot plasmas and the relevant line and continuum radiation excitation mechanisms is given. Instrumentation in the soft X-ray, vacuum ultraviolet, ultraviolet, visible, and near-infrared regions of the spectrum is described and examples of measurements are given. Paths for further development of these measurements and issues for their implementation in a burning plasma environment are discussed.

THE BARYON OSCILLATION SPECTROSCOPIC SURVEY OF SDSS-III

International Nuclear Information System (INIS)

Dawson, Kyle S.; Ahn, Christopher P.; Bolton, Adam S.; Schlegel, David J.; Bailey, Stephen; Anderson, Scott F.; Bhardwaj, Vaishali; Aubourg, Éric; Bautista, Julian E.; Barkhouser, Robert H.; Beifiori, Alessandra; Berlind, Andreas A.; Bizyaev, Dmitry; Brewington, Howard; Blake, Cullen H.; Blanton, Michael R.; Blomqvist, Michael; Borde, Arnaud; Bovy, Jo; Brandt, W. N.

2013-01-01

The Baryon Oscillation Spectroscopic Survey (BOSS) is designed to measure the scale of baryon acoustic oscillations (BAO) in the clustering of matter over a larger volume than the combined efforts of all previous spectroscopic surveys of large-scale structure. BOSS uses 1.5 million luminous galaxies as faint as i = 19.9 over 10,000 deg 2 to measure BAO to redshifts z A to an accuracy of 1.0% at redshifts z = 0.3 and z = 0.57 and measurements of H(z) to 1.8% and 1.7% at the same redshifts. Forecasts for Lyα forest constraints predict a measurement of an overall dilation factor that scales the highly degenerate D A (z) and H –1 (z) parameters to an accuracy of 1.9% at z ∼ 2.5 when the survey is complete. Here, we provide an overview of the selection of spectroscopic targets, planning of observations, and analysis of data and data quality of BOSS.

Dye incorporation in polyphosphate gels: synthesis and theoretical calculations

Directory of Open Access Journals (Sweden)

Jordan Del Nero

2003-06-01

Full Text Available In this work we described theoretical calculations on the electronic structure and optical properties of the dyes crystal violet and malachite green based in semiempirical methods (Parametric Method 3 and Intermediate Neglect of Differential Overlap / Spectroscopic - Configuration Interaction and the synthesis of a new hybrid material based upon the incorporation of these dyes in an aluminum polyphosphate gel network. The samples are nearly transparent, free-standing thick films. The optical properties of the entrapped dyes are sensitive to chemical changes within the matrix caused either by gel aging or external stimulli such as exposition to acidic and basic vapors that can percolate within the matrix. Our theoretical modeling is in good agreement with the experimental results for the dyes.

Antihydrogen synthesis in a double-CUSP trap towards test of the CPT-symmetry

Energy Technology Data Exchange (ETDEWEB)

Radics, B., E-mail: balint.radics@cern.ch [ETH Zürich, Institute for Particle Physics (Switzerland); Ishikawa, S.; Kuroda, N. [University of Tokyo, Institute of Physics, Graduate School of Arts and Sciences (Japan); Murtagh, D. J.; Nagata, Y. [RIKEN, Atomic Physics Laboratory (Japan); Tajima, M. [University of Tokyo, Institute of Physics, Graduate School of Arts and Sciences (Japan); Gorp, S. Van [RIKEN, Atomic Physics Laboratory (Japan); Abo, Y. [Hiroshima University, Graduate School of Advanced Sciences of Matter (Japan); Dupre, P. [RIKEN, Atomic Physics Laboratory (Japan); Higashi, Y. [University of Tokyo, Institute of Physics, Graduate School of Arts and Sciences (Japan); Kaga, C. [Hiroshima University, Graduate School of Advanced Sciences of Matter (Japan); Leali, M.; Mascagna, V.; Venturelli, L.; Zurlo, N. [Universita di Brescia, Dipartimento di Ingegneria dell Informazione (Italy); Breuker, H. [CERN (Switzerland); Higaki, H. [Hiroshima University, Graduate School of Advanced Sciences of Matter (Japan); Kanai, Y. [RIKEN, Atomic Physics Laboratory (Japan); Rizzini, E. Lodi [Universita di Brescia, Dipartimento di Ingegneria dell Informazione (Italy); Matsuda, Y. [University of Tokyo, Institute of Physics, Graduate School of Arts and Sciences (Japan); and others

2016-12-15

The aim of the ASACUSA-CUSP experiment at CERN is to produce a cold, polarised antihydrogen beam and perform a high precision measurement of the ground-state hyperfine transition frequency of the antihydrogen atom and compare it with that of the hydrogen atom using the same spectroscopic beam line. Towards this goal a significant step was successfully accomplished: synthesised antihydrogen atoms have been produced in a CUSP magnetic configuration and detected at the end of our spectrometer beam line in 2012 [1]. During a long shut down at CERN the ASACUSA-CUSP experiment had been renewed by introducing a new double-CUSP magnetic configuration and a new semi-cylindrical tracking detector (AMT) [2], and by improving the transport feature of low energy antiproton beams. The new tracking detector monitors the antihydrogen synthesis during the mixing cycle of antiprotons and positrons. In this work the latest results and improvements of the antihydrogen synthesis will be presented including highlights from the last beam time.

Wet chemical synthesis of soluble gold nanogaps

DEFF Research Database (Denmark)

Jain, Titoo; Tang, Qingxin; Bjørnholm, Thomas

2014-01-01

NRs) in aqueous solution. Through controlled end-to-end assembly of the AuNRs into dimers or chains, facilitated via target molecules, they can be used as electrical contacts. In this way, the preparation of AuNR-molecule-AuNR junctions by wet chemical methods may afford a large number of identical devices...... with little variation in the interface between molecule and electrode (AuNR). In this Account, we highlight recent progress in using chemically synthesized AuNRs as building blocks for molecular electronic applications. We outline the general synthesis and properties of AuNRs and describe the aqueous growth...... in the nanogaps lets us spectroscopically characterize the molecules via surface-enhanced Raman scattering. We discuss the incorporation of oligopeptides functionalized with acetylene units having uniquely identifiable vibrational modes. This acetylene moiety allows chemical reactions to be performed in the gaps...

Development of a THz spectroscopic imaging system

International Nuclear Information System (INIS)

Usami, M; Iwamoto, T; Fukasawa, R; Tani, M; Watanabe, M; Sakai, K

2002-01-01

We have developed a real-time THz imaging system based on the two-dimensional (2D) electro-optic (EO) sampling technique. Employing the 2D EO-sampling technique, we can obtain THz images using a CCD camera at a video rate of up to 30 frames per second. A spatial resolution of 1.4 mm was achieved. This resolution was reasonably close to the theoretical limit determined by diffraction. We observed not only static objects but also moving ones. To acquire spectroscopic information, time-domain images were collected. By processing these images on a computer, we can obtain spectroscopic images. Spectroscopy for silicon wafers was demonstrated

Spectroscopic data

CERN Document Server

Melzer, J

1976-01-01

During the preparation of this compilation, many people contributed; the compilers wish to thank all of them. In particular they appreciate the efforts of V. Gilbertson, the manuscript typist, and those of K. C. Bregand, J. A. Kiley, and W. H. McPherson, who gave editorial assistance. They would like to thank Dr. J. R. Schwartz for his cooperation and encouragement. In addition, they extend their grati­ tude to Dr. L. Wilson of the Air Force Weapons Laboratory, who gave the initial impetus to this project. v Contents I. I ntroduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 . . . . . . . . . . . . . . . . 11. Organization ofthe Spectroscopic Table. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 Methods of Production and Experimental Technique . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 Band Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2...

Template synthesis of highly crystalline and monodisperse iron oxide pigments of nanosize

International Nuclear Information System (INIS)

Sreeram, Kalarical Janardhanan; Indumathy, Ramasamy; Rajaram, Ananthanarayanan; Nair, Balachandran Unni; Ramasami, Thirumalachari

2006-01-01

Synthesis of highly crystalline and monodisperse iron oxide nanoparticles is reported. The separation of Fe centers through site-specific binding to a polysaccharide-alginate matrix enables the generation of particles with a monodisperse or narrow size distribution character, resulting in transparent pigments. Site-specific interactions coupled with gel like character of alginate is proposed as the mechanism behind generation of lower particle sizes. Alginate-Fe complexes developed were subjected to heat treatment to provide for crystalline character and development of hematite (α-Fe 2 O 3 ). Conditions most ideal for achieving monodispersity and lower sizes have been optimized and confirmed through microscopic and photon correlation spectroscopic measurements

Spectroscopic Chemical Analysis Methods and Apparatus

Science.gov (United States)

Hug, William F. (Inventor); Reid, Ray D. (Inventor); Bhartia, Rohit (Inventor); Lane, Arthur L. (Inventor)

2018-01-01

Spectroscopic chemical analysis methods and apparatus are disclosed which employ deep ultraviolet (e.g. in the 200 nm to 300 nm spectral range) electron beam pumped wide bandgap semiconductor lasers, incoherent wide bandgap semiconductor light emitting devices, and hollow cathode metal ion lasers to perform non-contact, non-invasive detection of unknown chemical analytes. These deep ultraviolet sources enable dramatic size, weight and power consumption reductions of chemical analysis instruments. In some embodiments, Raman spectroscopic detection methods and apparatus use ultra-narrow-band angle tuning filters, acousto-optic tuning filters, and temperature tuned filters to enable ultra-miniature analyzers for chemical identification. In some embodiments Raman analysis is conducted along with photoluminescence spectroscopy (i.e. fluorescence and/or phosphorescence spectroscopy) to provide high levels of sensitivity and specificity in the same instrument.

Optimal Background Attenuation for Fielded Spectroscopic Detection Systems

International Nuclear Information System (INIS)

Robinson, Sean M.; Ashbaker, Eric D.; Schweppe, John E.; Siciliano, Edward R.

2007-01-01

Radiation detectors are often placed in positions difficult to shield from the effects of terrestrial background gamma radiation. This is particularly true in the case of Radiation Portal Monitor (RPM) systems, as their wide viewing angle and outdoor installations make them susceptible to radiation from the surrounding area. Reducing this source of background can improve gross-count detection capabilities in the current generation of non-spectroscopic RPM's as well as source identification capabilities in the next generation of spectroscopic RPM's. To provide guidance for designing such systems, the problem of shielding a general spectroscopic-capable RPM system from terrestrial gamma radiation is considered. This analysis is carried out by template matching algorithms, to determine and isolate a set of non-threat isotopes typically present in the commerce stream. Various model detector and shielding scenarios are calculated using the Monte-Carlo N Particle (MCNP) computer code. Amounts of nominal-density shielding needed to increase the probability of detection for an ensemble of illicit sources are given. Common shielding solutions such as steel plating are evaluated based on the probability of detection for 3 particular illicit sources of interest, and the benefits are weighed against the incremental cost of shielding. Previous work has provided optimal shielding scenarios for RPMs based on gross-counting measurements, and those same solutions (shielding the internal detector cavity, direct shielding of the ground between the detectors, and the addition of collimators) are examined with respect to their utility to improving spectroscopic detection

Spectroscopic study of low-lying 16N levels

International Nuclear Information System (INIS)

Bardayan, Daniel W.; O'Malley, Patrick; Blackmon, Jeff C.; Chae, K.Y.; Chipps, K.; Cizewski, J.A.; Hatarik, Robert; Jones, K.L.; Kozub, R. L.; Matei, Catalin; Moazen, Brian; Nesaraja, Caroline D.; Pain, Steven D.; Paulauskas, Stanley; Peters, W.A.; Pittman, S.T.; Schmitt, Kyle; Shriner, J.F. Jr.; Smith, Michael Scott

2008-01-01

The magnitude of the 15N(n,gamma)16N reaction rate in asymptotic giant branch stars depends directly on the neutron spectroscopic factors of low-lying 16N levels. A new study of the 15N(d,p)16N reaction is reported populating the ground and first three excited states in 16N. The measured spectroscopic factors are near unity as expected from shell model calculations, resolving a long-standing discrepancy with earlier measurements that had never been confirmed or understood. Updated 15N(n,gamma)16N reaction rates are presented

Synthesis and spectroscopic characterization of a fluorescent pyrrole derivative containing electron acceptor and donor groups

Science.gov (United States)

Almeida, A. K. A.; Monteiro, M. P.; Dias, J. M. M.; Omena, L.; da Silva, A. J. C.; Tonholo, J.; Mortimer, R. J.; Navarro, M.; Jacinto, C.; Ribeiro, A. S.; de Oliveira, I. N.

2014-07-01

The synthesis and fluorescence characterization of a new pyrrole derivative (PyPDG) containing the electron donor-acceptor dansyl substituent is reported. The effects of temperature and solvent polarity on the steady-state fluorescence of this compound are investigated. Our results show that PyPDG exhibits desirable fluorescent properties which makes it a promising candidate to be used as the photoactive material in optical thermometry and thermography applications. Further, the electrochemical and emission properties of polymeric films obtained from the oxidation polymerization of PyPDG are also analyzed.

THE GALACTIC O-STAR SPECTROSCOPIC SURVEY (GOSSS). II. BRIGHT SOUTHERN STARS

International Nuclear Information System (INIS)

Sota, A.; Apellániz, J. Maíz; Alfaro, E. J.; Morrell, N. I.; Barbá, R. H.; Arias, J. I.; Walborn, N. R.; Gamen, R. C.

2014-01-01

We present the second installment of GOSSS, a massive spectroscopic survey of Galactic O stars, based on new homogeneous, high signal-to-noise ratio, R ∼ 2500 digital observations from both hemispheres selected from the Galactic O-Star Catalog (GOSC). In this paper we include bright stars and other objects drawn mostly from the first version of GOSC, all of them south of δ = –20°, for a total number of 258 O stars. We also revise the northern sample of Paper I to provide the full list of spectroscopically classified Galactic O stars complete to B = 8, bringing the total number of published GOSSS stars to 448. Extensive sequences of exceptional objects are given, including the early Of/WN, O Iafpe, Ofc, ON/OC, Onfp, Of?p, and Oe types, as well as double/triple-lined spectroscopic binaries. The new spectral subtype O9.2 is also discussed. The magnitude and spatial distributions of the observed sample are analyzed. We also present new results from OWN, a multi-epoch high-resolution spectroscopic survey coordinated with GOSSS that is assembling the largest sample of Galactic spectroscopic massive binaries ever attained. The OWN data combined with additional information on spectroscopic and visual binaries from the literature indicate that only a very small fraction (if any) of the stars with masses above 15-20 M ☉ are born as single systems. In the future we will publish the rest of the GOSSS survey, which is expected to include over 1000 Galactic O stars

Synthesis of polyimides from α,αʹ-bis(3-aminophenoxy)-p-xylene: Spectroscopic, single crystal XRD and thermal studies

Science.gov (United States)

Ashraf, Ahmad Raza; Akhter, Zareen; Simon, Leonardo C.; McKee, Vickie; Castel, Charles Dal

2018-05-01

The meta-catenated ether-based diamine monomer α,αʹ-bis(3-aminophenoxy)-p-xylene (3APX) was synthesized from dinitro precursor α,αʹ-bis(3-nitrophenoxy)-p-xylene (3NPX). FTIR, 1H and 13C NMR spectroscopic studies accompanied by elemental analysis were performed for structural elucidations of 3NPX and 3APX. The spatial orientations of 3APX were explored by single crystal X-ray diffraction analysis. Its crystal system was found to be monoclinic, adopting the space group P21/c. The synthesized diamine monomer (3APX) was used for preparation of new series of polyimides by reacting with three different dianhydrides (BTDA, ODPA, 6FDA). The relevant copolyimides were developed via incorporation of 4,4ʹ-methylenedianiline (MDA) in the backbone of afore-synthesized polyimides. The structures of polyimides and copolyimides were verified by FTIR and 1H NMR spectroscopic techniques. Their properties were evaluated by dynamic and isothermal TGA (nitrogen and air atmospheres) and WAXRD studies. Polyimides displayed significantly high thermal stability as their degradation started around 400 °C and it was improved further by execution of copolymerization strategy with MDA. The 5% weight loss temperature (T5) of polyimides under nitrogen atmosphere was in the range of 425-460 °C while for copolyimides it increased to 454-498 °C. Thermal decomposition in air was slower than nitrogen between 400 and 550 °C however it was accelerated above 550 °C. Isothermal TGA disclosed that copolyimides have the ability to endure elevated temperatures for extended period. WAXRD analysis showed the amorphous nature of polyimides and copolyimides.

Evolution of containment facilities for spectroscopic analysis at Rockwell Hanford Operations

International Nuclear Information System (INIS)

Hiller, J.M.

1984-01-01

The analysis of radioactive material requires much thought concerning getting the job done while still maintaining a safe working environment. A Rockwell Hanford Operations, several stages of evolution in instrumentation for spectroscopic elemental analysis have evolved, reflecting different philosophies respect to shielding and contamination control. Atomic absorption and inductively coupled plasma emission spectroscopic systems have been used for analyzing samples in support of a fission product recovery plant, nuclear waste processing and characterization programs, and U and Pu separation plants. Design thoughts, criticisms, and lessons learned in 20 years of containment for spectroscopic analysis are presented

Spectroscopic and electrical sensing mechanism in oxidant-mediated polypyrrole nanofibers/nanoparticles for ammonia gas

International Nuclear Information System (INIS)

Ishpal; Kaur, Amarjeet

2013-01-01

Ammonia gas sensing mechanism in oxidant-mediated polypyrrole (PPy) nanofibers/nanoparticles has been studied through spectroscopic and electrical investigations. PPy nanofibers/nanoparticles have been synthesized by chemical oxidation method in the presence of various oxidizing agents such as ammonium persulfate (APS), potassium persulfate (PPS), vanadium pentoxide (V 2 O 5 ), and iron chloride (FeCl 3 ). Scanning electron microscopy study revealed that PPy nanofibers of about 63, 71 and 79 nm diameters were formed in the presence of APS, PPS, V 2 O 5 , respectively, while PPy nanoparticles of about 100–110 nm size were obtained in the presence of FeCl 3 as an oxidant. The structural investigations and confirmation of synthesis of PPy were established through Fourier transform infrared and Raman spectroscopy. The gas sensing behavior of the prepared PPy samples is investigated by measuring the electrical resistance in ammonia environment. The observed gas sensing response (ΔR/Rx100) at 100 ppm level of ammonia is ∼4.5 and 18 % for the samples prepared with oxidizing agents FeCl 3 and APS, respectively, and by changing the ammonia level from 50 to 300 ppm, the sensing response varies from ∼4.5 to 11 % and ∼10 to 39 %, respectively. Out of all four samples, the PPy nanofibers prepared in the presence of APS have shown the best sensing response. The mechanism of gas sensing response of the PPy samples has been investigated through Raman spectroscopy study. The decrease of charge carrier concentration through reduction of polymeric chains has been recognized through Raman spectroscopic measurements recorded in ammonia environment.

The VANDELS ESO spectroscopic survey

Science.gov (United States)

McLure, R. J.; Pentericci, L.; Cimatti, A.; Dunlop, J. S.; Elbaz, D.; Fontana, A.; Nandra, K.; Amorin, R.; Bolzonella, M.; Bongiorno, A.; Carnall, A. C.; Castellano, M.; Cirasuolo, M.; Cucciati, O.; Cullen, F.; De Barros, S.; Finkelstein, S. L.; Fontanot, F.; Franzetti, P.; Fumana, M.; Gargiulo, A.; Garilli, B.; Guaita, L.; Hartley, W. G.; Iovino, A.; Jarvis, M. J.; Juneau, S.; Karman, W.; Maccagni, D.; Marchi, F.; Mármol-Queraltó, E.; Pompei, E.; Pozzetti, L.; Scodeggio, M.; Sommariva, V.; Talia, M.; Almaini, O.; Balestra, I.; Bardelli, S.; Bell, E. F.; Bourne, N.; Bowler, R. A. A.; Brusa, M.; Buitrago, F.; Caputi, K. I.; Cassata, P.; Charlot, S.; Citro, A.; Cresci, G.; Cristiani, S.; Curtis-Lake, E.; Dickinson, M.; Fazio, G. G.; Ferguson, H. C.; Fiore, F.; Franco, M.; Fynbo, J. P. U.; Galametz, A.; Georgakakis, A.; Giavalisco, M.; Grazian, A.; Hathi, N. P.; Jung, I.; Kim, S.; Koekemoer, A. M.; Khusanova, Y.; Le Fèvre, O.; Lotz, J. M.; Mannucci, F.; Maltby, D. T.; Matsuoka, K.; McLeod, D. J.; Mendez-Hernandez, H.; Mendez-Abreu, J.; Mignoli, M.; Moresco, M.; Mortlock, A.; Nonino, M.; Pannella, M.; Papovich, C.; Popesso, P.; Rosario, D. P.; Salvato, M.; Santini, P.; Schaerer, D.; Schreiber, C.; Stark, D. P.; Tasca, L. A. M.; Thomas, R.; Treu, T.; Vanzella, E.; Wild, V.; Williams, C. C.; Zamorani, G.; Zucca, E.

2018-05-01

VANDELS is a uniquely-deep spectroscopic survey of high-redshift galaxies with the VIMOS spectrograph on ESO's Very Large Telescope (VLT). The survey has obtained ultra-deep optical (0.48 studies. Using integration times calculated to produce an approximately constant signal-to-noise ratio (20 motivation, survey design and target selection.

Rare-earth metal compounds with a novel ligand 2-methoxycinnamylidenepyruvate: A thermal and spectroscopic approach

Energy Technology Data Exchange (ETDEWEB)

Carvalho, C.T., E-mail: claudiocarvalho@ufgd.edu.br [Federal University of Grande Dourados, UFGD, 79.804-970 Dourados, MS (Brazil); Oliveira, G.F. [Federal University of Grande Dourados, UFGD, 79.804-970 Dourados, MS (Brazil); Fernandes, J. [Federal University of Grande Dourados, UFGD, 79.804-970 Dourados, MS (Brazil); Federal University of Mato Grosso, UFMT, 78.060-900 Cuiabá, MT (Brazil); Federal University of Goiás, UFG, 74.690-900, Goiânia, GO (Brazil); Institute of Chemistry, UNESP, 14.801-970 Araraquara, SP (Brazil); Siqueira, A.B. [Federal University of Mato Grosso, UFMT, 78.060-900 Cuiabá, MT (Brazil); Ionashiro, E.Y. [Federal University of Goiás, UFG, 74.690-900, Goiânia, GO (Brazil); Ionashiro, M. [Institute of Chemistry, UNESP, 14.801-970 Araraquara, SP (Brazil)

2016-08-10

Highlights: • 2-Methoxycinnamylidenepyruvate as a novel ligand for the synthesis of complexes. • Complexes with well-defined structural arrangements. • Thermal decomposition dependent on the nature of the metal ion. • Study by TG/FT-IR and TG/MS of the gaseous products released. • Potential technological application. - Abstract: Compounds of 2-methoxycinnamylidenepyruvate with trivalent lanthanide ions (Tb, Ho, Er, Tm, Yb and Lu) were obtained in solid state and studied mainly in terms of their thermal and spectroscopic properties. The analyses of the characterization were performed by thermogravimetric system coupled to a mass and infrared spectrometer (TG–DTA/MS and TG–DTA/FT-IR), X-ray powder diffractometry, differential scanning calorimetry (DSC), infrared (FT-IR), preliminary study of fluorescence as well as classical technique of titration with EDTA. From these results, it was possible to establish the stoichiometry, thermal behavior, hydration water content, and the gaseous products released in the thermal decomposition steps, and suggest the type of metal-ligand coordination.

Synthesis and characterization of dihexyldithiocarbamate as a chelating agent in extraction of gold(III)

Energy Technology Data Exchange (ETDEWEB)

Fatimah, Soja Siti, E-mail: soja-sf@upi.edu [Departemen Pendidikan Kimia, Universitas Pendidikan Indonesia, Jl. Dr. Setiabudhi No. 229, Bandung 40154 (Indonesia); Department of Chemistry, Faculty of Mathematics and Natural Sciences, Padjadjaran University, Jl. Raya Bandung-Sumedang, Km. 21, Jatinangor (Indonesia); Bahti, Husein H.; Hastiawan, Iwan [Department of Chemistry, Faculty of Mathematics and Natural Sciences, Padjadjaran University, Jl. Raya Bandung-Sumedang, Km. 21, Jatinangor (Indonesia); Permanasari, Anna [Departemen Pendidikan Kimia, Universitas Pendidikan Indonesia, Jl. Dr. Setiabudhi No. 229, Bandung 40154 (Indonesia)

2016-02-08

The use of dialkyldithiocarbamates as chelating agents of transition metals have been developing for decades. Many chelating agents have been synthesized and used in the extraction of the metals. Studies on particular aspects of extraction of the metals, such as the effect of increasing hydrophobicity of chelating agents on the effectiveness of the extraction, have been done. However, despite the many studies on the synthesis and applications of this type of chelating agents, interests in the aspect of molecular structure of the synthesized ligands and of their complexes, have been limited. This study aimed at synthesizing and characterizing dihexylthiocarbamate, and using the ligand for the extraction of gold III). Characterization of the ligand and of its metal complex were done by using elemental analysis, DTG, and spectroscopic methods to include NMR, ({sup 1}H, and {sup 13}C), FTIR, and MS-ESI. Data on the synthesis, characterization, and the application of the ligand as a chelating agent are presented.

Synthesis and characterization of dihexyldithiocarbamate as a chelating agent in extraction of gold(III)

Science.gov (United States)

Fatimah, Soja Siti; Bahti, Husein H.; Hastiawan, Iwan; Permanasari, Anna

2016-02-01

The use of dialkyldithiocarbamates as chelating agents of transition metals have been developing for decades. Many chelating agents have been synthesized and used in the extraction of the metals. Studies on particular aspects of extraction of the metals, such as the effect of increasing hydrophobicity of chelating agents on the effectiveness of the extraction, have been done. However, despite the many studies on the synthesis and applications of this type of chelating agents, interests in the aspect of molecular structure of the synthesized ligands and of their complexes, have been limited. This study aimed at synthesizing and characterizing dihexylthiocarbamate, and using the ligand for the extraction of gold III). Characterization of the ligand and of its metal complex were done by using elemental analysis, DTG, and spectroscopic methods to include NMR, (1H, and 13C), FTIR, and MS-ESI. Data on the synthesis, characterization, and the application of the ligand as a chelating agent are presented.

The HITRAN 2008 molecular spectroscopic database

International Nuclear Information System (INIS)

Rothman, L.S.; Gordon, I.E.; Barbe, A.; Benner, D.Chris; Bernath, P.F.; Birk, M.; Boudon, V.; Brown, L.R.; Campargue, A.; Champion, J.-P.; Chance, K.; Coudert, L.H.; Dana, V.; Devi, V.M.; Fally, S.; Flaud, J.-M.

2009-01-01

This paper describes the status of the 2008 edition of the HITRAN molecular spectroscopic database. The new edition is the first official public release since the 2004 edition, although a number of crucial updates had been made available online since 2004. The HITRAN compilation consists of several components that serve as input for radiative-transfer calculation codes: individual line parameters for the microwave through visible spectra of molecules in the gas phase; absorption cross-sections for molecules having dense spectral features, i.e. spectra in which the individual lines are not resolved; individual line parameters and absorption cross-sections for bands in the ultraviolet; refractive indices of aerosols, tables and files of general properties associated with the database; and database management software. The line-by-line portion of the database contains spectroscopic parameters for 42 molecules including many of their isotopologues.

Mid-infrared spectroscopic investigation

International Nuclear Information System (INIS)

Walter, L.; Vergo, N.; Salisbury, J.W.

1987-01-01

Mid-infrared spectroscopic research efforts are discussed. The development of a new instrumentation to permit advanced measurements in the mid-infrared region of the spectrum, the development of a special library of well-characterized mineral and rock specimens for interpretation of remote sensing data, and cooperative measurements of the spectral signatures of analogues of materials that may be present on the surfaces of asteroids, planets or their Moons are discussed

synthesis, antimicrobial and phytotoxic activity of amide derivatives of L-(+)-2,3-diacetoxy-4-methoxy-4-oxo-butanoic acid

International Nuclear Information System (INIS)

Malik, M.; Khan, S.W.; Zaidi, J.H.; Khan, K.M.; Hussain, S.

2014-01-01

A short, versatile, an efficient asymmetric synthesis of substituted aromatic amides is described. L-Tartaric acid conveniently converted into diacetyl-L-tartaric anhydride. Diacetyl-L-tartaric anhydride was then transformed into half ester which was then reacted with substituted anilines to yield respective chiral amides 3-8. These chiral amides were characterized by spectroscopic techniques i.e. 1H-NMR, 13C-NMR, IR and mass spectrometry. Amides 3-8 were tested for their antimicrobial as well as phytotoxic activities. (author)

Chemical mapping of pharmaceutical cocrystals using terahertz spectroscopic imaging.

Science.gov (United States)

Charron, Danielle M; Ajito, Katsuhiro; Kim, Jae-Young; Ueno, Yuko

2013-02-19

Terahertz (THz) spectroscopic imaging is a promising technique for distinguishing pharmaceuticals of similar molecular composition but differing crystal structures. Physicochemical properties, for instance bioavailability, are manipulated by altering a drug's crystal structure through methods such as cocrystallization. Cocrystals are molecular complexes having crystal structures different from those of their pure components. A technique for identifying the two-dimensional distribution of these alternate forms is required. Here we present the first demonstration of THz spectroscopic imaging of cocrystals. THz spectra of caffeine-oxalic acid cocrystal measured at low temperature exhibit sharp peaks, enabling us to visualize the cocrystal distribution in nonuniform tablets. The cocrystal distribution was clearly identified using THz spectroscopic data, and the cocrystal concentration was calculated with 0.3-1.3% w/w error from the known total concentration. From this result, THz spectroscopy allows quantitative chemical mapping of cocrystals and offers researchers and drug developers a new analytical tool.

Spectroscopic methods for characterization of nuclear fuels

International Nuclear Information System (INIS)

Sastry, M.D.

1999-01-01

Spectroscopic techniques have contributed immensely in the characterisation and speciation of materials relevant to a variety of applications. These techniques have time tested credentials and continue to expand into newer areas. In the field of nuclear fuel fabrication, atomic spectroscopic methods are used for monitoring the trace metallic constituents in the starting materials and end product, and for monitoring process pick up. The current status of atomic spectroscopic methods for the determination of trace metallic constituents in nuclear fuel materials will be briefly reviewed and new approaches will be described with a special emphasis on inductively coupled plasma techniques and ETV-ICP-AES hyphenated techniques. Special emphasis will also be given in highlighting the importance of chemical separation procedures for the optimum utilization of potential of ICP. The presentation will also include newer techniques like Photo Acoustic Spectroscopy, and Electron Paramagnetic Resonance (EPR) Imaging. PAS results on uranium and plutonium oxides will be described with a reference to the determination of U 4+ /U 6+ concentration in U 3 O 8 . EPR imaging techniques for speciation and their spatial distribution in solids will be described and its potential use for Gd 3+ containing UO 2 pellets (used for flux flattening) will be highlighted. (author)

Synthesis of poly(aniline-co-o-toluidine) coatings on copper

Energy Technology Data Exchange (ETDEWEB)

Raotole, Pritee, E-mail: priteeraotole@gmail.com; Patil, V. T.; Huse, V. R.; Chaudhari, A. L. [MGSM’s Arts, Science and Commerce, College, Chopda, Dist-Jalgaon 425107, Maharashtra (India); Raotole, Mahesh [Sharacchandrika Suresh Patil, Institute of Technology, Polytechnic, Chopda, Dist-Jalgaon, 425107, Maharashtra (India)

2016-05-06

The corrosion protective poly(aniline-co-o-toluidine) (PAOT) coatings were synthesized on copper (Cu) by the electrochemical copolymerization of aniline with o-toluidine under cyclic voltammetry conditions. Aqueous oxalate solutions were used as the supporting electrolytes for the synthesis of PAOT coatings on Cu. The resulting coatings were characterized by different spectroscopic techniques, cyclic voltammetry, ultraviolet-visible absorption spectroscopy, Fourier transform infrared spectroscopy (FTIR), nuclear magnetic resonance spectroscopy (NMR), and scanning electron microscopy. The Fourier Transform InfraRed (FTIR) spectroscopy and Nuclear Magnetic Resonance (NMR) spectroscopy studies reveal that the copolymerization of aniline and o-toluidine takes place on Cu substrates from an aqueous oxalate solutions and resulting in PAOT copolymer, there are more o-toluidine units than aniline units.

Synthesis of palladium nanoparticles with leaf extract of Chrysophyllum cainito (Star apple) and their applications as efficient catalyst for C-C coupling and reduction reactions

Science.gov (United States)

Majumdar, Rakhi; Tantayanon, Supawan; Bag, Braja Gopal

2017-10-01

A simple green chemical method for the one-step synthesis of palladium nanoparticles (PdNPs) has been described by reducing palladium (II) chloride with the leaf extract of Chrysophyllum cainito in aqueous medium. The synthesis of the palladium nanoparticles completed within 2-3 h at room temperature, whereas on heat treatment (70-80 °C), the synthesis of colloidal PdNPs completed almost instantly. The stabilized PdNPs have been characterized in detail by spectroscopic, electron microscopic and light scattering measurements. The synthesized PdNPs have been utilized as a green catalyst for C-C coupling reactions under aerobic and phosphine-free conditions in aqueous medium. In addition, the synthesized PdNPs have also been utilized as a catalyst for a very efficient sodium borohydride reduction of 3- and 4-nitrophenols. The synthesized PdNPs can retain their catalytic activity for several months.

Evolution of containment facilities for spectroscopic analysis at Rockwell Hanford Operations

International Nuclear Information System (INIS)

Hiller, J.M.

1984-01-01

The analysis of radioactive material requires much thought concerning getting the job done while still maintaining a safe working environment. At Rockwell Hanford Operations, we have gone through several stages of evolution in instrumentation for spectroscopic elemental analysis, reflecting different philosophies with respect to shielding and contamination control. Atomic absorption and inductively coupled plasma emission spectroscopic systems have been used for analyzing samples in support of a fission product recovery plant, nuclear waste processing and characterization programs, and U and Pu separation plants. Design thoughts, criticisms, and lessons learned in 20 years of containment for spectroscopic analysis are presented. 3 refs., 6 figs., 2 tabs

Universal relation between spectroscopic constants

Indian Academy of Sciences (India)

(3) The author has used eq. (6) of his paper to calculate De. This relation leads to a large deviation from the correct value depending upon the extent to which experimental values are known. Guided by this fact, in our work, we used experimentally observed De values to derive the relation between spectroscopic constants.

Green Synthesis and Antibacterial Effect of Silver Nanoparticles Using Vitex Negundo L.

Directory of Open Access Journals (Sweden)

Fatima Abu Bakar

2011-08-01

Full Text Available Different biological methods are gaining recognition for the production of silver nanoparticles (Ag-NPs due to their multiple applications. One of the most important applications of Ag-NPs is their use as an anti-bacterial agent. The use of plants in the synthesis of nanoparticles emerges as a cost effective and eco-friendly approach. In this study the biosynthesis of silver nanoparticles using Vitex negundo L. extract and its antimicrobial properties has been reported. The resulting silver particles are characterized using transmission electron microscopy (TEM, X-ray diffraction (XRD and UV–Visible (UV-Vis spectroscopic techniques. The TEM study showed the formation of silver nanoparticles in the 10–30 nm range and average 18.2 nm in size. The XRD study showed that the particles are crystalline in nature, with a face centered cubic (fcc structure. The silver nanoparticles showed the antimicrobial activity against Gram positive and Gram negative bacteria. Vitex negundo L. was found to display strong potential for the synthesis of silver nanoparticles as antimicrobial agents by rapid reduction of silver ions (Ag+ to Ag0.

New approach in synthesis, characterization and release study of pH-sensitive polymeric micelles, based on PLA-Lys-b-PEGm, conjugated with doxorubicin

International Nuclear Information System (INIS)

Efthimiadou, E. K.; Tapeinos, C.; Bilalis, P.; Kordas, G.

2011-01-01

Amphiphilic block copolymers are well established as building blocks for the preparation of micellar drug carriers. The functional polymer micelles possess several advantages, such as high drug efficiency, targeted delivery, and minimized cytotoxicity. The synthesis of block copolymers using nano-structured templates has emerged as a useful and versatile approach for preparing drug carriers. Here, we report the synthesis of a smart polymeric compound of a diblock PLA-Lys-b-PEG copolymer containing doxorubicin. We have synthesized functionalized diblock copolymers, with lysinol, poly(lactide) and monomethoxy poly(ethylene glycol) via thermal ring-opening polymerization and a subsequent six-step substitution reaction. A variety of spectroscopic methods were employed here to verify the product of our synthesis. 1 H-Nuclear magnetic resonance and Fourier transform infrared studies validated the expected synthesis of copolymers. Doxorubicin is chemically loaded into micelles, and the ex vitro release can be evaluated either in weak acidic or in SBF solution by UV–vis spectroscopy. Dynamic light scattering, thermo gravimetric analysis, and size exclusion chromatography have also been used.

Bio-medical X-ray imaging with spectroscopic pixel detectors

CERN Document Server

Butler, A P H; Tipples, R; Cook, N; Watts, R; Meyer, J; Bell, A J; Melzer, T R; Butler, P H

2008-01-01

The aim of this study is to review the clinical potential of spectroscopic X-ray detectors and to undertake a feasibility study using a novel detector in a clinical hospital setting. Detectors currently in development, such as Medipix-3, will have multiple energy thresholds allowing for routine use of spectroscopic bio-medical imaging. We have coined the term MARS (Medipix All Resolution System) for bio-medical images that provide spatial, temporal, and energy information. The full clinical significance of spectroscopic X-ray imaging is difficult to predict but insights can be gained by examining both image reconstruction artifacts and the current uses of dual-energy techniques. This paper reviews the known uses of energy information in vascular imaging and mammography, clinically important fields. It then presents initial results from using Medipix-2, to image human tissues within a clinical radiology department. Detectors currently in development, such as Medipix-3, will have multiple energy thresholds allo...

Very large area multiwire spectroscopic proportional counters

International Nuclear Information System (INIS)

Ubertini, P.; Bazzano, A.; Boccaccini, L.; Mastropietro, M.; La Padula, C.D.; Patriarca, R.; Polcaro, V.F.

1981-01-01

As a result of a five year development program, a final prototype of a Very Large Area Spectroscopic Proportional Counter (VLASPC), to be employed in space borne payloads, was produced at the Istituto di Astrofisica Spaziale, Frascati. The instrument is the last version of a new generation of Multiwire Spectroscopic Proportional Counters (MWSPC) succesfully employed in many balloon borne flights, devoted to hard X-ray astronomy. The sensitive area of this standard unit is 2700 cm 2 with an efficiency higher than 10% in the range 15-180 keV (80% at 60 keV). The low cost and weight make this new type of VLASPC competitive with Nal arrays, phoswich and GSPC detectors in terms of achievable scientific results. (orig.)

Very large area multiwire spectroscopic proportional counters

Energy Technology Data Exchange (ETDEWEB)

Ubertini, P.; Bazzano, A.; Boccaccini, L.; Mastropietro, M.; La Padula, C.D.; Patriarca, R.; Polcaro, V.F. (Istituto di Astrofisica Spaziale, Frascati (Italy))

1981-07-01

As a result of a five year development program, a final prototype of a Very Large Area Spectroscopic Proportional Counter (VLASPC), to be employed in space borne payloads, was produced at the Istituto di Astrofisica Spaziale, Frascati. The instrument is the last version of a new generation of Multiwire Spectroscopic Proportional Counters (MWSPC) successfully employed in many balloon borne flights, devoted to hard X-ray astronomy. The sensitive area of this standard unit is 2700 cm/sup 2/ with an efficiency higher than 10% in the range 15-180 keV (80% at 60 keV). The low cost and weight make this new type of VLASPC competitive with Nal arrays, phoswich and GSPC detectors in terms of achievable scientific results.

Toxicological methods for tracing drug abuse: chromatographic, spectroscopic and biological characterisation of ecstasy derivatives.

Science.gov (United States)

Belhadj-Tahar, Hafid; Payoux, Pierre; Tafani, Mathieu; Coulais, Yvon; Calet, Serge; Bousseksou, Azzedine

2010-03-01

Analysis often reveals variability in the composition of ecstasy pills from pure 3,4-methylenedioxymethamphetamine (MDMA) to mixtures of MDMA derivatives, amphetamine, and other unidentified substances. For a comprehensive toxicological analysis one needs to know all steps to MDMA synthesis which may originate impurities. The aim of this study was to synthesise and determine the chemical-physical and in vitro biological properties of a series of MDMA derivatives.3,4-methylendioxyphenyl-2-nitropropene (MDNP) was obtained by condensation of piperonal with an excess of nitroethane in the presence of ammonium acetate. MDNP was then reduced to methylenedioxyamphetamine (MDA) by LiAlH3. All compounds were analysed using HPLC and spectroscopic technique [Raman, nuclear magnetic resonance (NMR), or infrared (IR)] at all the steps of synthesis. In addition, we assessed the biological potentials of these compounds by measuring in vitro their (i) blood cell/whole blood partition coefficient, (ii) binding to plasmatic proteins (Fbp), and (iii) membrane adsorption. Chemical structure was determined with antibody fluorescence polarisation immunoassay (FPIA). This study showed the presence of solid impurities, particularly of a neurotoxic compound of Al3+ in the final products. FPIA identified the aminoethane group close to the substituted benzene ring, but did not detect the two major precursors of MDMA: MDNP and piperonal. Raman spectroscopy is an attractive alternative technique to characterise ecstasy pills and it can identify stereoisomeric forms such as cis-MDNP and trans-MDNP, which exhibit signals at 1650 cm-1 and 1300 cm-1, respectively.

A spectroscopic census in young stellar regions: the σ Orionis cluster

Energy Technology Data Exchange (ETDEWEB)

Hernández, Jesús; Perez, Alice; Hernan, Ramírez [Centro de Investigaciones de Astronomía, Apdo. Postal 264, Mérida 5101-A (Venezuela, Bolivarian Republic of); Calvet, Nuria; Hartmann, Lee [Department of Astronomy, University of Michigan, 500 Church Street, Ann Arbor, MI 48109 (United States); Briceño, Cesar [Cerro Tololo Interamerican Observatory, Casilla 603, La Serena (Chile); Olguin, Lorenzo [Depto. de Investigación en Física, Universidad de Sonora, Sonora (Mexico); Contreras, Maria E. [Instituto de Astronomía, Universidad Nacional Autónoma de México, Ensenada, BC (Mexico); Allen, Lori [National Optical Astronomy Observatory, 950 North Cherry Avenue, Tucson, AZ 85719 (United States); Espaillat, Catherine, E-mail: hernandj@cida.ve [Department of Astronomy, Boston University, 725 Commonwealth Avenue, Boston, MA 02215 (United States)

2014-10-10

We present a spectroscopic survey of the stellar population of the σ Orionis cluster. We have obtained spectral types for 340 stars. Spectroscopic data for spectral typing come from several spectrographs with similar spectroscopic coverage and resolution. More than half of the stars in our sample are members confirmed by the presence of lithium in absorption, strong Hα in emission or weak gravity-sensitive features. In addition, we have obtained high-resolution (R ∼ 34,000) spectra in the Hα region for 169 stars in the region. Radial velocities were calculated from this data set. The radial velocity distribution for members of the cluster is in agreement with previous work. Analysis of the profile of the Hα line and infrared observations reveals two binary systems or fast rotators that mimic the Hα width expected in stars with accretion disks. On the other hand, there are stars with optically thick disks and narrow Hα profiles not expected in stars with accretion disks. This contribution constitutes the largest homogeneous spectroscopic data set of the σ Orionis cluster to date.

QUANTIFYING THE BIASES OF SPECTROSCOPICALLY SELECTED GRAVITATIONAL LENSES

International Nuclear Information System (INIS)

Arneson, Ryan A.; Brownstein, Joel R.; Bolton, Adam S.

2012-01-01

Spectroscopic selection has been the most productive technique for the selection of galaxy-scale strong gravitational lens systems with known redshifts. Statistically significant samples of strong lenses provide a powerful method for measuring the mass-density parameters of the lensing population, but results can only be generalized to the parent population if the lensing selection biases are sufficiently understood. We perform controlled Monte Carlo simulations of spectroscopic lens surveys in order to quantify the bias of lenses relative to parent galaxies in velocity dispersion, mass axis ratio, and mass-density profile. For parameters typical of the SLACS and BELLS surveys, we find (1) no significant mass axis ratio detection bias of lenses relative to parent galaxies; (2) a very small detection bias toward shallow mass-density profiles, which is likely negligible compared to other sources of uncertainty in this parameter; (3) a detection bias toward smaller Einstein radius for systems drawn from parent populations with group- and cluster-scale lensing masses; and (4) a lens-modeling bias toward larger velocity dispersions for systems drawn from parent samples with sub-arcsecond mean Einstein radii. This last finding indicates that the incorporation of velocity-dispersion upper limits of non-lenses is an important ingredient for unbiased analyses of spectroscopically selected lens samples. In general, we find that the completeness of spectroscopic lens surveys in the plane of Einstein radius and mass-density profile power-law index is quite uniform, up to a sharp drop in the region of large Einstein radius and steep mass-density profile, and hence that such surveys are ideally suited to the study of massive field galaxies.

A SARS-coronovirus 3CL protease inhibitor isolated from the marine sponge Axinella cf. corrugata: structure elucidation and synthesis

International Nuclear Information System (INIS)

Lira, Simone P. de; Seleghim, Mirna H.R.; Berlinck, Roberto G.S.

2007-01-01

Two coumarin derivatives, esculetin-4-carboxylic acid methyl ester (1) and esculetin-4- carboxylic acid ethyl ester (2), have been isolated from the marine sponge Axinella cf. corrugata. Structure determination included analysis of spectroscopic data and total synthesis of compound 2. These are the first coumarin derivatives isolated from a marine sponge. The ethyl ester 2 was found to be an in vitro inhibitor of SARS 3CL-protease and an effective inhibitor of SARS-CoV replication in Vero cells at non-cytotoxic concentrations. (author)

SYNTHESIS, SPECTROSCOPIC CHARACTERIZATION AND ...

African Journals Online (AJOL)

userpc

ABSTRACT. A tridendatate Schiff base,L, 2-((2-hydroxynaphthalen-1-yl) methyleneamino)benzoic acid was prepared by condensation of 2-aminobenzoic acid with 2-hydroxy-1-naphthaldehyde.The prepared ligand was used to synthesize Sm(III) and Dy(III) complexes [LnL(NO3)2]NO3.2H2O,. (Ln=Sm(III) and Dy(III)).

Technical report for fabrication and performance test of electrochemical/spectroscopic measurement system

International Nuclear Information System (INIS)

Park, Yong Joon; Cho, Young Hwan; Bae, Sang Eun; Im, Hee Jung; Song, Kyu Seok

2010-01-01

Development of evaluation technology of electrochemical reactions is very essential to understand chemical behavior of actinides and lanthanides in molten salt media in relation to the development of Pyrochemical process. The on-line electrochemical/spectroscopic measurement system is to produce electrochemical parameters and thermodynamic parameters of actinides and lanthanides in molten salts by using spectroscopic techniques such as UV-VIS absorption as well as electrochemical in-situ measurement techniques. The on-line electrochemical/spectroscopic measurement system can be applied to understand the chemical reactions and oxidation states of actinides and lanthanides in molten salts eventually for the Pyrochemical process

Synthesis, characterization, photophysical, and photochemical properties of novel zinc(II) and indium(III) phthalocyanines containing 2-phenylphenoxy units

Energy Technology Data Exchange (ETDEWEB)

Ali, Haytham Elzien Alamin [Department of Chemistry, Marmara University, Istanbul 34722 (Turkey); University of Khartoum, Department of Chemistry, Faculty of Science, P.O. Box 321, Khartoum, 11115 (Sudan); Pişkin, Mehmet [Çanakkale Onsekiz Mart University, Vocational School of Technical Sciences, Department of Food Technology, Çanakkale 17100 (Turkey); Altun, Selçuk [Department of Chemistry, Marmara University, Istanbul 34722 (Turkey); Durmuş, Mahmut [Gebze Technical University, Department of Chemistry, P.O. Box 141, Gebze, Kocaeli 41400 (Turkey); Odabaş, Zafer, E-mail: zodabas@marmara.edu.tr [Department of Chemistry, Marmara University, Istanbul 34722 (Turkey)

2016-05-15

The synthesis of highly soluble and non-aggregated peripherally/non-peripherally Zn and In(OAc) phthalocyanines was achieved by 3-/ and 4-(2-phenylphenoxy)phthalonitrile as starting materials. The novel compounds were characterized by elemental analyses, FT-IR, {sup 1}H-NMR (for phthalonitriles), UV–vis and MALDI-TOF mass (for Pcs) spectroscopic techniques. Additionally, photophysical, photochemical and spectral properties of the phthalocyanines were reported. Especially, the indium(OAc) phthalocyanines showed good singlet oxygen quantum yields in DMSO and they can be appropriate candidates as Type II photosensitizers in photodynamic therapy (PDT) applications.

Synthesis, characterization, photophysical, and photochemical properties of novel zinc(II) and indium(III) phthalocyanines containing 2-phenylphenoxy units

International Nuclear Information System (INIS)

Ali, Haytham Elzien Alamin; Pişkin, Mehmet; Altun, Selçuk; Durmuş, Mahmut; Odabaş, Zafer

2016-01-01

The synthesis of highly soluble and non-aggregated peripherally/non-peripherally Zn and In(OAc) phthalocyanines was achieved by 3-/ and 4-(2-phenylphenoxy)phthalonitrile as starting materials. The novel compounds were characterized by elemental analyses, FT-IR, 1 H-NMR (for phthalonitriles), UV–vis and MALDI-TOF mass (for Pcs) spectroscopic techniques. Additionally, photophysical, photochemical and spectral properties of the phthalocyanines were reported. Especially, the indium(OAc) phthalocyanines showed good singlet oxygen quantum yields in DMSO and they can be appropriate candidates as Type II photosensitizers in photodynamic therapy (PDT) applications.

Synthesis, characterization and spectroscopic properties of a new Nd{sup 3+}-doped Co-picromerite-type Tutton salt

Energy Technology Data Exchange (ETDEWEB)

Souamti, A., E-mail: souamtiahmed88@gmail.com [Laboratoire d' Application de la Chimie aux Ressources et Substances Naturelles et à l' Environnement, Département de Chimie, Université de Carthage, Faculté des Sciences de Bizerte, Zarzouna, Bizerte 7021 (Tunisia); Martín, I.R. [Departamento de Física, Universidad de La Laguna, 38206 La Laguna (Spain); Zayani, L. [Laboratoire d' Application de la Chimie aux Ressources et Substances Naturelles et à l' Environnement, Département de Chimie, Université de Carthage, Faculté des Sciences de Bizerte, Zarzouna, Bizerte 7021 (Tunisia); Hernández-Rodríguez, M.A.; Soler-Carracedo, K.; Lozano-Gorrín, A.D. [Departamento de Física, Universidad de La Laguna, 38206 La Laguna (Spain); Lalla, E. [Extreme Light Infrastructure – Nuclear Physics (ELI-NP), Horia Hulubei, National Institute of Physics and Nuclear Engineering (IFIN HH), 30, Reactorului Street, P.O. Box MG-6, 077125 Magurele, jud. Ilfov (Romania); Chehimi, D. Ben Hassen [Laboratoire d' Application de la Chimie aux Ressources et Substances Naturelles et à l' Environnement, Département de Chimie, Université de Carthage, Faculté des Sciences de Bizerte, Zarzouna, Bizerte 7021 (Tunisia)

2016-09-15

Single crystals of Nd{sup 3+}-doped Co-picromerite has been synthesized by the slow evaporation method. After two weeks on hold, the crystals obtained were characterized by different techniques, indeed X-ray powder diffraction (XRPD) shows that these compounds crystallize in the monoclinic system with space group P21/a. Complete dehydration of the double salt was obtained before reaching 200 °C with a phase transition of KS around 570 °C. The IR spectroscopic study confirms the vibrational modes of the sulfate groups and water molecules. Exciting at 473 nm, the emission peaks associated with the 4F{sub 5/2}→4I{sub 9/2}, 4F{sub 3/2}→4I{sub 9/2} and 4F{sub 3/2}→4I{sub 11/2} transitions were observed. The luminescence decay curve was analyzed in the frame of the Inokuti-Hirayama model in order to obtain the intrinsic lifetime and the energy transfer parameter among Nd{sup 3+}ions.

Synthesis and characterization of a new porphyrin-polyoxometalate hybrid material and investigation of its catalytic activity.

Science.gov (United States)

Araghi, Mehdi; Mirkhani, Valiollah; Moghadam, Majid; Tangestaninejad, Shahram; Mohammdpoor-Baltork, Iraj

2012-03-14

In the present work, the preparation of a new organic-inorganic hybrid material in which tetrakis(p-aminophenylporphyrin) is covalently linked to a Lindqvist structure of polyoxometalate, is reported. This new porphyrin-polyoxometalate hybrid material was characterized by (1)H NMR, FT-IR and UV-Vis spectroscopic methods and cyclic voltammetry. These spectro- and electrochemical studies provided spectral data of the synthesis of this compound. Cyclic voltammetry showed the influence of the porphyrin on the redox process of the polyoxometalate. The catalytic activity of this hybrid material was investigated in the alkene epoxidation with NaIO(4).

Synthesis and characterization of polypyrrole doped with anionic spherical polyelectrolyte brushes

Directory of Open Access Journals (Sweden)

N. Su

2012-09-01

Full Text Available The procedures for the synthesis of polypyrrole (PPy doped with anionic spherical polyelectrolyte brushes (ASPB (PPy/ASPB nanocomposite by means of in situ chemical oxidative polymerization were presented. Fourier transform infrared spectroscopy (FTIR and Raman spectroscopic analysis suggested the bonding structure of PPy/ASPB nanocomposite. Scanning electron microscopy (SEM was used to confirm the morphologies of samples. The crystallographic structure, chemical nature and thermal stability of conducting polymers were analyzed by X-ray diffraction (XRD, X-ray photoelectron spectroscopy (XPS and Thermo-gravimetric analysis (TGA respectively. Investigation of the electrical conductivity at room temperature showed that the electrical conductivity of PPy/ASPB nanocomposite was 20 S/cm, which was higher than that of PPy (3.6 S/cm.

The HITRAN2016 molecular spectroscopic database

Energy Technology Data Exchange (ETDEWEB)

Gordon, I. E.; Rothman, L. S.; Hill, C.; Kochanov, R. V.; Tan, Y.; Bernath, P. F.; Birk, M.; Boudon, V.; Campargue, A.; Chance, K. V.; Drouin, B. J.; Flaud, J. -M.; Gamache, R. R.; Hodges, J. T.; Jacquemart, D.; Perevalov, V. I.; Perrin, A.; Shine, K. P.; Smith, M. -A. H.; Tennyson, J.; Toon, G. C.; Tran, H.; Tyuterev, V. G.; Barbe, A.; Császár, A. G.; Devi, V. M.; Furtenbacher, T.; Harrison, J. J.; Hartmann, J. -M.; Jolly, A.; Johnson, T. J.; Karman, T.; Kleiner, I.; Kyuberis, A. A.; Loos, J.; Lyulin, O. M.; Massie, S. T.; Mikhailenko, S. N.; Moazzen-Ahmadi, N.; Müller, H. S. P.; Naumenko, O. V.; Nikitin, A. V.; Polyansky, O. L.; Rey, M.; Rotger, M.; Sharpe, S. W.; Sung, K.; Starikova, E.; Tashkun, S. A.; Auwera, J. Vander; Wagner, G.; Wilzewski, J.; Wcisło, P.; Yu, S.; Zak, E. J.

2017-12-01

This paper describes the contents of the 2016 edition of the HITRAN molecular spectroscopic compilation. The new edition replaces the previous HITRAN edition of 2012 and its updates during the intervening years. The HITRAN molecular absorption compilation is comprised of five major components: the traditional line-by-line spectroscopic parameters required for high-resolution radiative-transfer codes, infrared absorption cross-sections for molecules not yet amenable to representation in a line-by-line form, collision-induced absorption data, aerosol indices of refraction, and general tables such as partition sums that apply globally to the data. The new HITRAN is greatly extended in terms of accuracy, spectral coverage, additional absorption phenomena, added line-shape formalisms, and validity. Moreover, molecules, isotopologues, and perturbing gases have been added that address the issues of atmospheres beyond the Earth. Of considerable note, experimental IR cross-sections for almost 200 additional significant molecules have been added to the database.

Theoretical studies on CH+ ion molecule using configuration interaction method and its spectroscopic properties

International Nuclear Information System (INIS)

Machado, F.B.C.

1985-01-01

The use of the configuration (CI) method for the calculation of very accurate potential energy curves and dipole moment functions, and then their use in the comprehension of spectroscopic properties of diatomic molecules is presented. The spectroscopic properties of CH + and CD + such as: vibrational levels, spectroscopic constants, averaged dipole moments for all vibrational levels, radiative transition probabilities for emission and absorption, and radiative lifetimes are verificated. (M.J.C.) [pt

Curcumin: Synthesis optimization and in silico interaction with cyclin dependent kinase.

Science.gov (United States)

Ahmed, Mahmood; Abdul Qadir, Muhammad; Imtiaz Shafiq, Muhammad; Muddassar, Muhammad; Hameed, Abdul; Nadeem Arshad, Muhammad; Asiri, Abdullah M

2017-09-01

Curcumin is a natural product with enormous biological potential. In this study, curcumin synthesis was revisited using different reaction solvents, a catalyst (n-butylamine) and a water scavenger [(n-BuO)3B], to develop the optimal procedure for its rapid acquisition. During synthesis, solvent choice was found to be an important parameter for better curcumin yield and high purity. In a typical reaction, acetyl acetone was treated with boron trioxide, followed by condensation with vanillin in the presence of tri-n-butyl borate as water scavenger and n-butylamine as catalyst at 80 °C in ethyl acetate to afford curcumin. Moreover, curcumin was also extracted from turmeric powder and spectroscopic properties such as IR, MS, 1H NMR and 13C NMR with synthetic curcumin were established to identify any impurity. The purity of synthetic and extracted curcumin was also checked by TLC and HPLC-DAD. To computationally assess its therapeutic potential against cyclin dependent kinases (CDKs), curcumin was docked in different isoforms of CDKs. It was observed that it did not dock at the active sites of CDK2 and CDK6. However, it could enter into weak interactions with CDK4 protein.

Biogenic synthesis of silver nanoparticles by leaf extract of Cassia angustifolia

Science.gov (United States)

Amaladhas, T. Peter; Sivagami, S.; Akkini Devi, T.; Ananthi, N.; Priya Velammal, S.

2012-12-01

In this study Cassia angustifolia (senna) is used for the environmentally friendly synthesis of silver nanoparticles. Stable silver nanoparticles having symmetric surface plasmon resonance (SPR) band centred at 420 nm were obtained within 10 min at room temperature by treating aqueous solutions of silver nitrate with C. angustifolia leaf extract. The water soluble components from the leaves, probably the sennosides, served as both reducing and capping agents in the synthesis of silver nanoparticles. The nanoparticles were characterized using UV-Vis, Fourier transform infrared (FTIR) spectroscopic techniques and transmission electron microscopy (TEM). The nanoparticles were poly-dispersed, spherical in shape with particle size in the range 9-31 nm, the average size was found to be 21.6 nm at pH 11. The zeta potential was -36.4 mV and the particles were stable for 6 months. The crystalline phase of the nanoparticles was confirmed from the selected area diffraction pattern (SAED). The rate of formation and size of silver nanoparticles were pH dependent. Functional groups responsible for capping of silver nanoparticles were identified from the FTIR spectrum. The synthesized silver nanoparticles exhibited good antibacterial potential against Escherichia coli and Staphylococcus aureus.

Biogenic synthesis of silver nanoparticles by leaf extract of Cassia angustifolia

International Nuclear Information System (INIS)

Peter Amaladhas, T; Akkini Devi, T; Ananthi, N; Priya Velammal, S; Sivagami, S

2012-01-01

In this study Cassia angustifolia (senna) is used for the environmentally friendly synthesis of silver nanoparticles. Stable silver nanoparticles having symmetric surface plasmon resonance (SPR) band centred at 420 nm were obtained within 10 min at room temperature by treating aqueous solutions of silver nitrate with C. angustifolia leaf extract. The water soluble components from the leaves, probably the sennosides, served as both reducing and capping agents in the synthesis of silver nanoparticles. The nanoparticles were characterized using UV–Vis, Fourier transform infrared (FTIR) spectroscopic techniques and transmission electron microscopy (TEM). The nanoparticles were poly-dispersed, spherical in shape with particle size in the range 9–31 nm, the average size was found to be 21.6 nm at pH 11. The zeta potential was –36.4 mV and the particles were stable for 6 months. The crystalline phase of the nanoparticles was confirmed from the selected area diffraction pattern (SAED). The rate of formation and size of silver nanoparticles were pH dependent. Functional groups responsible for capping of silver nanoparticles were identified from the FTIR spectrum. The synthesized silver nanoparticles exhibited good antibacterial potential against Escherichia coli and Staphylococcus aureus. (paper)

The Gaia-ESO Public Spectroscopic Survey

DEFF Research Database (Denmark)

Gilmore, G.; Randich, S.; Asplund, M.

2012-01-01

The Gaia-ESO Public Spectroscopic Survey has begun and will obtain high quality spectroscopy of some 100000 Milky Way stars, in the field and in open clusters, down to magnitude 19, systematically covering all the major components of the Milky Way. This survey will provide the first homogeneous o...

Highlights of the Brazilian Solar Spectroscope

Czech Academy of Sciences Publication Activity Database

Sawant, H. S.; Cecatto, J.R.; Mészárosová, Hana; Faria, C.; Fernandes, F. C. R.; Karlický, Marian; de Andrade, M. C.

2009-01-01

Roč. 44, č. 1 (2009), s. 54-57 ISSN 0273-1177 R&D Projects: GA AV ČR IAA300030701 Institutional research plan: CEZ:AV0Z10030501 Keywords : Sun istrumentation * spectroscope * corona * radio radiation Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics Impact factor: 1.079, year: 2009

Low-dimensional compounds containing cyano groups. XVII. Crystal structure, spectroscopic, thermal and magnetic properties of [Cu(bmen)2][Pt(CN)4] (bmen=N,N'-dimethylethylenediamine)

International Nuclear Information System (INIS)

Potocnak, Ivan; Vavra, Martin; Cizmar, Erik; Kajnakova, Marcela; Radvakova, Alena; Steinborn, Dirk; Zvyagin, Sergei A.; Wosnitza, Jochen; Feher, Alexander

2009-01-01

The synthesis, structural analysis, spectroscopic studies, susceptibility and specific-heat measurements of {[Cu(bmen) 2 ][Pt(CN) 4 ]} n (bmen=N,N'-dimethylethylenediamine) are presented. X-ray crystal-structure analysis revealed that the [Pt(CN) 4 ] 2- building blocks are combined with [Cu(bmen) 2 ] 2+ units to form a chain-like structure along the a axis. The Cu(II) atoms are hexacoordinated by four nitrogen atoms in the equatorial plane belonging to two molecules of bidentate bmen ligands with average Cu-N distance of 2.043(18) A. The axial positions are occupied by two nitrogen atoms from bridging [Pt(CN) 4 ] 2- anions at a longer axial Cu-N distance of 2.490(4) A. The compound is characterized by the presence of a weak antiferromagnetic exchange coupling J/k B =0.6 K. Despite the one-dimensional (1D) character of the structure, the analysis of the magnetic properties and specific heat at very low temperatures shows that [Cu(bmen) 2 ][Pt(CN) 4 ] behaves as a two-dimensional (2D) square-lattice Heisenberg magnet with weak interlayer coupling. - Graphical abstract: The synthesis, structural analysis, spectroscopic studies, susceptibility and specific-heat measurements of {[Cu(bmen) 2 ][Pt(CN) 4 ]} n (bmen=N,N'-dimethylethylenediamine) are presented. X-ray crystal-structure analysis revealed that the [Pt(CN) 4 ] 2- building blocks are combined with [Cu(bmen) 2 ] 2+ units to form a chain-like structure. The compound is characterized by the presence of a weak antiferromagnetic exchange coupling J/k B =-0.6 K. Despite the one-dimensional character of the structure, the analysis of the magnetic properties and specific heat at very low temperatures shows that [Cu(bmen) 2 ][Pt(CN) 4 ] behaves as a two-dimensional square-lattice Heisenberg magnet with weak interlayer coupling

[Spectroscopic characteristics of novel Psidium meroterpenoids isolated from guava leaves].

Science.gov (United States)

Ouyang, Wen; Zhu, Xiao-ai; Liu, Xiao-juan; Yie, Shu-min; Zhao, Litchao; Su, Lei; Cao, Yong

2015-07-01

Recently, novel Psidium meroterpenoids were reported in the guava leaves. According to careful analysis of the spectral data of literatures, the spectroscopic characteristics and biosynthetic pathway of Psidium meroterpenoids were summarized in this paper. The results showed that Psidium meroterpenoids had distinct spectroscopic features and reasonable biosynthetic routines, however the number order of carbon atoms was not consistent in the reported literatures. It was concluded that Psidium meroterpenoids were the characteristic chemical constituents of Psidium guajava Linn.

Fuel cells: spectroscopic studies in the electrocatalysis of alcohol oxidation

OpenAIRE

Iwasita Teresa

2002-01-01

Modern spectroscopic methods are useful for elucidating complex electrochemical mechanisms as those occurring during the oxidation of small organic molecules (CH3OH, HCOH, HCOOH). In the present paper it is shown the use of spectroscopic methods to study the oxidation of alcohols on platinum or Pt-based binary electrodes. These reactions are of importance in conexion with the development of anode systems for use in fuel cells. Mass spectrometry and FT infrared spectroscopy allow to establishi...

Identification and Spectroscopic Characterization of Nonheme Iron(III) Hypochlorite Intermediates**

Science.gov (United States)

Draksharapu, Apparao; Angelone, Davide; Quesne, Matthew G; Padamati, Sandeep K; Gómez, Laura; Hage, Ronald; Costas, Miquel; Browne, Wesley R; de Visser, Sam P

2015-01-01

FeIII–hypohalite complexes have been implicated in a wide range of important enzyme-catalyzed halogenation reactions including the biosynthesis of natural products and antibiotics and post-translational modification of proteins. The absence of spectroscopic data on such species precludes their identification. Herein, we report the generation and spectroscopic characterization of nonheme FeIII–hypohalite intermediates of possible relevance to iron halogenases. We show that FeIII-OCl polypyridylamine complexes can be sufficiently stable at room temperature to be characterized by UV/Vis absorption, resonance Raman and EPR spectroscopies, and cryo-ESIMS. DFT methods rationalize the pathways to the formation of the FeIII-OCl, and ultimately FeIV=O, species and provide indirect evidence for a short-lived FeII-OCl intermediate. The species observed and the pathways involved offer insight into and, importantly, a spectroscopic database for the investigation of iron halogenases. PMID:25663379

Spectroscopically Enhanced Method and System for Multi-Factor Biometric Authentication

Science.gov (United States)

Pishva, Davar

This paper proposes a spectroscopic method and system for preventing spoofing of biometric authentication. One of its focus is to enhance biometrics authentication with a spectroscopic method in a multifactor manner such that a person's unique ‘spectral signatures’ or ‘spectral factors’ are recorded and compared in addition to a non-spectroscopic biometric signature to reduce the likelihood of imposter getting authenticated. By using the ‘spectral factors’ extracted from reflectance spectra of real fingers and employing cluster analysis, it shows how the authentic fingerprint image presented by a real finger can be distinguished from an authentic fingerprint image embossed on an artificial finger, or molded on a fingertip cover worn by an imposter. This paper also shows how to augment two widely used biometrics systems (fingerprint and iris recognition devices) with spectral biometrics capabilities in a practical manner and without creating much overhead or inconveniencing their users.

Thermodynamic-Controlled Gas Phase Process for the Synthesis of Nickel Nanoparticles of Adjustable Size and Morphology

International Nuclear Information System (INIS)

Kauffeldt, Elena; Kauffeldt, Thomas

2006-01-01

Gas phase processes are a successful route for the synthesis of nano materials. Nickel particles are used in applications ranging from catalysis to nano electronics and energy storage. The application field defines the required particle size, morphology, crystallinity and purity. Nickel tetracarbonyl is the most promising precursor for the synthesis of high purity nickel particles. Due to the toxicity of this precursor and to obtain an optimal process control we developed a two-step flow type process. Nickel carbonyl and nickel particles are synthesized in a sequence of reactions. The particles are formed in a hot wall reactor at temperatures below 400 deg. C in different gas compositions. Varying the process conditions enables the adjustment of the particle size in a range from 3 to 140 nm. The controllable crystalline habits are polycrystalline, single crystals or multiple twinned particles (MTP). Spectroscopic investigations show an excellent purity. We report about the process and first investigations of the properties of the synthesized nickel nanomaterial

Efficient synthesis of benzothiazine and acrylamide compounds

Energy Technology Data Exchange (ETDEWEB)

Souza, Ana Maria Alves; Walfrido, Simone Torres Padua; Leite, Lucia Fernanda Costa; Lima, Maria Carmo Alves; Galdino, Suely Lins; Pitta, Ivan Rocha [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil). Dept. de Antibioticos; Barbosa Filho, Jose Maria [Universidade Federal da Paraiba (UFPB), Joao Pessoa, PB (Brazil); Simone, Carlos Alberto de; Ellena, Javier Alcides, E-mail: irpitta@gmail.co [Universidade de Sao Paulo (USP), Sao Carlos, SP (Brazil). Inst. de Fisica

2010-07-01

This article describes the synthesis of the new (2Z)-2-(4-methoxybenzylidene)-6-nitro-4H -benzo[1,4]thiazine-3-one, (2Z)-2-(4-methoxybenzylidene)-4-methyl-6-nitro-4H-benzo[1,4]thiazine-3-one, (2Z)-6-amino-2-(4-methoxybenzylidene)-4H -benzo[1,4]thiazine-3-one, (2Z)-6-butylamino-2-(4-methoxybenzylidene)-4-methyl-4H-benzo[1,4] -thiazine-3-one and (2E)-N-alkyl-N-(2-hydroxy-5-nitrophenyl) -3-phenylacrylamides and the spectroscopic data. The arylidenebenzothiazine compounds were prepared using the Knoevenagel condensation with substituted benzaldehydes in the presence of sodium methoxide in DMF. The presence of a nitro substituent in the 4-position, water and a slightly acid reaction medium in this condensation caused the rupture of the benzothiazine ring and subsequent formation of the phenylacrylamide compounds. A crystallographic data was presented for (2E)-3-(4-bromophenyl)-N-dodecyl-N -(2-hydroxy-5-nitrophenyl) acrylamide. (author)

Efficient synthesis of benzothiazine and acrylamide compounds

International Nuclear Information System (INIS)

Souza, Ana Maria Alves; Walfrido, Simone Torres Padua; Leite, Lucia Fernanda Costa; Lima, Maria Carmo Alves; Galdino, Suely Lins; Pitta, Ivan Rocha; Simone, Carlos Alberto de; Ellena, Javier Alcides

2010-01-01

This article describes the synthesis of the new (2Z)-2-(4-methoxybenzylidene)-6-nitro-4H -benzo[1,4]thiazine-3-one, (2Z)-2-(4-methoxybenzylidene)-4-methyl-6-nitro-4H-benzo[1,4]thiazine-3-one, (2Z)-6-amino-2-(4-methoxybenzylidene)-4H -benzo[1,4]thiazine-3-one, (2Z)-6-butylamino-2-(4-methoxybenzylidene)-4-methyl-4H-benzo[1,4] -thiazine-3-one and (2E)-N-alkyl-N-(2-hydroxy-5-nitrophenyl) -3-phenylacrylamides and the spectroscopic data. The arylidenebenzothiazine compounds were prepared using the Knoevenagel condensation with substituted benzaldehydes in the presence of sodium methoxide in DMF. The presence of a nitro substituent in the 4-position, water and a slightly acid reaction medium in this condensation caused the rupture of the benzothiazine ring and subsequent formation of the phenylacrylamide compounds. A crystallographic data was presented for (2E)-3-(4-bromophenyl)-N-dodecyl-N -(2-hydroxy-5-nitrophenyl) acrylamide. (author)

Polarized spectroscopic properties of Nd3+-doped KGd(WO4)2 single crystal

International Nuclear Information System (INIS)

Chen Yujin; Lin Yanfu; Gong Xinghong; Tan Qiguang; Zhuang Jian; Luo Zundu; Huang Yidong

2007-01-01

The polarized absorption spectra, infrared fluorescence spectra, upconversion visible fluorescence spectra, and fluorescence decay curve of orientated Nd 3+ :KGd(WO 4 ) 2 crystal were measured at room-temperature. Some important spectroscopic parameters were investigated in detail in the framework of the Judd-Ofelt theory and the Fuchtbauer-Ladenburg formula. The effect of the crystal structure on the spectroscopic properties of the Nd 3+ ions was analyzed. The relation among the spectroscopic parameters and the laser performances of the Nd 3+ :KGd(WO 4 ) 2 crystal was discussed

Synthesis, molecular structure, spectroscopic properties and stability of (Z)-N-methyl-C-2,4,6-trimethylphenylnitrone

Science.gov (United States)

Lasri, Jamal; Ismail, Ali I.; Haukka, Matti; Soliman, Saied M.

2015-02-01

New N-methyl-C-2,4,6-trimethylphenylnitrone 1 has been synthesized starting from N-methylhydroxylamine and mesitaldehyde. The product was fully characterized using different spectroscopic techniques; FTIR, NMR, UV-Vis, high resolution mass spectrometry and X-ray diffraction. The relative stability and percent of population of its two possible isomers (E and Z) were calculated using the B3LYP/6-311++G(d,p) method in gas phase and in solution. In agreement with the X-ray results, it was found that Z-isomer is the most stable one in both gas phase and solution. The molecular geometry, vibrational frequencies, gauge-including atomic orbital (GIAO), and chemical shift values were also calculated using the same level of theory. The TD-DFT results of the studied nitrone predicted a π-π∗ transition band at 285.1 nm (fosc = 0.3543) in the gas phase. The rest of the spectral bands undergo either hyperchromic or hypsochromic shifts in the presence of solvent. Polarizability and HOMO-LUMO gap values were used to predict the nonlinear optical properties (NLO) of the studied compound. NBO analysis has been used to determine the most accurate Lewis structure of the studied molecule.

The VANDELS ESO public spectroscopic survey

Science.gov (United States)

McLure, R. J.; Pentericci, L.; Cimatti, A.; Dunlop, J. S.; Elbaz, D.; Fontana, A.; Nandra, K.; Amorin, R.; Bolzonella, M.; Bongiorno, A.; Carnall, A. C.; Castellano, M.; Cirasuolo, M.; Cucciati, O.; Cullen, F.; De Barros, S.; Finkelstein, S. L.; Fontanot, F.; Franzetti, P.; Fumana, M.; Gargiulo, A.; Garilli, B.; Guaita, L.; Hartley, W. G.; Iovino, A.; Jarvis, M. J.; Juneau, S.; Karman, W.; Maccagni, D.; Marchi, F.; Mármol-Queraltó, E.; Pompei, E.; Pozzetti, L.; Scodeggio, M.; Sommariva, V.; Talia, M.; Almaini, O.; Balestra, I.; Bardelli, S.; Bell, E. F.; Bourne, N.; Bowler, R. A. A.; Brusa, M.; Buitrago, F.; Caputi, K. I.; Cassata, P.; Charlot, S.; Citro, A.; Cresci, G.; Cristiani, S.; Curtis-Lake, E.; Dickinson, M.; Fazio, G. G.; Ferguson, H. C.; Fiore, F.; Franco, M.; Fynbo, J. P. U.; Galametz, A.; Georgakakis, A.; Giavalisco, M.; Grazian, A.; Hathi, N. P.; Jung, I.; Kim, S.; Koekemoer, A. M.; Khusanova, Y.; Fèvre, O. Le; Lotz, J. M.; Mannucci, F.; Maltby, D. T.; Matsuoka, K.; McLeod, D. J.; Mendez-Hernandez, H.; Mendez-Abreu, J.; Mignoli, M.; Moresco, M.; Mortlock, A.; Nonino, M.; Pannella, M.; Papovich, C.; Popesso, P.; Rosario, D. P.; Salvato, M.; Santini, P.; Schaerer, D.; Schreiber, C.; Stark, D. P.; Tasca, L. A. M.; Thomas, R.; Treu, T.; Vanzella, E.; Wild, V.; Williams, C. C.; Zamorani, G.; Zucca, E.

2018-05-01

VANDELS is a uniquely-deep spectroscopic survey of high-redshift galaxies with the VIMOS spectrograph on ESO's Very Large Telescope (VLT). The survey has obtained ultra-deep optical (0.48 studies. Using integration times calculated to produce an approximately constant signal-to-noise ratio (20 motivation, survey design and target selection.

Synthesis and spectroscopic characterization of magnetic hydroxyapatite nanocomposite using ultrasonic irradiation

Science.gov (United States)

Gopi, D.; Ansari, M. Thameem; Shinyjoy, E.; Kavitha, L.

2012-02-01

Nowadays magnetic hydroxyapatite (m-HAP) has potential applications in biomedicine more especially for bone cancer treatment. In this paper the functionalization of the hydroxyapatite (HAP) with magnetite nanoparticle (MNP) through ultrasonic irradiation technique is reported and its spectral investigation has been carried out. The ultrasonic irradiation with two different frequencies of 28 kHz and 35 kHz at the power of 150 and 320 W, respectively, was employed for the synthesis of m-HAP. The ultrasound irradiation of 35 kHz at 320 W shows the efficient diffusion of MNP to the HAP host matrix leads to the formation of m-HAP. The ultrasonic irradiation technique does not require stabilizers as in the case of coprecipitation method hence the final product of pure m-HAP is obtained. The X-ray diffraction pattern shows the formation of magnetite nanoparticles which are functionalized with hydroxyapatite host matrix. The vibrating sample magnetometer curve exhibits the super paramagnetic property of the samples and the saturation magnetization ( Ms) value of the functionalized magnetic hydroxyapatite. The Ms value is found to be much less than that of pure magnetite nanoparticle and this decrement in Ms is due to the hindrance of magnetic domain of the particles with HAP. The portrayed Raman spectra discriminate between the m-HAP and MNP with corresponding vibrational modes of frequencies. The transmission electron micrograph shows excellent morphology of functionalized m-HAP in nanometer range. The atomic force microscopic investigation shows the 3-dimensional view of crust and trench shape of m-HAP. All these results confirm the formation of magnetic hydroxyapatite nanocomposite with typical magnetic property for biological applications.

How spectroscopic x-ray imaging benefits from inter-pixel communication

CERN Document Server

Koenig, Thomas; Hamann, Elias; Cecilia, Angelica; Ballabriga, Rafael; Campbell, Michael; Ruat, Marie; Tlustos, Lukas; Fauler, Alex; Fiederle, Michael; Baumbach, Tilo

2014-01-01

Spectroscopic x-ray imaging based on pixellated semiconductor detectors can be sensitive to charge sharing and K-fluorescence, depending on the sensor material used, its thickness and the pixel pitch employed. As a consequence, spectroscopic resolution is partially lost. In this paper, we study a new detector ASIC, the Medipix3RX, that offers a novel feature called charge summing, which is established by making adjacent pixels communicate with each other. Consequently, single photon interactions resulting in multiple hits are almost completely avoided. We investigate this charge summing mode with respect to those of its imaging properties that are of interest in medical physics and benchmark them against the case without charge summing. In particular, we review its influence on spectroscopic resolution and find that the low energy bias normally present when recording energy spectra is dramatically reduced. Furthermore, we show that charge summing provides a modulation transfer function which is almost indepen...

Synthesis of nanostructured polyaniline

Science.gov (United States)

Surwade, Sumedh P.

The organization of my thesis is as follows: (a) Chapter III describes the synthesis of bulk quantities of polyaniline nanofibers in one step using a simple and versatile high ionic strength aqueous system (HCl/NaCl) that permits the use of pure H2O2 as a mild oxidant without any added metal or enzyme catalyst. Polyaniline nanofibers obtained are highly conducting, sigma˜1--5 S/cm, and spectroscopically similar to conventional polyaniline synthesized using stronger oxidants. The synthesis method is further extended to the synthesis of oligoanilines of controlled molecular weight, e.g., aniline tetramer, octamer, and hexadecamer. Microns long tetramer nanofibers are synthesized using this method. (b) Chapter IV describes the mechanism of nanofiber formation in polyaniline. It is proposed that the surfaces such as the walls of the reaction vessel and/or intentionally added surfaces play a dramatic role in the evolution of nanofibrillar morphology. Nucleation sites on surfaces promote the accumulation of aniline dimer that reacts further to yield aniline tetramer, which (surprisingly) is entirely in form of nanofibers and whose morphology is transcribed to the bulk by a double heterogeneous nucleation mechanism. This unexpected phenomenon could form the basis of nanofiber formation in all classes of precipitation polymerization systems. (c) Chapter V is the mechanistic study on the formation of oligoanilines during the chemical oxidation of aniline in weakly acidic, neutral or basic media using peroxydisulfate oxidant. It is proposed that the reaction proceeds via the intermediacy of benzoquinone monoimine that is formed as a result of a Boyland-Sims rearrangement of aniline. The initial role of peroxydisulfate is to provide a pathway for the formation of benzoquinone monoimine intermediate that is followed by a conjugate Michael-type addition reaction with aniline or sulfated anilines. The products isolated in pH 2.5--10.0 buffers are intermediate species at various

Understanding arsenic metabolism through spectroscopic determination of arsenic in human urine

OpenAIRE

Brima, Eid I.; Jenkins, Richard O.; Haris, Parvez I.

2006-01-01

In this review we discuss a range of spectroscopic techniques that are currently used for analysis of arsenic in human urine for understanding arsenic metabolism and toxicity, especially in relation to genetics/ethnicity, ingestion studies and exposure to arsenic through drinking water and diet. Spectroscopic techniques used for analysis of arsenic in human urine include inductively coupled plasma mass spectrometry (ICP-MS), hydride generation atomic absorption spectrometry (HG-AAS), hydride ...

Synthesis and molecular characterization of chitosan based polyurethane elastomers using aromatic diisocyanate.

Science.gov (United States)

Zia, Khalid Mahmood; Anjum, Sohail; Zuber, Mohammad; Mujahid, Muhammad; Jamil, Tahir

2014-05-01

The present research work was performed to synthesize a new series of chitosan based polyurethane elastomers (PUEs) using poly(ɛ-caprolactone) (PCL). The chitosan based PUEs were prepared by step-growth polymerization technique using poly(ɛ-caprolactone) (PCL) and 2,4-toluene diisocyanate (TDI). In the second step the PU prepolymer was extended with different mole ratios of chitosan and 1,4-butane diol (BDO). Molecular engineering was carried out during the synthesis. The conventional spectroscopic characterization of the synthesized samples using FT-IR confirms the existence of the proposed chitosan based PUEs structure. Internal morphology of the prepared PUEs was studied using SEM analysis. The SEM images confirmed the incorporation of chitosan molecules into the PU backbone. Copyright © 2014 Elsevier B.V. All rights reserved.

Single nanoparticle tracking spectroscopic microscope

Science.gov (United States)

Yang, Haw [Moraga, CA; Cang, Hu [Berkeley, CA; Xu, Cangshan [Berkeley, CA; Wong, Chung M [San Gabriel, CA

2011-07-19

A system that can maintain and track the position of a single nanoparticle in three dimensions for a prolonged period has been disclosed. The system allows for continuously imaging the particle to observe any interactions it may have. The system also enables the acquisition of real-time sequential spectroscopic information from the particle. The apparatus holds great promise in performing single molecule spectroscopy and imaging on a non-stationary target.

HITRAN Application Programming Interface (HAPI): A comprehensive approach to working with spectroscopic data

International Nuclear Information System (INIS)

Kochanov, R.V.; Gordon, I.E.; Rothman, L.S.; Wcisło, P.; Hill, C.; Wilzewski, J.S.

2016-01-01

The HITRAN Application Programming Interface (HAPI) is presented. HAPI is a free Python library, which extends the capabilities of the HITRANonline interface ( (www.hitran.org)) and can be used to filter and process the structured spectroscopic data. HAPI incorporates a set of tools for spectra simulation accounting for the temperature, pressure, optical path length, and instrument properties. HAPI is aimed to facilitate the spectroscopic data analysis and the spectra simulation based on the line-by-line data, such as from the HITRAN database [JQSRT (2013) 130, 4–50], allowing the usage of the non-Voigt line profile parameters, custom temperature and pressure dependences, and partition sums. The HAPI functions allow the user to control the spectra simulation and data filtering process via a set of the function parameters. HAPI can be obtained at its homepage (www.hitran.org/hapi). - Highlights: • HAPI extends the HITRANonline portal and provides an access to the HITRAN data. • Free, flexible, and portable Python library for working with the spectroscopic data. • Incorporates functions for querying, filtering and processing the spectroscopic data. • Provides functionality for single-layer spectra simulation. • Can be used in the radiative transfer codes, spectroscopic data validation, etc.

Are your Spectroscopic Data Being Used?

Science.gov (United States)

Gordon, Iouli E.; Rothman, Laurence S.; Wilzewski, Jonas

2014-06-01

Spectroscopy is an established and indispensable tool in science, industry, agriculture, medicine, surveillance, etc.. The potential user of spectral data, which is not available in HITRAN or other databases, searches the spectroscopy publications. After finding the desired publication, the user very often encounters the following problems: 1) They cannot find the data described in the paper. There can be many reasons for this: nothing is provided in the paper itself or supplementary material; the authors are not responding to any requests; the web links provided in the paper have long been broken; etc. 2) The data is presented in a reduced form, for instance through the fitted spectroscopic constants. While this is a long-standing practice among spectroscopists, there are numerous serious problems with this practice, such as users getting different energy and intensity values because of different representations of the solution to the Hamiltonian, or even just despairing of trying to generate usable line lists from the published constants. Properly providing the data benefits not only users but also the authors of the spectroscopic research. We will show that this increases citations to the spectroscopy papers and visibility of the research groups. We will also address the quite common issue when researchers obtain the data, but do not feel that they have time, interest or resources to write an article describing it. There are modern tools that would allow one to make these data available to potential users and still get credit for it. However, this is a worst case scenario recommendation, i.e., publishing the data in a peer-reviewed journal is still the preferred way. L. S. Rothman, I. E. Gordon, et al. "The HITRAN 2012 molecular spectroscopic database," JQSRT 113, 4-50 (2013).

New Insight into the Observation of Spectroscopic Strength Reduction in Atomic Nuclei: Implication for the Physical Meaning of Spectroscopic Factors

International Nuclear Information System (INIS)

Timofeyuk, N. K.

2009-01-01

Experimental studies of one-nucleon knockout from magic nuclei suggest that their nucleon orbits are not fully occupied. This conflicts a commonly accepted view of the shell closure associated with such nuclei. The conflict can be reconciled if the overlap between initial and final nuclear states in a knockout reaction are calculated by a nonstandard method. The method employs an inhomogeneous equation based on correlation-dependent effective nucleon-nucleon interactions and allows the simplest wave functions, in which all nucleons occupy only the lowest nuclear orbits, to be used. The method also reproduces the recently established relation between reduction of spectroscopic strength, observed in knockout reactions on other nuclei, and nucleon binding energies. The implication of the inhomogeneous equation method for the physical meaning of spectroscopic factors is discussed.

Automated reliability assessment for spectroscopic redshift measurements

Science.gov (United States)

Jamal, S.; Le Brun, V.; Le Fèvre, O.; Vibert, D.; Schmitt, A.; Surace, C.; Copin, Y.; Garilli, B.; Moresco, M.; Pozzetti, L.

2018-03-01

Context. Future large-scale surveys, such as the ESA Euclid mission, will produce a large set of galaxy redshifts (≥106) that will require fully automated data-processing pipelines to analyze the data, extract crucial information and ensure that all requirements are met. A fundamental element in these pipelines is to associate to each galaxy redshift measurement a quality, or reliability, estimate. Aim. In this work, we introduce a new approach to automate the spectroscopic redshift reliability assessment based on machine learning (ML) and characteristics of the redshift probability density function. Methods: We propose to rephrase the spectroscopic redshift estimation into a Bayesian framework, in order to incorporate all sources of information and uncertainties related to the redshift estimation process and produce a redshift posterior probability density function (PDF). To automate the assessment of a reliability flag, we exploit key features in the redshift posterior PDF and machine learning algorithms. Results: As a working example, public data from the VIMOS VLT Deep Survey is exploited to present and test this new methodology. We first tried to reproduce the existing reliability flags using supervised classification in order to describe different types of redshift PDFs, but due to the subjective definition of these flags (classification accuracy 58%), we soon opted for a new homogeneous partitioning of the data into distinct clusters via unsupervised classification. After assessing the accuracy of the new clusters via resubstitution and test predictions (classification accuracy 98%), we projected unlabeled data from preliminary mock simulations for the Euclid space mission into this mapping to predict their redshift reliability labels. Conclusions: Through the development of a methodology in which a system can build its own experience to assess the quality of a parameter, we are able to set a preliminary basis of an automated reliability assessment for

Infrared spectroscopic ellipsometry of micrometer-sized SiO2 line gratings

Science.gov (United States)

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.

Spectroscopic Doppler analysis for visible-light optical coherence tomography

Science.gov (United States)

Shu, Xiao; Liu, Wenzhong; Duan, Lian; Zhang, Hao F.

2017-12-01

Retinal oxygen metabolic rate can be effectively measured by visible-light optical coherence tomography (vis-OCT), which simultaneously quantifies oxygen saturation and blood flow rate in retinal vessels through spectroscopic analysis and Doppler measurement, respectively. Doppler OCT relates phase variation between sequential A-lines to the axial flow velocity of the scattering medium. The detectable phase shift is between -π and π due to its periodicity, which limits the maximum measurable unambiguous velocity without phase unwrapping. Using shorter wavelengths, vis-OCT is more vulnerable to phase ambiguity since flow induced phase variation is linearly related to the center wavenumber of the probing light. We eliminated the need for phase unwrapping using spectroscopic Doppler analysis. We split the whole vis-OCT spectrum into a series of narrow subbands and reconstructed vis-OCT images to extract corresponding Doppler phase shifts in all the subbands. Then, we quantified flow velocity by analyzing subband-dependent phase shift using linear regression. In the phantom experiment, we showed that spectroscopic Doppler analysis extended the measurable absolute phase shift range without conducting phase unwrapping. We also tested this method to quantify retinal blood flow in rodents in vivo.

Spectroscopic follow up of Kepler planet candidates

DEFF Research Database (Denmark)

Latham..[], D. W.; Cochran, W. D.; Marcy, G.W.

2010-01-01

Spectroscopic follow-up observations play a crucial role in the confirmation and characterization of transiting planet candidates identified by Kepler. The most challenging part of this work is the determination of radial velocities with a precision approaching 1 m/s in order to derive masses from...... spectroscopic orbits. The most precious resource for this work is HIRES on Keck I, to be joined by HARPS-North on the William Herschel Telescope when that new spectrometer comes on line in two years. Because a large fraction of the planet candidates are in fact stellar systems involving eclipsing stars...... and not planets, our strategy is to start with reconnaissance spectroscopy using smaller telescopes, to sort out and reject as many of the false positives as possible before going to Keck. During the first Kepler observing season in 2009, more than 100 nights of telescope time were allocated for this work, using...

Spectroscopic Characterization of Key Aromatic Molecules: A Route toward The Origin of Life.

Science.gov (United States)

Puzzarini, Cristina; Baiardi, Alberto; Bloino, Julien; Barone, Vincenzo; Murphy, Thomas E; Drew, Dennis; Ali, Ashraf

2017-08-04

To gain information on the abiotic synthesis of the building blocks of life from simple molecules, and their subsequent chemical evolution to biological systems, the starting point is the identification of target species in Titan-like planets, i.e., planets that resemble the primitive Earth, as well as in Earth-like planets in the habitable zone of their star, namely planets where life can be already originated. In this scenario, molecular spectroscopy plays a crucial role because spectroscopic signatures are at the basis of an unequivocal proof for the presence of these target molecules. Thanks to the advances in many different techniques and to the NASA successful Kepler exoplanet transit mission, thousands of diverse planets outside of our solar system have been discovered. The James Webb Space Telescope (JWST), scheduled to be launched in 2018, will be very helpful in the identification of biosignature gases in Earth-like planets' atmospheres and of prebiotic molecule signatures in Titan-like atmospheres by observing their absorption during transits. While the search for key-target molecules in exoplanet atmospheres can be carried out by the JWST Transit Spectroscopy in the infrared (IR) region (0.6 - 29 µm wavelength range), opportunities for their detection in protostellar cores, protoplanetary disks and on Titan are also offered by the interferometric high spectral and spatial resolution observations using the Atacama Large Millimeter/submillimeter Array (ALMA). In the present work, target molecules have been selected and their spectroscopic characterization presented in view of supporting their infrared and complementary millimeter/submillimeter-wave spectral observations. In detail, the selected target molecules include: (1) the three-membered oxygen-containing heterocycles: oxirane and protonated oxirane, (2) the cyclopropenyl cation and its methyl derivative, (3) two examples of ortho- and peri-fused tri-cyclic aromatic rings, i.e., the phenalenyl

Synthesis of Cu[MIBI]4Cl to prepare 99m Tc [MIBI]6+ as a myocardial perfusion agent

International Nuclear Information System (INIS)

Ramirez G, L.

1994-01-01

2-Methoxyisobutylisonitrile (MIBI) is a key starting material in the preparation of technetium-99m hexakis (2-methoxyisobutylisonitrile). This cationic complex has been reported to be clinically useful as myocardial perfusion agent. In this work, we designed an improved synthetic method to prepare 2-methoxyisobutylisonitrile in a two step synthesis with an overall yield of 52.9 % , on the basis of 2-methoxyisobutylamine is a primary amine which, when is heated with a mixture of chloroform and alcoholic potash, produces an isonitrile. Its spectroscopic properties as well as the preparation of its copper and technetium-99m complexes are also presented. (Author)

Spectroscopic methods for detection of impurities in water

Science.gov (United States)

Strashnikova, Natalia V.; Papiashvili, Nona; Cohen-Luria, Rivka; Mark, Shlomo; Shilon, Guy; Khankin, Daniel; Kalisky, Yehoshua; Kalisky, Ofra; Parola, Abraham H.

2011-11-01

Optical photoluminescence spectroscopic method for detection of impurities, hazardous materials, pesticides, and pollutants in water resources, both qualitatively and quantitatively, is presented. The method is based on synchronous fluorescence spectroscopy (SFS) of organic aromatic compounds, or poly-aromatic hydrocarbons (PAH), and is carried out by following simultaneously their excitation and emission spectra. The full excitation emission matrix (EEM) generated in this way provides a 2-D and 3-D fluorescence map of the tested sample and the diagonals through the axes origin provide the synchronous fluorescence spectra at a constant wavelengths differences between the emission and excitation wavelengths, thus enabling multitude components identification. This map contains all the relevant spectroscopic information of the tested sample, and serves as a unique "fingerprint" with a very specific and accurate identification. When compared with pre-determined spectra and calibration curves from a "databank", there is a one-toone correspondence between the image and the specific compound, and it can be identified accurately both qualitatively and quantitatively. This method offers several significant advantages, and it provides a sensitive (ppm detection level), accurate and simple spectroscopic tool to monitor impurities and pollutants in water. The design and performance of the spectrofluorimeter prototype, as well as the software development and analysis of chemical organic compounds and mixtures in water will be discussed in this paper.

Spectroscopic characterization of manganese-doped alkaline earth

Indian Academy of Sciences (India)

The intensity and frequency variations for the characteristic phosphate group vibrations have been correlated with the changes of the structural units present in these glasses. Depolymerization of the phosphate chains in all the glasses is observed with replacement of alkaline earth content by spectroscopic studies.

Synthesis, Spectroscopic Characterization, and Biological Activities of Metal Complexes of 4-((4-Chlorophenyldiazenyl-2-((p-tolyliminomethylphenol

Directory of Open Access Journals (Sweden)

C. Anitha

2013-01-01

Full Text Available Azo Schiff base complexes of VO(II, Mn(II, Co(II, Ni(II, Cu(II, and Zn(II have been synthesized from 4-((4-chlorophenyldiazenyl-2-((p-tolyliminomethylphenol (CDTMP. The nature of bonding and the structural features of the complexes have been deduced from elemental analysis, molar conductance, magnetic susceptibility measurements, IR, UV-Vis, 1H-NMR, EPR, mass, SEM, and fluorescence spectral studies. Spectroscopic and other analytical studies reveal square-planar geometry for copper, square-pyramidal geometry for oxovanadium, and octahedral geometry for other complexes. The EPR spectra of copper(II complex in DMSO at 300 K and 77 K were recorded, and its salient features are reported. Antimicrobial studies against several microorganisms indicate that the complexes are more potent bactericides and fungicides than the ligand. The electrochemical behavior of the copper(II complex was studied by cyclic voltammetry. All the synthesized compounds can serve as potential photoactive materials as indicated from their characteristic fluorescence properties. The second harmonic conversion efficiency of the synthesized azo Schiff base was found to be higher than that of urea and KDP (potassium dihydrogen phosphate. SEM image of copper(II complex implies the crystalline state and surface morphology of the complex.

Synthesis, spectroscopic, structural and thermal characterizations of vanadyl(IV) adenine complex prospective as antidiabetic drug agent

Science.gov (United States)

El-Megharbel, Samy M.; Hamza, Reham Z.; Refat, Moamen S.

2015-01-01

The vanadyl(IV) adenine complex; [VO(Adn)2]ṡSO4; was synthesized and characterized. The molar conductivity of this complex was measured in DMSO solution that showed an electrolyte nature. Spectroscopic investigation of the green solid complex studied here indicate that the adenine acts as a bidentate ligand, coordinated to vanadyl(IV) ions through the nitrogen atoms N7 and nitrogen atom of amino group. Thus, from the results presented the vanadyl(IV) complex has square pyramid geometry. Further characterizations using thermal analyses and scanning electron techniques was useful. The aim of this paper was to introduce a new drug model for the diabetic complications by synthesized a novel mononuclear vanadyl(IV) adenine complex to mimic insulin action and reducing blood sugar level. The antidiabetic ability of this complex was investigated in STZ-induced diabetic mice. The results suggested that VO(IV)/adenine complex has antidiabetic activity, it improved the lipid profile, it improved liver and kidney functions, also it ameliorated insulin hormone and blood glucose levels. The vanadyl(IV) complex possesses an antioxidant activity and this was clear through studying SOD, CAT, MDA, GSH and methionine synthase. The current results support the therapeutic potentiality of vanadyl(IV)/adenine complex for the management and treatment of diabetes.

Synthesis and spectroscopic characterization of gold nanoparticles via plasma-liquid interaction technique

Science.gov (United States)

Khatoon, N.; Yasin, H. M.; Younus, M.; Ahmed, W.; Rehman, N. U.; Zakaullah, M.; Iqbal, M. Zafar

2018-01-01

Fabrication of non-functionalized gold nanoparticles is interesting owing to their potential applications in sensing and biomedicine. We report on the synthesis of surfactant-free gold nanoparticles (AuNPs) by Plasma-Liquid Interaction (PLI) technique, using micro-atmospheric pressure D.C. plasma. The effects of discharge parameters, such as discharge current, precursor concentration and gas flow rates on the structure and morphology of AuNPs have been investigated. Optical Emission Spectroscopy (OES) was employed to estimate the UV radiation intensity and OH radical density. Scanning electron microscopy (SEM) and ultraviolet-visible (UV-Vis) optical spectroscopy were employed to study the morphology and structure of AuNPs. The normalized intensities of UV radiation and OH radical density found to increase with increase in discharge current. We observed that the particle size can be tuned by controlling any of the following parameters: intensity of the UV radiation, OH radical density, and concentration of the Au precursor. Interestingly, we found that addition of 1% Ar in the feedstock gas results in formation of relatively uniform size distribution of nanoparticles. The surfactant-free AuNPs, due to their bare-surface, exhibit excellent surface-enhanced Raman scattering (SERS) properties. The SERS study of Rhodamine 6G using AuNPs as substrates, shows significant Raman enhancement and fluorescence quenching, which makes our technique a potentially powerful route to detection of trace amounts of dangerous explosives and other materials.

Multi-spectroscopic techniques to evaluate the toxicity of alloyed CdSeS quantum dots

International Nuclear Information System (INIS)

Zhan Hongju; Zhou Peijiang; Ding Ling; He Zhenyu; Ma Rong

2012-01-01

Alloyed CdSeS quantum dots (QDs) were successfully synthesized in aqueous phase using microwave irradiation. UV–vis spectroscopy, fluorescence spectroscopy, transmission electron microscopy (TEM) and X-ray diffraction (XRD) techniques proved that the prepared alloyed QDs are composed of a CdSe-rich core and thick CdS shell with homogeneous size distributions. In order to study its biological toxicity, multi-spectroscopic techniques were adopted to investigate their conjugation with BSA. Fluorescence quenching methods indicated the prepared CdSeS QDs strongly quenched the fluorescence of BSA due to the formation of non-fluorescence ground-state complex. UV–vis absorbance spectra, synchronous fluorescence spectra and CD spectra further confirmed the alloyed CdSeS QDs binded with BSA and destroyed their hydrogen bonding networks, which induced the conformation changes of this macromolecule. - Highlights: ► Synthesis of alloyed CdSeS QDs in aqueous phase via microwave irradiation. ► Characterization of alloyed QDs by PL, UV–vis, XRD and TEM techniques. ► Evidence of static quenching between alloyed QDs and BSA. ► Evidence of the conformation change of BSA molecules induced by alloyed QDs.

Spectroscopic, thermal and biological studies of coordination

Indian Academy of Sciences (India)

Spectroscopic, thermal and biological studies of coordination compounds of sulfasalazine drug: Mn(II), Hg(II), Cr(III), ZrO(II), VO(II) and Y(III) transition metal ... The thermal decomposition of the complexes as well as thermodynamic parameters ( *}, *, * and *) were estimated using Coats–Redfern and ...

THE YOUNG SOLAR ANALOGS PROJECT. I. SPECTROSCOPIC AND PHOTOMETRIC METHODS AND MULTI-YEAR TIMESCALE SPECTROSCOPIC RESULTS

Energy Technology Data Exchange (ETDEWEB)

Gray, R. O.; Briley, M. M.; Lambert, R. A.; Fuller, V. A.; Newsome, I. M.; Seeds, M. F. [Department of Physics and Astronomy, Appalachian State University, Boone, NC 26808 (United States); Saken, J. M.; Kahvaz, Y. [Department of Physics and Physical Science, Marshall University, Huntington, WV 25755 (United States); Corbally, C. J. [Vatican Observatory Research Group, Steward Observatory, Tucson, AZ 85721-0065 (United States)

2015-12-15

This is the first in a series of papers presenting methods and results from the Young Solar Analogs Project, which began in 2007. This project monitors both spectroscopically and photometrically a set of 31 young (300–1500 Myr) solar-type stars with the goal of gaining insight into the space environment of the Earth during the period when life first appeared. From our spectroscopic observations we derive the Mount Wilson S chromospheric activity index (S{sub MW}), and describe the method we use to transform our instrumental indices to S{sub MW} without the need for a color term. We introduce three photospheric indices based on strong absorption features in the blue-violet spectrum—the G-band, the Ca i resonance line, and the Hydrogen-γ line—with the expectation that these indices might prove to be useful in detecting variations in the surface temperatures of active solar-type stars. We also describe our photometric program, and in particular our “Superstar technique” for differential photometry which, instead of relying on a handful of comparison stars, uses the photon flux in the entire star field in the CCD image to derive the program star magnitude. This enables photometric errors on the order of 0.005–0.007 magnitude. We present time series plots of our spectroscopic data for all four indices, and carry out extensive statistical tests on those time series demonstrating the reality of variations on timescales of years in all four indices. We also statistically test for and discover correlations and anti-correlations between the four indices. We discuss the physical basis of those correlations. As it turns out, the “photospheric” indices appear to be most strongly affected by emission in the Paschen continuum. We thus anticipate that these indices may prove to be useful proxies for monitoring emission in the ultraviolet Balmer continuum. Future papers in this series will discuss variability of the program stars on medium (days–months) and short

EEL spectroscopic tomography: towards a new dimension in nanomaterials analysis.

Science.gov (United States)

Yedra, Lluís; Eljarrat, Alberto; Arenal, Raúl; Pellicer, Eva; Cabo, Moisés; López-Ortega, Alberto; Estrader, Marta; Sort, Jordi; Baró, Maria Dolors; Estradé, Sònia; Peiró, Francesca

2012-11-01

Electron tomography is a widely spread technique for recovering the three dimensional (3D) shape of nanostructured materials. Using a spectroscopic signal to achieve a reconstruction adds a fourth chemical dimension to the 3D structure. Up to date, energy filtering of the images in the transmission electron microscope (EFTEM) is the usual spectroscopic method even if most of the information in the spectrum is lost. Unlike EFTEM tomography, the use of electron energy-loss spectroscopy (EELS) spectrum images (SI) for tomographic reconstruction retains all chemical information, and the possibilities of this new approach still remain to be fully exploited. In this article we prove the feasibility of EEL spectroscopic tomography at low voltages (80 kV) and short acquisition times from data acquired using an aberration corrected instrument and data treatment by Multivariate Analysis (MVA), applied to Fe(x)Co((3-x))O(4)@Co(3)O(4) mesoporous materials. This approach provides a new scope into materials; the recovery of full EELS signal in 3D. Copyright © 2012 Elsevier B.V. All rights reserved.

Model Catalysis of Ammonia Synthesis ad Iron-Water Interfaces - ASum Frequency Generation Vibrational Spectroscopic Study of Solid-GasInterfaces and Anion Photoelectron Spectroscopic Study of Selected Anionclusters

Energy Technology Data Exchange (ETDEWEB)

Ferguson, Michael James [Univ. of California, Berkeley, CA (United States)

2005-01-01

The ammonia synthesis reaction has been studied using single crystal model catalysis combined with sum frequency generation (SFG) vibrational spectroscopy. The adsorption of gases N₂, H₂, O₂ and NH₃ that play a role in ammonia synthesis have been studied on the Fe(111) crystal surface by sum frequency generation vibrational spectroscopy using an integrated Ultra-High Vacuum (UHV)/high-pressure system. SFG spectra are presented for the dissociation intermediates, NH₂ (~3325 cm^-1) and NH (~3235 cm^-1) under high pressure of ammonia or equilibrium concentrations of reactants and products on Fe(111) surfaces. Special attention was paid to understand how potassium promotion of the iron catalyst affects the intermediates of ammonia synthesis. An Fe(111) surface promoted with 0.2 monolayers of potassium red shifts the vibrational frequencies of the reactive surface intermediates, NH and NH₂, providing evidence for weakened the nitrogen-hydrogen bonds relative to clean Fe(111). Spectral features of these surface intermediates persisted to higher temperatures for promoted iron surfaces than for clean Fe(111) surfaces implying that nitrogen-iron bonds are stronger for the promoted surface. The ratio of the NH to NH₂ signal changed for promoted surfaces in the presence of equilibrium concentrations of reactants and products. The order of adding oxygen and potassium to promoted surfaces does not alter the spectra indicating that ammonia induces surface reconstruction of the catalyst to produce the same surface morphology. When oxygen is co-adsorbed with nitrogen, hydrogen, ammonia or potassium on Fe(111), a relative phase shift of the spectra occurs as compared to the presence of adsorbates on clean iron surfaces. Water adsorption on iron was also probed using SFG vibrational spectroscopy. For both H₂O and D₂O, the only spectral feature was in the range of

8th Czechoslovak spectroscopic conference. Abstracts

International Nuclear Information System (INIS)

1988-01-01

Volume 3 of the conference proceedings contains abstracts of 17 invited papers, 101 poster presentations and 7 papers of instrument manufacturers, devoted to special spectroscopic techniques including X-ray microanalysis, X-ray spectral analysis, Moessbauer spectrometry, mass spectrometry, instrumental activation analysis and other instrumental radioanalytical methods, electron spectrometry, and techniques of environmental analysis. Sixty abstracts were inputted in INIS. (A.K.)

Spectroscopic investigation of Indium Bromide for lighting purposes

NARCIS (Netherlands)

Mulders, H.C.J.; Kroesen, G.M.W.; Haverlag, M.; Haverlag, M.; Kroesen, G.M.W.; Tagushi, T.

2010-01-01

Laser Induced Fluorescence was used to study the radiative properties of InBr for lighting purposes. Results include the temperature dependence of the fluorescence decay time, spectroscopic constants and rotational temperature determination from a LIF spectrum.

Facile synthesis of silver nanoparticles and their application in dye degradation

Energy Technology Data Exchange (ETDEWEB)

Joseph, Siby, E-mail: sibyjoseph4@gmail.com [Department of Chemistry, St. George' s College, Aruvithura, Kottayam 686122, Kerala (India); Mathew, Beena, E-mail: beenamscs@gmail.com [School of Chemical Sciences, Mahatma Gandhi University, Kottayam 686560, Kerala (India)

2015-05-15

Graphical abstract: - Highlights: • This synthetic method uses the novel reducing agent hexamine. • The method is simple, fast and environment friendly. • This is a cost-effective method as all materials used are inexpensive and readily available. • The method provides highly stable spherical silver nanoparticles. • The nanoparticles show outstanding catalytic activity in the degradation of organic dyes. - Abstract: The present article reports a simple, facile and eco-friendly method based on microwave irradiation for the synthesis of silver nanoparticles in aqueous medium using starch as stabilizing agent and a new reducing agent namely hexamine. The silver nanoparticles were characterized by UV–vis, FTIR, XRD and HR-TEM analysis. UV–vis spectroscopic studies provided sufficient evidences for the formation of nanoparticles. The role of starch in the synthesis and stabilization of the nanoparticles was obtained from FTIR studies. The XRD and HR-TEM investigations clearly demonstrated the crystalline nature of the nanoparticles. From the TEM images, the silver nanoparticles were found to be spherical and of nearly uniform size with an average diameter of 18.2 ± 0.97 nm. The nanoparticles showed excellent catalytic activity in the degradation of methyl orange and rhodamine B by NaBH{sub 4}.

Facile synthesis of silver nanoparticles and their application in dye degradation

International Nuclear Information System (INIS)

Joseph, Siby; Mathew, Beena

2015-01-01

Graphical abstract: - Highlights: • This synthetic method uses the novel reducing agent hexamine. • The method is simple, fast and environment friendly. • This is a cost-effective method as all materials used are inexpensive and readily available. • The method provides highly stable spherical silver nanoparticles. • The nanoparticles show outstanding catalytic activity in the degradation of organic dyes. - Abstract: The present article reports a simple, facile and eco-friendly method based on microwave irradiation for the synthesis of silver nanoparticles in aqueous medium using starch as stabilizing agent and a new reducing agent namely hexamine. The silver nanoparticles were characterized by UV–vis, FTIR, XRD and HR-TEM analysis. UV–vis spectroscopic studies provided sufficient evidences for the formation of nanoparticles. The role of starch in the synthesis and stabilization of the nanoparticles was obtained from FTIR studies. The XRD and HR-TEM investigations clearly demonstrated the crystalline nature of the nanoparticles. From the TEM images, the silver nanoparticles were found to be spherical and of nearly uniform size with an average diameter of 18.2 ± 0.97 nm. The nanoparticles showed excellent catalytic activity in the degradation of methyl orange and rhodamine B by NaBH 4

Spectroscopic investigation on the chemical forms of Cu during the synthesis of zeolite X at low temperature

International Nuclear Information System (INIS)

Terzano, Roberto; Spagnuolo, Matteo; Medici, Luca; Tateo, Fabio; Vekemans, Bart; Janssens, Koen; Ruggiero, Pacifico

2006-01-01

The direct synthesis of zeolites in polluted soils has proved to be a promising process for the stabilization of metals inside these minerals. Nevertheless, more detailed information about this process is still needed in order to better foresee the fate of metals in treated soils. In this work, zeolite X has been synthesized under alkaline conditions in an aqueous solution containing 2500 mg kg -1 of Cu, starting from Na silicate and Al hydroxide at 60 deg. C. Aluminium, Si and Cu concentrations in the aqueous phase, during zeolite synthesis, were measured over a period of 160 h. The solid products have been characterized over time by XRD, SEM-EDX, ESR, FT-IR, and synchrotron radiation X-ray microbeam absorption near edge structure (μ-XANES) and extended X-ray absorption fine structure (μ-EXAFS) spectroscopy. It appears that the marked reduction of Cu concentration in solution is not only due to a simple precipitation effect, but also to processes connected with the formation of zeolite X which could entrap, inside its porous structure, nano- or micro-occlusions of precipitated Cu hydroxides and/or oxides. In addition, EXAFS observations strengthen the hypothesis of the presence of different Cu phases even at a short-range molecular level and suggest that some of these occlusions could be even bound to the zeolite framework. The results suggest that zeolite formation could be used to reduce the availability of metals in polluted soils

Principles of spectroscopic diagnostics of a plasma with oscillating electric fields

International Nuclear Information System (INIS)

Oks, E.A.

1986-01-01

Three types of main principles of spectroscopic diagnosis of the plasma with quasimonochromatic electric fields (QEF) are considered. Principles based on the effects intersectionally depending on the parameters of QEF and the plasma medium are considered. Occurrence of depressions or dips in the profiles of spectral lines is the most important effect among others. Principles based on the nonlinear theory of plasma and laser sattelites of spectral lines as well as laser-spectroscopic diagnosis of QEF in the plasma are considered

THE GALACTIC O-STAR SPECTROSCOPIC SURVEY (GOSSS). III. 142 ADDITIONAL O-TYPE SYSTEMS

International Nuclear Information System (INIS)

Apellániz, J. Maíz; Sota, A.; Alfaro, E. J.; Arias, J. I.; Barbá, R. H.; Walborn, N. R.; Simón-Díaz, S.; Herrero, A.; Negueruela, I.; Marco, A.; Leão, J. R. S.; Gamen, R. C.

2016-01-01

This is the third installment of the Galactic O-Star Spectroscopic Survey (GOSSS), a massive spectroscopic survey of Galactic O stars, based on new homogeneous, high signal-to-noise ratio, R  ∼ 2500 digital observations selected from the Galactic O-Star Catalog. In this paper, we present 142 additional stellar systems with O stars from both hemispheres, bringing the total of O-type systems published within the project to 590. Among the new objects, there are 20 new O stars. We also identify 11 new double-lined spectroscopic binaries, 6 of which are of O+O type and 5 of O+B type, and an additional new tripled-lined spectroscopic binary of O+O+B type. We also revise some of the previous GOSSS classifications, present some egregious examples of stars erroneously classified as O-type in the past, introduce the use of luminosity class IV at spectral types O4-O5.5, and adapt the classification scheme to the work of Arias et al.

THE GALACTIC O-STAR SPECTROSCOPIC SURVEY (GOSSS). III. 142 ADDITIONAL O-TYPE SYSTEMS

Energy Technology Data Exchange (ETDEWEB)

Apellániz, J. Maíz [Centro de Astrobiología, CSIC-INTA, campus ESAC, camino bajo del castillo s/n, E-28 692 Madrid (Spain); Sota, A.; Alfaro, E. J. [Instituto de Astrofísica de Andalucía-CSIC, Glorieta de la Astronomía s/n, E-18 008 Granada (Spain); Arias, J. I.; Barbá, R. H. [Departamento de Física, Universidad de La Serena, Av. Cisternas 1200 Norte, La Serena (Chile); Walborn, N. R. [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21 218 (United States); Simón-Díaz, S.; Herrero, A. [Instituto de Astrofísica de Canarias, E-38 200 La Laguna, Tenerife (Spain); Negueruela, I.; Marco, A. [DFISTS, EPS, Universidad de Alicante, carretera San Vicente del Raspeig s/n, E-03 690 Alicante (Spain); Leão, J. R. S. [Univ. Federal do Rio Grande do Norte—UFRN, Caixa Postal 1524, CEP 59 078-970, Natal—RN (Brazil); Gamen, R. C., E-mail: jmaiz@cab.inta-csic.es [Instituto de Astrofísica de La Plata (CONICET, UNLP), Paseo del Bosque s/n, 1900 La Plata (Argentina)

2016-05-01

This is the third installment of the Galactic O-Star Spectroscopic Survey (GOSSS), a massive spectroscopic survey of Galactic O stars, based on new homogeneous, high signal-to-noise ratio, R  ∼ 2500 digital observations selected from the Galactic O-Star Catalog. In this paper, we present 142 additional stellar systems with O stars from both hemispheres, bringing the total of O-type systems published within the project to 590. Among the new objects, there are 20 new O stars. We also identify 11 new double-lined spectroscopic binaries, 6 of which are of O+O type and 5 of O+B type, and an additional new tripled-lined spectroscopic binary of O+O+B type. We also revise some of the previous GOSSS classifications, present some egregious examples of stars erroneously classified as O-type in the past, introduce the use of luminosity class IV at spectral types O4-O5.5, and adapt the classification scheme to the work of Arias et al.

Synthesis, characterization and sup 23 Na NMR shift studies of a novel dysprosium(III) crown ether texaphyrin

Energy Technology Data Exchange (ETDEWEB)

Sessler, J.L.; Mody, T.D. (Texas Univ., Austin, TX (United States). Dept. of Chemistry); Ramasamy, R.; Sherry, A.D. (Texas Univ., Dallas, TX (United States))

1992-05-01

The synthesis and characterization of a novel dysprosium(III) crown-ether texaphyrin (Dy(BCTxp)){sup 2+} is reported. This complex was designed to serve as a ditopic chelate for both dysprosium(III) and sodium cations. {sup 23}Sodium NMR spectroscopic studies indicates that titration of Na{sup +} with increasing concentrations of (Dy(BCTxp)){sup 2+} results in a shift toward higher frequency and gives a net hyperfine shift of 0.86 ppm. Sodium complexation is taking place into the crown subunit in (Dy(BCTxp)){sup 2+} and the degree of complexation is not reduced substantially by the positive charge on the dysprosium(III) portion of this binucleating system.

Spectroscopic studies of pulsed-power plasmas

International Nuclear Information System (INIS)

Maron, Y.; Arad, R.; Dadusc, G.; Davara, G.; Duvall, R.E.; Fisher, V.; Foord, M.E.; Fruchtman, A.; Gregorian, L.; Krasik, Ya.

1993-01-01

Recently developed spectroscopic diagnostic techniques are used to investigate the plasma behavior in a Magnetically Insulated Ion Diode, a Plasma Opening Switch, and a gas-puffed Z-pinch. Measurements with relatively high spectral, temporal, and spatial resolutions are performed. The particle velocity and density distributions within a few tens of microns from the dielectric-anode surface are observed using laser spectroscopy. Collective fluctuating electric fields in the plasma are inferred from anisotropic Stark broadening. For the Plasma Opening Switch experiment, a novel gaseous plasma source was developed which is mounted inside the high-voltage inner conductor. The properties of this source, together with spectroscopic observations of the electron density and particle velocities of the injected plasma, are described. Emission line intensities and spectral profiles give the electron kinetic energies during the switch operation and the ion velocity distributions. Secondary plasma ejection from the electrodes is also studied. In the Z-pinch experiment, spectral emission-line profiles are studied during the implosion phase. Doppler line shifts and widths yield the radial velocity distributions for various charge states in various regions of the plasma. Effects of plasma ejection from the cathode are also studied

The HITRAN 2004 molecular spectroscopic database

Energy Technology Data Exchange (ETDEWEB)

Rothman, L.S. [Harvard-Smithsonian Center for Astrophysics, Atomic and Molecular Physics Division, Cambridge, MA 02138 (United States)]. E-mail: lrothman@cfa.harvard.edu; Jacquemart, D. [Harvard-Smithsonian Center for Astrophysics, Atomic and Molecular Physics Division, Cambridge, MA 02138 (United States); Barbe, A. [Universite de Reims-Champagne-Ardenne, Groupe de Spectrometrie Moleculaire et Atmospherique, 51062 Reims (France)] (and others)

2005-12-01

This paper describes the status of the 2004 edition of the HITRAN molecular spectroscopic database. The HITRAN compilation consists of several components that serve as input for radiative transfer calculation codes: individual line parameters for the microwave through visible spectra of molecules in the gas phase; absorption cross-sections for molecules having dense spectral features, i.e., spectra in which the individual lines are unresolvable; individual line parameters and absorption cross-sections for bands in the ultra-violet; refractive indices of aerosols; tables and files of general properties associated with the database; and database management software. The line-by-line portion of the database contains spectroscopic parameters for 39 molecules including many of their isotopologues. The format of the section of the database on individual line parameters of HITRAN has undergone the most extensive enhancement in almost two decades. It now lists the Einstein A-coefficients, statistical weights of the upper and lower levels of the transitions, a better system for the representation of quantum identifications, and enhanced referencing and uncertainty codes. In addition, there is a provision for making corrections to the broadening of line transitions due to line mixing.

The HITRAN 2004 molecular spectroscopic database

International Nuclear Information System (INIS)

Rothman, L.S.; Jacquemart, D.; Barbe, A.

2005-01-01

This paper describes the status of the 2004 edition of the HITRAN molecular spectroscopic database. The HITRAN compilation consists of several components that serve as input for radiative transfer calculation codes: individual line parameters for the microwave through visible spectra of molecules in the gas phase; absorption cross-sections for molecules having dense spectral features, i.e., spectra in which the individual lines are unresolvable; individual line parameters and absorption cross-sections for bands in the ultra-violet; refractive indices of aerosols; tables and files of general properties associated with the database; and database management software. The line-by-line portion of the database contains spectroscopic parameters for 39 molecules including many of their isotopologues. The format of the section of the database on individual line parameters of HITRAN has undergone the most extensive enhancement in almost two decades. It now lists the Einstein A-coefficients, statistical weights of the upper and lower levels of the transitions, a better system for the representation of quantum identifications, and enhanced referencing and uncertainty codes. In addition, there is a provision for making corrections to the broadening of line transitions due to line mixing

Convolutional neural networks for vibrational spectroscopic data analysis.

Science.gov (United States)

Acquarelli, Jacopo; van Laarhoven, Twan; Gerretzen, Jan; Tran, Thanh N; Buydens, Lutgarde M C; Marchiori, Elena

2017-02-15

In this work we show that convolutional neural networks (CNNs) can be efficiently used to classify vibrational spectroscopic data and identify important spectral regions. CNNs are the current state-of-the-art in image classification and speech recognition and can learn interpretable representations of the data. These characteristics make CNNs a good candidate for reducing the need for preprocessing and for highlighting important spectral regions, both of which are crucial steps in the analysis of vibrational spectroscopic data. Chemometric analysis of vibrational spectroscopic data often relies on preprocessing methods involving baseline correction, scatter correction and noise removal, which are applied to the spectra prior to model building. Preprocessing is a critical step because even in simple problems using 'reasonable' preprocessing methods may decrease the performance of the final model. We develop a new CNN based method and provide an accompanying publicly available software. It is based on a simple CNN architecture with a single convolutional layer (a so-called shallow CNN). Our method outperforms standard classification algorithms used in chemometrics (e.g. PLS) in terms of accuracy when applied to non-preprocessed test data (86% average accuracy compared to the 62% achieved by PLS), and it achieves better performance even on preprocessed test data (96% average accuracy compared to the 89% achieved by PLS). For interpretability purposes, our method includes a procedure for finding important spectral regions, thereby facilitating qualitative interpretation of results. Copyright © 2016 Elsevier B.V. All rights reserved.

Development and validation of a spectroscopic method for the ...

African Journals Online (AJOL)

Development and validation of a spectroscopic method for the simultaneous analysis of ... advanced analytical methods such as high pressure liquid ..... equipment. DECLARATIONS ... high-performance liquid chromatography. J Chromatogr.

Spectroscopic properties of Pr -doped erbium oxalate crystals

Indian Academy of Sciences (India)

Spectroscopic properties of praseodymium ions-doped erbium oxalate ... solution with specific gravity 1.04 g/cm3 was mixed homogeneously with 0.5 M oxalic ... of concentrated nitric acid were transferred carefully and gently through the wall ...

Normal-incidence spectroscopic ellipsometry for critical dimension monitoring

International Nuclear Information System (INIS)

Huang, Hsu-Ting; Kong, Wei; Terry, Fred Lewis

2001-01-01

In this letter, we show that normal-incidence spectroscopic ellipsometry can be used for high-accuracy topography measurements on surface relief gratings. We present both experimental and theoretical results which show that spectroscopic ellipsometry or reflectance-difference spectroscopy at near-normal incidence coupled with vector diffraction theory for data analysis is capable of high-accuracy critical dimension (CD), feature height, and sidewall angle measurements in the extreme submicron regime. Quantitative comparisons of optical and cross-sectional scanning electron microscopy (SEM) topography measurements from a number of 350 nm line/space reactive-ion-etched Si gratings demonstrate the strong potential for in situ etching monitoring. This technique can be used for both ex situ and in situ applications and has the potential to replace the use of CD-SEM measurements in some applications. [copyright] 2001 American Institute of Physics

Spectroscopic properties for identifying sapphire samples from Ban Bo Kaew, Phrae Province, Thailand

Science.gov (United States)

Mogmued, J.; Monarumit, N.; Won-in, K.; Satitkune, S.

2017-09-01

Gemstone commercial is a high revenue for Thailand especially ruby and sapphire. Moreover, Phrae is a potential gem field located in the northern part of Thailand. The studies of spectroscopic properties are mainly to identify gemstone using advanced techniques (e.g. UV-Vis-NIR spectrophotometry, FTIR spectrometry and Raman spectroscopy). Typically, UV-Vis-NIR spectrophotometry is a technique to study the cause of color in gemstones. FTIR spectrometry is a technique to study the functional groups in gem-materials. Raman pattern can be applied to identify the mineral inclusions in gemstones. In this study, the natural sapphires from Ban Bo Kaew were divided into two groups based on colors including blue and green. The samples were analyzed by UV-Vis-NIR spectrophotometer, FTIR spectrometer and Raman spectroscope for studying spectroscopic properties. According to UV-Vis-NIR spectra, the blue sapphires show higher Fe3+/Ti4+ and Fe2+/Fe3+ absorption peaks than those of green sapphires. Otherwise, green sapphires display higher Fe3+/Fe3+ absorption peaks than blue sapphires. The FTIR spectra of both blue and green sapphire samples show the absorption peaks of -OH,-CH and CO2. The mineral inclusions such as ferrocolumbite and rutile in sapphires from this area were observed by Raman spectroscope. The spectroscopic properties of sapphire samples from Ban Bo Kaew, Phrae Province, Thailand are applied to be the specific evidence for gemstone identification.

Spectroscopic and structural study of novel interaction product of pyrrolidine-2-thione with molecular iodine. Presumable mechanisms of oxidation

Science.gov (United States)

Chernov'yants, Margarita S.; Burykin, Igor V.; Starikova, Zoya A.; Tereznikov, Alexander Yu.; Kolesnikova, Tatiana S.

2013-09-01

Synthesis, spectroscopic and structural characterization of novel interaction product of pyrrolidine-2-thione with molecular iodine is reported. The ability of pyrrolidine-2-thione to form the outer-sphere charge-transfer complex C4H7NS·I2 with iodine molecule in dilute chloroform solution has been studied by UV/vis spectroscopy. Oxidative desulfurization promotes ring fusion of two pyrrolidine-2-thione molecules. The product of iodine induced oxidative desulfurization has been studied by X-ray diffraction method. The crystal structure of the reaction product is formed by 5-(2-thioxopyrrolidine-1-yl)-3,4-dihydro-2H-pyrrolium (C8H13N2S+) cations and pentaiodide anions I5-, which are linked by the intermolecular I⋯Hsbnd C and I⋯C close contacts. The angular pentaiodide anions can be considered as structures formed by coordination of two iodine molecules to the iodide ion (type 1) or by the coordination of iodine molecule to the triiodide ion (type 2).

Spectroscopic study

International Nuclear Information System (INIS)

Flores, M.; Rodriguez, R.; Arroyo, R.

1999-01-01

This work is focused about the spectroscopic properties of a polymer material which consists of Polyacrylic acid (Paa) doped at different concentrations of Europium ions (Eu 3+ ). They show that to stay chemically joined with the polymer by a study of Nuclear Magnetic Resonance (NMR) of 1 H, 13 C and Fourier Transform Infrared Spectroscopy (Ft-IR) they present changes in the intensity of signals, just as too when this material is irradiated at λ = 394 nm. In according with the results obtained experimentally in this type of materials it can say that is possible to unify chemically the polymer with this type of cations, as well as, varying the concentration of them, since that these are distributed homogeneously inside the matrix maintaining its optical properties. These materials can be obtained more quickly and easy in solid or liquid phase and they have the best conditions for to make a quantitative analysis. (Author)

Enhancing forensic science with spectroscopic imaging

Science.gov (United States)

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

Synthesis of gold nanochains via photoactivation technique and their catalytic applications.

Science.gov (United States)

Sinha, Arun Kumar; Basu, Mrinmoyee; Sarkar, Sougata; Pradhan, Mukul; Pal, Tarasankar

2013-05-15

The article reports a simple photoactivation technique for the synthesis of chain like assembly of spherical Au nanocrystals using a nontoxic biochemical, β-cyclodextrin under ~365 nm UV-light irradiation. Under UV irradiation, β-cyclodextrin acts as a reducing as well as capping agent and eventually becomes a stabilizing linker for Au nanoparticles. The UV-visible spectroscopy, transmission electron microscopy (TEM), selected area electron diffraction (SAED), X-ray diffraction (XRD), and X-ray photoelectron spectroscopic techniques are employed to systematically characterize the Au nanochains. Additionally, it is shown that the Au nanocrystals act as an effective catalyst for the reduction in nitrobenzene to aniline and methylene blue to leuco methylene blue in presence of suitable reducing agent. The catalytic reduction reactions and kinetic parameters are evaluated from UV-visible spectroscopy. Copyright © 2013 Elsevier Inc. All rights reserved.

Two-directional synthesis as a tool for diversity-oriented synthesis: Synthesis of alkaloid scaffolds

Directory of Open Access Journals (Sweden)

Kieron M. G. O’Connell

2012-06-01

Full Text Available Two-directional synthesis represents an ideal strategy for the rapid elaboration of simple starting materials and their subsequent transformation into complex molecular architectures. As such, it is becoming recognised as an enabling technology for diversity-oriented synthesis. Herein, we provide a thorough account of our work combining two-directional synthesis with diversity-oriented synthesis, with particular reference to the synthesis of polycyclic alkaloid scaffolds.

Photoelectric Radial Velocities, Paper XIX Additional Spectroscopic ...

Indian Academy of Sciences (India)

ian velocity curve that does justice to the measurements, but it cannot be expected to have much predictive power. Key words. Stars: late-type—stars: radial velocities—spectroscopic binaries—orbits. 0. Preamble. The 'Redman K stars' are a lot of seventh-magnitude K stars whose radial velocities were first observed by ...

Raman Spectroscopic Imaging of the Whole Ciona intestinalis Embryo during Development

Science.gov (United States)

Nakamura, Mitsuru J.; Hotta, Kohji; Oka, Kotaro

2013-01-01

Intracellular composition and the distribution of bio-molecules play central roles in the specification of cell fates and morphogenesis during embryogenesis. Consequently, investigation of changes in the expression and distribution of bio-molecules, especially mRNAs and proteins, is an important challenge in developmental biology. Raman spectroscopic imaging, a non-invasive and label-free technique, allows simultaneous imaging of the intracellular composition and distribution of multiple bio-molecules. In this study, we explored the application of Raman spectroscopic imaging in the whole Ciona intestinalis embryo during development. Analysis of Raman spectra scattered from C. intestinalis embryos revealed a number of localized patterns of high Raman intensity within the embryo. Based on the observed distribution of bio-molecules, we succeeded in identifying the location and structure of differentiated muscle and endoderm within the whole embryo, up to the tailbud stage, in a label-free manner. Furthermore, during cell differentiation, we detected significant differences in cell state between muscle/endoderm daughter cells and daughter cells with other fates that had divided from the same mother cells; this was achieved by focusing on the Raman intensity of single Raman bands at 1002 or 1526 cm−1, respectively. This study reports the first application of Raman spectroscopic imaging to the study of identifying and characterizing differentiating tissues in a whole chordate embryo. Our results suggest that Raman spectroscopic imaging is a feasible label-free technique for investigating the developmental process of the whole embryo of C. intestinalis. PMID:23977129

SPECTROSCOPIC AND INTERFEROMETRIC MEASUREMENTS OF NINE K GIANT STARS

Energy Technology Data Exchange (ETDEWEB)

Baines, Ellyn K. [Remote Sensing Division, Naval Research Laboratory, 4555 Overlook Avenue SW, Washington, DC 20375 (United States); Döllinger, Michaela P. [Max-Planck-Institut für Astronomie, Königstuhl 17, D-69117 Heidelberg (Germany); Guenther, Eike W.; Hatzes, Artie P. [Thüringer Landessternwarte Tautenburg, Sternwarte 5, D-07778 Tautenburg (Germany); Hrudkovu, Marie [Isaac Newton Group of Telescopes, Apartado de Correos 321, E-387 00 Santa Cruz de la Palma, Canary Islands (Spain); Belle, Gerard T. van, E-mail: ellyn.baines@nrl.navy.mil [Lowell Observatory, Flagstaff, AZ 86001 (United States)

2016-09-01

We present spectroscopic and interferometric measurements for a sample of nine K giant stars. These targets are of particular interest because they are slated for stellar oscillation observations. Our improved parameters will directly translate into reduced errors in the final masses for these stars when interferometric radii and asteroseismic densities are combined. Here, we determine each star’s limb-darkened angular diameter, physical radius, luminosity, bolometric flux, effective temperature, surface gravity, metallicity, and mass. When we compare our interferometric and spectroscopic results, we find no systematic offsets in the diameters and the values generally agree within the errors. Our interferometric temperatures for seven of the nine stars are hotter than those determined from spectroscopy with an average difference of about 380 K.

THE TIME DOMAIN SPECTROSCOPIC SURVEY: VARIABLE SELECTION AND ANTICIPATED RESULTS

Energy Technology Data Exchange (ETDEWEB)

Morganson, Eric; Green, Paul J. [Harvard Smithsonian Center for Astrophysics, 60 Garden St, Cambridge, MA 02138 (United States); Anderson, Scott F.; Ruan, John J. [Department of Astronomy, University of Washington, Box 351580, Seattle, WA 98195 (United States); Myers, Adam D. [Department of Physics and Astronomy, University of Wyoming, Laramie, WY 82071 (United States); Eracleous, Michael; Brandt, William Nielsen [Department of Astronomy and Astrophysics, 525 Davey Laboratory, The Pennsylvania State University, University Park, PA 16802 (United States); Kelly, Brandon [Department of Physics, Broida Hall, University of California, Santa Barbara, CA 93106-9530 (United States); Badenes, Carlos [Department of Physics and Astronomy and Pittsburgh Particle Physics, Astrophysics and Cosmology Center (PITT PACC), University of Pittsburgh, 3941 O’Hara St, Pittsburgh, PA 15260 (United States); Bañados, Eduardo [Max-Planck-Institut für Astronomie, Königstuhl 17, D-69117 Heidelberg (Germany); Blanton, Michael R. [Center for Cosmology and Particle Physics, Department of Physics, New York University, 4 Washington Place, New York, NY 10003 (United States); Bershady, Matthew A. [Department of Astronomy, University of Wisconsin, 475 N. Charter St., Madison, WI 53706 (United States); Borissova, Jura [Instituto de Física y Astronomía, Universidad de Valparaíso, Av. Gran Bretaña 1111, Playa Ancha, Casilla 5030, and Millennium Institute of Astrophysics (MAS), Santiago (Chile); Burgett, William S. [GMTO Corp, Suite 300, 251 S. Lake Ave, Pasadena, CA 91101 (United States); Chambers, Kenneth, E-mail: emorganson@cfa.harvard.edu [Institute for Astronomy, University of Hawaii at Manoa, Honolulu, HI 96822 (United States); and others

2015-06-20

We present the selection algorithm and anticipated results for the Time Domain Spectroscopic Survey (TDSS). TDSS is an Sloan Digital Sky Survey (SDSS)-IV Extended Baryon Oscillation Spectroscopic Survey (eBOSS) subproject that will provide initial identification spectra of approximately 220,000 luminosity-variable objects (variable stars and active galactic nuclei across 7500 deg{sup 2} selected from a combination of SDSS and multi-epoch Pan-STARRS1 photometry. TDSS will be the largest spectroscopic survey to explicitly target variable objects, avoiding pre-selection on the basis of colors or detailed modeling of specific variability characteristics. Kernel Density Estimate analysis of our target population performed on SDSS Stripe 82 data suggests our target sample will be 95% pure (meaning 95% of objects we select have genuine luminosity variability of a few magnitudes or more). Our final spectroscopic sample will contain roughly 135,000 quasars and 85,000 stellar variables, approximately 4000 of which will be RR Lyrae stars which may be used as outer Milky Way probes. The variability-selected quasar population has a smoother redshift distribution than a color-selected sample, and variability measurements similar to those we develop here may be used to make more uniform quasar samples in large surveys. The stellar variable targets are distributed fairly uniformly across color space, indicating that TDSS will obtain spectra for a wide variety of stellar variables including pulsating variables, stars with significant chromospheric activity, cataclysmic variables, and eclipsing binaries. TDSS will serve as a pathfinder mission to identify and characterize the multitude of variable objects that will be detected photometrically in even larger variability surveys such as Large Synoptic Survey Telescope.

Synthesis and Doping of Ligand-Protected Atomically-Precise Metal Nanoclusters

KAUST Repository

Aljuhani, Maha A.

2016-05-01

Rapidly expanding research in nanotechnology has led to exciting progress in a versatile array of applications from medical diagnostics to catalysis. This success resulted from the manipulation of the desired properties of nanomaterials by controlling their size, shape, and composition. Among the most thriving areas of research about nanoparticle is the synthesis and doping of the ligand-protected atomically-precise metal nanoclusters. In this thesis, we developed three different novel metal nanoclusters, such as doped Ag29 with five gold (Au) atoms leading to enhance its quantum yield with remarkable stability. We also developed half-doped (alloyed) cluster of Ni6 nanocluster with molybdenum (Mo). This enabled enhanced stability and better catalytic activity. The third metal nanocluster that we synthesized was Au28 nanocluster by using di-thiolate as the ligand stabilizer instead of mono-thiolate. The new metal clusters obtained have been characterized by spectroscopic, electrochemical and crystallographic methods.

ePESSTO spectroscopic classification of the candidate TDE XMMSL2 J140446.9-251135

Science.gov (United States)

Taubenberger, S.; Floers, A.; Vogl, C.; Benetti, S.; Pastorello, A.; Cappellaro, E.; Anderson, J.; Gromadzki, M.; Onori, F.; Kostrzewa-Rutkowska, Z.; Jonker, P.; Leloudas, G.; Inserra, C.; Kankare, E.; Maguire, K.; Smartt, S. J.; Yaron, O.; Young, D.

2018-03-01

ePESSTO, the extended Public ESO Spectroscopic Survey for Transient Objects (see Smartt et al. 2015, A & A, 579, 40; http://www.pessto.org ), reports the following spectroscopic observation of the new X-ray source XMMSL2 J140446.9-251135 in the galaxy 2MASX 14044671-2511433 (ATel #11394).

Synthesis and characterization of CdS/PVA nanocomposite films

Science.gov (United States)

Wang, Hongmei; Fang, Pengfei; Chen, Zhe; Wang, Shaojie

2007-08-01

A series CdS/PVA nanocomposite films with different amount of Cd salt have been prepared by means of the in situ synthesis method via the reaction of Cd 2+-dispersed poly vinyl-alcohol (PVA) with H 2S. The as-prepared films were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), ultraviolet-visible (UV-vis) absorption, photoluminescence (PL) spectra, Fourier transform infrared spectroscope (FTIR) and thermogravimetric analysis (TGA). The XRD results indicated the formation of CdS nanoparticles with hexagonal phase in the PVA matrix. The primary FTIR spectra of CdS/PVA nanocomposite in different processing stages have been discussed. The vibrational absorption peak of Cd sbnd S bond at 405 cm -1 was observed, which further testified the generation of CdS nanoparticles. The TGA results showed incorporation of CdS nanoparticles significantly altered the thermal properties of PVA matrix. The photoluminescence and UV-vis spectroscopy revealed that the CdS/PVA films showed quantum confinement effect.

Synthesis and characterization of CdS/PVA nanocomposite films

International Nuclear Information System (INIS)

Wang Hongmei; Fang Pengfei; Chen Zhe; Wang Shaojie

2007-01-01

A series CdS/PVA nanocomposite films with different amount of Cd salt have been prepared by means of the in situ synthesis method via the reaction of Cd 2+ -dispersed poly vinyl-alcohol (PVA) with H 2 S. The as-prepared films were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), ultraviolet-visible (UV-vis) absorption, photoluminescence (PL) spectra, Fourier transform infrared spectroscope (FTIR) and thermogravimetric analysis (TGA). The XRD results indicated the formation of CdS nanoparticles with hexagonal phase in the PVA matrix. The primary FTIR spectra of CdS/PVA nanocomposite in different processing stages have been discussed. The vibrational absorption peak of Cd-S bond at 405 cm -1 was observed, which further testified the generation of CdS nanoparticles. The TGA results showed incorporation of CdS nanoparticles significantly altered the thermal properties of PVA matrix. The photoluminescence and UV-vis spectroscopy revealed that the CdS/PVA films showed quantum confinement effect

Enhanced active aluminum content and thermal behaviour of nano-aluminum particles passivated during synthesis using thermal plasma route

International Nuclear Information System (INIS)

Mathe, Vikas L.; Varma, Vijay; Raut, Suyog; Nandi, Amiya Kumar; Pant, Arti; Prasanth, Hima; Pandey, R.K.; Bhoraskar, Sudha V.; Das, Asoka K.

2016-01-01

Graphical abstract: - Highlights: • Synthesis of nano crystalline Al (nAl) using DC thermal plasma reactor. • In situ passivation of nAl by palmitic acid and air. • Enhanced active aluminum content obtained for palmitic acid passivated nAl. • Palmitic acid passivated nAl are quite stable in humid atmospheres. - Abstract: Here, we report synthesis and in situ passivation of aluminum nanoparticles using thermal plasma reactor. Both air and palmitc acid passivation was carried out during the synthesis in the thermal plasma reactor. The passivated nanoparticles have been characterized for their structural and morphological properties using X-ray diffraction (XRD) and transmission electron microscopy (TEM) techniques. In order to understand nature of passivation vibrational spectroscopic analysis have been carried out. The enhancement in active aluminum content and shelf life for a palmitic acid passivated nano-aluminum particles in comparison to the air passivated samples and commercially available nano Al powder (ALEX) has been observed. Thermo-gravimetric analysis was used to estimate active aluminum content of all the samples under investigation. In addition cerimetric back titration method was also used to estimate AAC and the shelf life of passivated aluminum particles. Structural, microstructural and thermogravomateric analysis of four year aged passivated sample also depicts effectiveness of palmitic acid passivation.

Enhanced active aluminum content and thermal behaviour of nano-aluminum particles passivated during synthesis using thermal plasma route

Energy Technology Data Exchange (ETDEWEB)

Mathe, Vikas L., E-mail: vlmathe@physics.unipune.ac.in [Department of Physics, Savitribai Phule Pune University, Pune 411007, Maharashtra (India); Varma, Vijay; Raut, Suyog [Department of Physics, Savitribai Phule Pune University, Pune 411007, Maharashtra (India); Nandi, Amiya Kumar; Pant, Arti; Prasanth, Hima; Pandey, R.K. [High Energy Materials Research Lab, Sutarwadi, Pune 411021, Maharashtra (India); Bhoraskar, Sudha V. [Department of Physics, Savitribai Phule Pune University, Pune 411007, Maharashtra (India); Das, Asoka K. [Utkal University, VaniVihar, Bhubaneswar, Odisha 751004 (India)

2016-04-15

Graphical abstract: - Highlights: • Synthesis of nano crystalline Al (nAl) using DC thermal plasma reactor. • In situ passivation of nAl by palmitic acid and air. • Enhanced active aluminum content obtained for palmitic acid passivated nAl. • Palmitic acid passivated nAl are quite stable in humid atmospheres. - Abstract: Here, we report synthesis and in situ passivation of aluminum nanoparticles using thermal plasma reactor. Both air and palmitc acid passivation was carried out during the synthesis in the thermal plasma reactor. The passivated nanoparticles have been characterized for their structural and morphological properties using X-ray diffraction (XRD) and transmission electron microscopy (TEM) techniques. In order to understand nature of passivation vibrational spectroscopic analysis have been carried out. The enhancement in active aluminum content and shelf life for a palmitic acid passivated nano-aluminum particles in comparison to the air passivated samples and commercially available nano Al powder (ALEX) has been observed. Thermo-gravimetric analysis was used to estimate active aluminum content of all the samples under investigation. In addition cerimetric back titration method was also used to estimate AAC and the shelf life of passivated aluminum particles. Structural, microstructural and thermogravomateric analysis of four year aged passivated sample also depicts effectiveness of palmitic acid passivation.

Spectroscopic orbit for HDE 245770 A0535+26

International Nuclear Information System (INIS)

Hutchings, J.B.

1984-01-01

Optical spectroscopic data are examined using the X-ray intensity period of 111 days. Optical and X-ray pulse-timing orbit parameters agree well and indicate an eccentricity of approximately 0.3. Masses of the stars and periastron effects are discussed. 6 references

Isospin asymmetry dependence of the α spectroscopic factor for heavy nuclei

International Nuclear Information System (INIS)

Seif, W. M.; Shalaby, M.; Alrakshy, M. F.

2011-01-01

Both the valence nucleons (holes) and the isospin asymmetry dependencies of the preformation probability of an α-cluster inside parents radioactive nuclei are investigated. The calculations are employed in the framework of the density-dependent cluster model of an α-decay process for the even-even spherical parents nuclei with protons number around the closed shell Z 0 = 82 and neutrons number around the closed shells Z 0 = 82 and Z 0 = 126. The microscopic α-daughter nuclear interaction potential is calculated in the framework of the Hamiltonian energy density approach based on the SLy4 Skyrme-like effective interaction. Also, the calculations based on the realistic effective M3Y-Paris nucleon-nucleon force have been used to confirm the results. The calculations then proceed to find the assault frequency and the α penetration probability within the WKB approximation. The half-lives of the different mentioned α decays are then determined and have been used in turn to find the α spectroscopic factor. We found that the spectroscopic factor increases with increasing the isospin asymmetry of the parent nuclei if they have valence protons and neutrons. When the parent nuclei have neutron or proton holes in addition to the valence protons or neutrons, then the spectroscopic factor is found to decrease with increasing isospin asymmetry. The obtained results show also that the deduced spectroscopic factors follow individual linear behaviors as a function of the multiplication of the valence proton (N p ) and neutron (N n ) numbers. These linear dependencies are correlated with the closed shells core (Z 0 ,N 0 ). The same individual linear behaviors are obtained as a function of the multiplication of N p N n and the isospin asymmetry parameter, N p N n I. Moreover, the whole deduced spectroscopic factors are found to exhibit a nearly general linear trend with the function N p N n /(Z 0 +N 0 ).

Spectroscopic diagnostics and measurements at Jet

International Nuclear Information System (INIS)

Giannella, R.

1994-01-01

A concise review is presented of activity in the field spectroscopic diagnostic at JET during the latest few years. Together with a description of instruments, examples are given of the measurements conducted with these systems and some experimental result obtained with such activity are outlined. Emphasis is also given to the upgrading of existing apparatuses and the construction of new diagnostics ahead of the next experimental phase. 48 refs., 5 figs

Cosmic homogeneity: a spectroscopic and model-independent measurement

Science.gov (United States)

Gonçalves, R. S.; Carvalho, G. C.; Bengaly, C. A. P., Jr.; Carvalho, J. C.; Bernui, A.; Alcaniz, J. S.; Maartens, R.

2018-03-01

Cosmology relies on the Cosmological Principle, i.e. the hypothesis that the Universe is homogeneous and isotropic on large scales. This implies in particular that the counts of galaxies should approach a homogeneous scaling with volume at sufficiently large scales. Testing homogeneity is crucial to obtain a correct interpretation of the physical assumptions underlying the current cosmic acceleration and structure formation of the Universe. In this letter, we use the Baryon Oscillation Spectroscopic Survey to make the first spectroscopic and model-independent measurements of the angular homogeneity scale θh. Applying four statistical estimators, we show that the angular distribution of galaxies in the range 0.46 < z < 0.62 is consistent with homogeneity at large scales, and that θh varies with redshift, indicating a smoother Universe in the past. These results are in agreement with the foundations of the standard cosmological paradigm.

Controllable synthesis of molybdenum tungsten disulfide alloy for vertically composition-controlled multilayer

Science.gov (United States)

Song, Jeong-Gyu; Ryu, Gyeong Hee; Lee, Su Jeong; Sim, Sangwan; Lee, Chang Wan; Choi, Taejin; Jung, Hanearl; Kim, Youngjun; Lee, Zonghoon; Myoung, Jae-Min; Dussarrat, Christian; Lansalot-Matras, Clement; Park, Jusang; Choi, Hyunyong; Kim, Hyungjun

2015-01-01

The effective synthesis of two-dimensional transition metal dichalcogenides alloy is essential for successful application in electronic and optical devices based on a tunable band gap. Here we show a synthesis process for Mo1−xWxS2 alloy using sulfurization of super-cycle atomic layer deposition Mo1−xWxOy. Various spectroscopic and microscopic results indicate that the synthesized Mo1−xWxS2 alloys have complete mixing of Mo and W atoms and tunable band gap by systematically controlled composition and layer number. Based on this, we synthesize a vertically composition-controlled (VCC) Mo1−xWxS2 multilayer using five continuous super-cycles with different cycle ratios for each super-cycle. Angle-resolved X-ray photoemission spectroscopy, Raman and ultraviolet–visible spectrophotometer results reveal that a VCC Mo1−xWxS2 multilayer has different vertical composition and broadband light absorption with strong interlayer coupling within a VCC Mo1−xWxS2 multilayer. Further, we demonstrate that a VCC Mo1−xWxS2 multilayer photodetector generates three to four times greater photocurrent than MoS2- and WS2-based devices, owing to the broadband light absorption. PMID:26204328

A Fully Customized Baseline Removal Framework for Spectroscopic Applications.

Science.gov (United States)

Giguere, Stephen; Boucher, Thomas; Carey, C J; Mahadevan, Sridhar; Dyar, M Darby

2017-07-01

The task of proper baseline or continuum removal is common to nearly all types of spectroscopy. Its goal is to remove any portion of a signal that is irrelevant to features of interest while preserving any predictive information. Despite the importance of baseline removal, median or guessed default parameters are commonly employed, often using commercially available software supplied with instruments. Several published baseline removal algorithms have been shown to be useful for particular spectroscopic applications but their generalizability is ambiguous. The new Custom Baseline Removal (Custom BLR) method presented here generalizes the problem of baseline removal by combining operations from previously proposed methods to synthesize new correction algorithms. It creates novel methods for each technique, application, and training set, discovering new algorithms that maximize the predictive accuracy of the resulting spectroscopic models. In most cases, these learned methods either match or improve on the performance of the best alternative. Examples of these advantages are shown for three different scenarios: quantification of components in near-infrared spectra of corn and laser-induced breakdown spectroscopy data of rocks, and classification/matching of minerals using Raman spectroscopy. Software to implement this optimization is available from the authors. By removing subjectivity from this commonly encountered task, Custom BLR is a significant step toward completely automatic and general baseline removal in spectroscopic and other applications.

Synthesis, spectral and thermal studies of pyridyl adducts of Zn(II) and Cd(II) dithiocarbamates, and their use as single source precursors for ZnS and CdS nanoparticles

OpenAIRE

Onwudiwe, Damian C.; Strydom, Christien A.; Jordaan, Anine; Oluwafemi, Oluwatobi S.; Hosten, Eric

2014-01-01

The synthesis, spectroscopic characterisation, and thermal studies of pyridyl adducts of Zn(II) and Cd(II) complexes of N-ethyl-N-phenyl dithiocarbamate, represented as [ZnL2py] and [CdL2py2], are reported. Single-crystal X-ray structural analysis of the Zn compound showed that it is five-coordinate with four sulphurs from dithiocarbamate and one nitrogen from pyridine in a distorted square pyramidal geometry. The thermogravimetric studies indicate that the zinc and cadmium compou...

Combining sequence-based prediction methods and circular dichroism and infrared spectroscopic data to improve protein secondary structure determinations

Directory of Open Access Journals (Sweden)

Lees Jonathan G

2008-01-01

Full Text Available Abstract Background A number of sequence-based methods exist for protein secondary structure prediction. Protein secondary structures can also be determined experimentally from circular dichroism, and infrared spectroscopic data using empirical analysis methods. It has been proposed that comparable accuracy can be obtained from sequence-based predictions as from these biophysical measurements. Here we have examined the secondary structure determination accuracies of sequence prediction methods with the empirically determined values from the spectroscopic data on datasets of proteins for which both crystal structures and spectroscopic data are available. Results In this study we show that the sequence prediction methods have accuracies nearly comparable to those of spectroscopic methods. However, we also demonstrate that combining the spectroscopic and sequences techniques produces significant overall improvements in secondary structure determinations. In addition, combining the extra information content available from synchrotron radiation circular dichroism data with sequence methods also shows improvements. Conclusion Combining sequence prediction with experimentally determined spectroscopic methods for protein secondary structure content significantly enhances the accuracy of the overall results obtained.

Synthesis, spectroscopic investigations, DFT studies, molecular docking and antimicrobial potential of certain new indole-isatin molecular hybrids: Experimental and theoretical approaches

Science.gov (United States)

Almutairi, Maha S.; Zakaria, Azza S.; Ignasius, P. Primsa; Al-Wabli, Reem I.; Joe, Isaac Hubert; Attia, Mohamed I.

2018-02-01

Indole-isatin molecular hybrids 5a-i have been synthesized and characterized by different spectroscopic methods to be evaluated as new antimicrobial agents against a panel of Gram positive bacteria, Gram negative bacteria, and moulds. Compound 5h was selected as a representative example of the prepared compounds 5a-i to perform computational investigations. Its vibrational properties have been studied using FT-IR and FT-Raman with the aid of density functional theory approach. The natural bond orbital analysis as well as HOMO and LUMO molecular orbitals investigations of compound 5h were carried out to explore its possible intermolecular delocalization or hyperconjugation and its possible interactions with the target protein. Molecular docking of compound 5h predicted its binding mode with the fungal target protein.

THE BARYON OSCILLATION SPECTROSCOPIC SURVEY OF SDSS-III

Energy Technology Data Exchange (ETDEWEB)

Dawson, Kyle S.; Ahn, Christopher P.; Bolton, Adam S. [Department of Physics and Astronomy, University of Utah, Salt Lake City, UT 84112 (United States); Schlegel, David J.; Bailey, Stephen [Lawrence Berkeley National Laboratory, One Cyclotron Road, Berkeley, CA 94720 (United States); Anderson, Scott F.; Bhardwaj, Vaishali [Department of Astronomy, University of Washington, Box 351580, Seattle, WA 98195 (United States); Aubourg, Eric; Bautista, Julian E. [APC, University of Paris Diderot, CNRS/IN2P3, CEA/IRFU, Observatoire de Paris, Sorbonne Paris Cite (France); Barkhouser, Robert H. [Department of Physics and Astronomy, Johns Hopkins University, Baltimore, MD 21218 (United States); Beifiori, Alessandra [Max-Planck-Institut fuer Extraterrestrische Physik, Giessenbachstrasse, D-85748 Garching (Germany); Berlind, Andreas A. [Department of Physics and Astronomy, Vanderbilt University, VU Station 1807, Nashville, TN 37235 (United States); Bizyaev, Dmitry; Brewington, Howard [Apache Point Observatory, P.O. Box 59, Sunspot, NM 88349 (United States); Blake, Cullen H. [Department of Astrophysical Sciences, Princeton University, Princeton, NJ 08544 (United States); Blanton, Michael R. [Center for Cosmology and Particle Physics, Department of Physics, New York University, 4 Washington Place, New York, NY 10003 (United States); Blomqvist, Michael [Department of Physics and Astronomy, University of California, Irvine, CA 92697 (United States); Borde, Arnaud [CEA, Centre de Saclay, Irfu/SPP, F-91191 Gif-sur-Yvette (France); Bovy, Jo [Institute for Advanced Study, Einstein Drive, Princeton, NJ 08540 (United States); Brandt, W. N., E-mail: kdawson@astro.utah.edu [Department of Astronomy and Astrophysics, 525 Davey Laboratory, The Pennsylvania State University, University Park, PA 16802 (United States); and others

2013-01-01

The Baryon Oscillation Spectroscopic Survey (BOSS) is designed to measure the scale of baryon acoustic oscillations (BAO) in the clustering of matter over a larger volume than the combined efforts of all previous spectroscopic surveys of large-scale structure. BOSS uses 1.5 million luminous galaxies as faint as i = 19.9 over 10,000 deg{sup 2} to measure BAO to redshifts z < 0.7. Observations of neutral hydrogen in the Ly{alpha} forest in more than 150,000 quasar spectra (g < 22) will constrain BAO over the redshift range 2.15 < z < 3.5. Early results from BOSS include the first detection of the large-scale three-dimensional clustering of the Ly{alpha} forest and a strong detection from the Data Release 9 data set of the BAO in the clustering of massive galaxies at an effective redshift z = 0.57. We project that BOSS will yield measurements of the angular diameter distance d{sub A} to an accuracy of 1.0% at redshifts z = 0.3 and z = 0.57 and measurements of H(z) to 1.8% and 1.7% at the same redshifts. Forecasts for Ly{alpha} forest constraints predict a measurement of an overall dilation factor that scales the highly degenerate D{sub A} (z) and H {sup -1}(z) parameters to an accuracy of 1.9% at z {approx} 2.5 when the survey is complete. Here, we provide an overview of the selection of spectroscopic targets, planning of observations, and analysis of data and data quality of BOSS.

Synthesis and spectroscopic and structural characterization of the monomeric diborylphosphine and diphosphinoborane compounds PhP(BMes2)2 and MesB(PPh2)2 (Mes = 2,4,6-Me3C6H2)

International Nuclear Information System (INIS)

Bartlett, R.A.; Dias, H.V.R.; Power, P.P.

1988-01-01

The synthesis and spectroscopic and first x-ray structural characterization of a diborylphosphine, PhP(BMes 2 ) 2 (1), and a diphosphinoborane, MesB(PPh 2 ) 2 (2), are described. The structure of 1 has a planar core that involves the phosphorus and two boron atoms and also the five substituent carbons. In addition, the B-P bond lengths are shortened, which suggests a close structural analogy between 1 and the allyl cation. In the case of 2, although the boron remains planar, both phosphorus centers are pyramidal with slightly longer B-P bonds than in 1. Both 1 and 2 are the first examples of their respective classes of compound to be well characterized. Crystal data with Mo Kα radiation (λ = 0.71069 /angstrom/) at 130 K are as follows. 1: a = 14.302 (4) /angstrom/, b = 15.701 (3) /angstrom/, c = 16.601 (6) /angstrom/, β = 109.61 (2)/degrees/; monoclinic, space group C2/c, Z = 4, R = 0.059. 2: a = 7.815 (2) /angstrom/, b = 8.723 (2) /angstrom/, c = 40.147 (10) /angstrom/, β = 94.90 (2)/degrees/; monoclinic, space group P2 1 /n, Z = 4, R = 0.041. A listing of available 11 B and 31 P NMR data on compounds involving triply connected boron and phosphorus centers is also provided and discussed in the context of the data for 1 and 2. 25 references, 2 figures, 4 tables

Spectroscopic studies of copper doped alkaline earth lead zinc phosphate glasses

Energy Technology Data Exchange (ETDEWEB)

Sastry, S. Sreehari, E-mail: sreeharisastry@yahoo.com [Department of Physics, Acharya Nagarjuna University, Nagarjunanagar 522510 (India); Rao, B. Rupa Venkateswara [Department of Physics, Acharya Nagarjuna University, Nagarjunanagar 522510 (India); Department of Physics, V.R. Siddhartha Engineering College, Vijayawada 52007 (India)

2014-02-01

In this paper spectroscopic investigation of Cu{sup 2+} doped alkaline earth lead zinc phosphate glasses was done through the spectroscopic techniques like X-ray diffraction, Ultra Violet (UV) absorption Spectroscopy, Electron Paramagnetic Resonance (EPR – X band), Fourier Transform Infra Red (FTIR) and Raman Spectroscopy. Alkaline earth lead zinc phosphate glasses containing 0.1% copper oxide (CuO) were prepared by the melt quenching technique. Spectroscopic studies indicated that there is a greater possibility for the copper ions to exist in Cu{sup 2+} state in these glasses. The optical absorption spectra indicated that the absorption peak of Cu{sup 2+} is a function of composition. The maxima absorption peak was reported at 862 nm for strontium lead zinc phosphate glass. Bonding parameters were calculated for the optical and EPR data. All these spectral results indicated clearly that there are certain structural changes in the present glass system with different alkaline earth contents. The IR and Raman spectra noticed the breaking of the P–O–P bonds and creating more number of new P–O–Cu bonds.

Spectroscopic studies of copper doped alkaline earth lead zinc phosphate glasses

International Nuclear Information System (INIS)

Sastry, S. Sreehari; Rao, B. Rupa Venkateswara

2014-01-01

In this paper spectroscopic investigation of Cu 2+ doped alkaline earth lead zinc phosphate glasses was done through the spectroscopic techniques like X-ray diffraction, Ultra Violet (UV) absorption Spectroscopy, Electron Paramagnetic Resonance (EPR – X band), Fourier Transform Infra Red (FTIR) and Raman Spectroscopy. Alkaline earth lead zinc phosphate glasses containing 0.1% copper oxide (CuO) were prepared by the melt quenching technique. Spectroscopic studies indicated that there is a greater possibility for the copper ions to exist in Cu 2+ state in these glasses. The optical absorption spectra indicated that the absorption peak of Cu 2+ is a function of composition. The maxima absorption peak was reported at 862 nm for strontium lead zinc phosphate glass. Bonding parameters were calculated for the optical and EPR data. All these spectral results indicated clearly that there are certain structural changes in the present glass system with different alkaline earth contents. The IR and Raman spectra noticed the breaking of the P–O–P bonds and creating more number of new P–O–Cu bonds

Development of laser atomic spectroscopic technology

International Nuclear Information System (INIS)

Lee, Jong Min; Ohr, Young Gie; Cha, Hyung Ki

1990-06-01

Some preliminary results on the resonant ionization spectroscopy for Na and Pb atoms are presents both in theory and in experiment. A single color multiphoton ionization process is theoretically analysed in detail, for the resonant and non-resonant cases, and several parameters determining the overall ionization rate are summarized. In particular, the AC stark shift, the line width and the non-linear coefficient of ionization rate are recalculated using the perturbation theory in resolvent approach. On the other hand, the fundamental equipments for spectroscopic experiments have been designed and manufactured, which include a Nd:YAG laser, a GIM-type dye laser, a vacuum system ionization cells, a heat pipe oven, and an ion current measuring system. The characteristics of the above equipments have also been examined. Using the spectroscopic data available, several ionization schemes are considered and the relative merits for ionization have been discussed. Moreover, the effects due to the buffer gas pressure, laser intensity, vapor density and electrode voltage have been investigated in detail. The experiments will be extended to multi-color processes with several resonances, and the ultimate goal is to develop a ultrasensitive analytical method for pollutive heavy metal atoms using the resonant ionization spectroscopy. (author)

Infrared Spectroscopic Imaging: The Next Generation

Science.gov (United States)

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

Synthesis, structural analysis, Hirshfeld surface, spectroscopic characterization and, in vitro, antioxidant activity of a novel organic cyclohexaphosphate

Science.gov (United States)

Fezai, Ramzi; Mezni, Ali; Rzaigui, Mohamed

2018-02-01

The new hybrid [4-Cl-2-(CH3)C6H3NH3]6P6O18·2H2O was synthesized under normal conditions of temperature and pressure. Single crystal X-ray diffraction study was used to identify its structure. It revealed that this organic cyclohexaphosphate crystallized in the P 1 bar triclinic space group with a = 10.41 (10) Å b = 10.94 (7) Å, c = 15.45 (10) Å, α = 77.37 (8), β = 89.75 (8)°, γ = 61.69 (7)°, V = 1501 (2) Å3 and Z = 1. In the crystal framework, the assembling of the three dimensional (3D) structure is formed by intermolecular hydrogen bonds and Van Der Waals interactions. A spectroscopic characterization was carried out to elucidate the structure (UV-Vis, FTIR, 31P MAS-NMR and fluorescent properties). The thermal stability was studied by TG-DTA diagrams under argon atmosphere. Furthermore, 3-D Hirshfeld surfaces in combination with 2-D fingerprint plots were carried out. This compound was also evaluated for its antioxidant activity; four tests were done, in vitro, 1,1-diphenyl-2-picrylhydrazyl (DPPH•), hydroxyl scavenging ability (OH•), ferric reducing power (FRP) and ferrous ion chelating (FIC) ability, using ascorbic acid as a control.

Profisetinidins: the first synthesis of tetraflavenoids: bi- and triflavenoids with terminal diolfunction. Profisetinidiene: die eerste sintese van tetraflavanoiede: bi- en triflavanoiede met terminale diolfunksie

Energy Technology Data Exchange (ETDEWEB)

Young, D A

1984-01-01

Chemists in the flavenoid field rely heavily on spectroscopic methods for unravelling complex flavenoid structures. The most powerful of these techniques - ultrahigh resolution /sup 1/H and /sup 13/C nmr spectroscopy - have certain inherent shortcomings especially at the tetraflavenoid level, owing to the obnormal high temperature requirements (>200/sup 0/C) to induce rapid rotation around the various interflavenoidbands and consequently sharply defined spectra. This problems have stressed the need for synthetic access to oligomeric tannins. In this study the coupling sequence and the stereochemistry of tetraflavenoids is determined via synthesis.

The LAMOST Complete Spectroscopic Survey of Pointing Area (LaCoSSPAr) in the Southern Galactic Cap. I. The Spectroscopic Redshift Catalog

Science.gov (United States)

Yang, Ming; Wu, Hong; Yang, Fan; Lam, Man I.; Cao, Tian-Wen; Wu, Chao-Jian; Zhao, Pin-Song; Zhang, Tian-Meng; Zhou, Zhi-Min; Wu, Xue-Bing; Zhang, Yan-Xia; Shao, Zheng-Yi; Jing, Yi-Peng; Shen, Shi-Yin; Zhu, Yi-Nan; Du, Wei; Lei, Feng-Jie; He, Min; Jin, Jun-Jie; Shi, Jian-Rong; Zhang, Wei; Wang, Jian-Ling; Wu, Yu-Zhong; Zhang, Hao-Tong; Luo, A.-Li; Yuan, Hai-Long; Bai, Zhong-Rui; Kong, Xu; Gu, Qiu-Sheng; Zhou, Xu; Ma, Jun; Hu, Zou; Nie, Jun-Dan; Wang, Jia-Li; Zhang, Yong; Hou, Yong-Hui; Zhao, Yong-Heng

2018-01-01

We present a spectroscopic redshift catalog from the LAMOST Complete Spectroscopic Survey of Pointing Area (LaCoSSPAr) in the Southern Galactic Cap (SGC), which is designed to observe all sources (Galactic and extragalactic) by using repeating observations with a limiting magnitude of r=18.1 {mag} in two 20 {\\deg }2 fields. The project is mainly focusing on the completeness of LAMOST ExtraGAlactic Surveys (LEGAS) in the SGC, the deficiencies of source selection methods, and the basic performance parameters of the LAMOST telescope. In both fields, more than 95% of galaxies have been observed. A post-processing has been applied to the LAMOST 1D spectrum to remove the majority of remaining sky background residuals. More than 10,000 spectra have been visually inspected to measure the redshift by using combinations of different emission/absorption features with an uncertainty of {σ }z/(1+z)visual inspection. Our analysis also indicates that up to one-fourth of the input targets for a typical extragalactic spectroscopic survey might be unreliable. The multi-wavelength data analysis shows that the majority of mid-infrared-detected absorption (91.3%) and emission line galaxies (93.3%) can be well separated by an empirical criterion of W2-W3=2.4. Meanwhile, a fainter sequence paralleled to the main population of galaxies has been witnessed both in M r /W2-W3 and M */W2-W3 diagrams, which could be the population of luminous dwarf galaxies but contaminated by the edge-on/highly inclined galaxies (∼ 30 % ).

Spectroscopic Needs for Imaging Dark Energy Experiments

International Nuclear Information System (INIS)

Newman, Jeffrey A.; Abate, Alexandra; Abdalla, Filipe B.; Allam, Sahar; Allen, Steven W.; Ansari, Reza; Bailey, Stephen; Barkhouse, Wayne A.; Beers, Timothy C.; Blanton, Michael R.; Brodwin, Mark; Brownstein, Joel R.; Brunner, Robert J.; Carrasco-Kind, Matias; Cervantes-Cota, Jorge; Chisari, Nora Elisa; Colless, Matthew; Coupon, Jean; Cunha, Carlos E.; Frye, Brenda L.; Gawiser, Eric J.; Gehrels, Neil; Grady, Kevin; Hagen, Alex; Hall, Patrick B.; Hearin, Andrew P.; Hildebrandt, Hendrik; Hirata, Christopher M.; Ho, Shirley; Huterer, Dragan; Ivezic, Zeljko; Kneib, Jean-Paul; Kruk, Jeffrey W.; Lahav, Ofer; Mandelbaum, Rachel; Matthews, Daniel J.; Miquel, Ramon; Moniez, Marc; Moos, H. W.; Moustakas, John; Papovich, Casey; Peacock, John A.; Rhodes, Jason; Ricol, Jean-Stepane; Sadeh, Iftach; Schmidt, Samuel J.; Stern, Daniel K.; Tyson, J. Anthony; Von der Linden, Anja; Wechsler, Risa H.; Wood-Vasey, W. M.; Zentner, A.

2015-01-01

Ongoing and near-future imaging-based dark energy experiments are critically dependent upon photometric redshifts (a.k.a. photo-z's): i.e., estimates of the redshifts of objects based only on flux information obtained through broad filters. Higher-quality, lower-scatter photo-z's will result in smaller random errors on cosmological parameters; while systematic errors in photometric redshift estimates, if not constrained, may dominate all other uncertainties from these experiments. The desired optimization and calibration is dependent upon spectroscopic measurements for secure redshift information; this is the key application of galaxy spectroscopy for imaging-based dark energy experiments. Hence, to achieve their full potential, imaging-based experiments will require large sets of objects with spectroscopically-determined redshifts, for two purposes: Training: Objects with known redshift are needed to map out the relationship between object color and z (or, equivalently, to determine empirically-calibrated templates describing the rest-frame spectra of the full range of galaxies, which may be used to predict the color-z relation). The ultimate goal of training is to minimize each moment of the distribution of differences between photometric redshift estimates and the true redshifts of objects, making the relationship between them as tight as possible. The larger and more complete our ''training set'' of spectroscopic redshifts is, the smaller the RMS photo-z errors should be, increasing the constraining power of imaging experiments; Requirements: Spectroscopic redshift measurements for ∼30,000 objects over >∼15 widely-separated regions, each at least ∼20 arcmin in diameter, and reaching the faintest objects used in a given experiment, will likely be necessary if photometric redshifts are to be trained and calibrated with conventional techniques. Larger, more complete samples (i.e., with longer exposure times) can improve photo

Spectroscopic identification of rare earth elements in phosphate glass

Science.gov (United States)

Devangad, Praveen; Tamboli, Maktum; Muhammed Shameem, K. M.; Nayak, Rajesh; Patil, Ajeetkumar; Unnikrishnan, V. K.; Santhosh, C.; Kumar, G. A.

2018-01-01

In this work, rare earth-doped phosphate glasses were synthesized and characterized using three different spectroscopic techniques. The absorption spectra of the prepared praseodymium (Pr) and samarium (Sm) doped glasses, recorded by a UV-VIS-NIR spectrophotometer, show the characteristic absorption bands of these elements. To confirm this inference, laser-induced fluorescence spectra of Pr and Sm were obtained at a laser excitation of 442 nm. Their emission bands are reported here. The elemental analysis of these samples was carried out using a laser-induced breakdown spectroscopy (LIBS) system. Characteristic emission lines of Pr and Sm have been identified and reported by the recorded LIBS spectra of glass samples. Results prove that using these three complimentary spectroscopic techniques (absorption, fluorescence and LIBS), we can meaningfully characterize rare earth-doped glass samples.

Mossbauer spectroscopic studies in ferroboron

Science.gov (United States)

Yadav, Ravi Kumar; Govindaraj, R.; Amarendra, G.

2017-05-01

Mossbauer spectroscopic studies have been carried out in a detailed manner on ferroboron in order to understand the local structure and magnetic properties of the system. Evolution of the local structure and magnetic properties of the amorphous and crystalline phases and their thermal stability have been addressed in a detailed manner in this study. Role of bonding between Fe 4s and/or 4p electrons with valence electrons of boron (2s,2p) in influencing the stability and magnetic properties of Fe-B system is elucidated.

A spectroscopic study of absorption and emission features of interstellar dust components

International Nuclear Information System (INIS)

Zwet, G.P. van der.

1986-01-01

The spectroscopic properties of silicate interstellar dust grains are the subject of this thesis. The process of accretion and photolysis is simulated in the laboratory by condensing mixtures of gases onto a cold substrate (T ∼ 12 K) in a vacuum chamber and photolyzing these mixtures with a vacuum ultraviolet source. Alternatively, the gas mixtures may be passed through a microwave discharge first, before deposition. The spectroscopic properties of the ices are investigated using ultraviolet, visible and infrared spectroscopy. (Auth.)

Synthesis of Radiation Curable Palm Oil-Based Epoxy Acrylate: NMR and FTIR Spectroscopic Investigations.

Science.gov (United States)

Salih, Ashraf M; Ahmad, Mansor Bin; Ibrahim, Nor Azowa; Dahlan, Khairul Zaman Hj Mohd; Tajau, Rida; Mahmood, Mohd Hilmi; Yunus, Wan Md Zin Wan

2015-08-04

Over the past few decades, there has been an increasing demand for bio-based polymers and resins in industrial applications, due to their potential lower cost and environmental impact compared with petroleum-based counterparts. The present research concerns the synthesis of epoxidized palm oil acrylate (EPOLA) from an epoxidized palm oil product (EPOP) as environmentally friendly material. EPOP was acrylated by acrylic acid via a ring opening reaction. The kinetics of the acrylation reaction were monitored throughout the reaction course and the acid value of the reaction mixture reached 10 mg KOH/g after 16 h, indicating the consumption of the acrylic acid. The obtained epoxy acrylate was investigated intensively by means of FTIR and NMR spectroscopy, and the results revealed that the ring opening reaction was completed successfully with an acrylation yield about 82%. The UV free radical polymerization of EPOLA was carried out using two types of photoinitiators. The radiation curing behavior was determined by following the conversion of the acrylate groups. The cross-linking density and the hardness of the cured EPOLA films were measured to evaluate the effect of the photoinitiator on the solid film characteristics, besides, the thermal and mechanical properties were also evaluated.

Scalar and configuration traces of operators in large spectroscopic spaces

International Nuclear Information System (INIS)

Chang, B.D.; Wong, S.S.M.

1978-01-01

In statistical spectroscopic calculations, the primary input is the trace of products of powers of Hamiltonian and excitation operators. The lack of a systematic approach to trace evaluation has been in the past one of the major difficulties in the applications of statistical spectroscopic methods. A general method with a simple derivation is described here to evaluate the scalar and configuration traces for operators expressed either in the m-scheme or fully coupled JT scheme. It is shown to be an effective method by actually programming it on a computer. Implications on the future applications of statistical spectroscopy in the area of level density, strength function and perturbation theory are also briefly discussed. (Auth.)

Spectroscopic studies on surface reactions between minerals and reagents in flotation systems

International Nuclear Information System (INIS)

Giesekke, E.W.

1981-01-01

A study of the adsorbed species at the interface between the minerals and the aqueous solution is reported in the hope that it will contribute to a better understanding of selective mineral flotation by various reagents. The results of infrared spectroscopic studies are cited from the author's investigation on the fluorite-sodium oleate and fluorite-linoleate systems. Electron-spectroscopic techniques, e.g., electron spectroscopy for chemical analysis (ESCA) have also been useful in the identification of adsorbed species on mineral surfaces. Some experimental data from the literature are discussed. These studies have the disadvantage that they are not in situ investigations of the interface between the mineral and the aqueous solution. The potential use of other spectroscopic techniques are discussed, photo-acoustic, Raman, and electron-spin-resonance spectroscopy being considered as possible alternatives. It is suggested that the relatively small surface areas of minerals used in flotation (i.e. smaller than 2m 2 .g- 1 ) impose severe restrictions on the use of such techniques

Synthesis of trifluoromethyl-substituted pyrazolo[4,3-c]pyridines – sequential versus multicomponent reaction approach

Directory of Open Access Journals (Sweden)

Barbara Palka

2014-07-01

Full Text Available A straightforward synthesis of 6-substituted 1-phenyl-3-trifluoromethyl-1H-pyrazolo[4,3-c]pyridines and the corresponding 5-oxides is presented. Hence, microwave-assisted treatment of 5-chloro-1-phenyl-3-trifluoromethylpyrazole-4-carbaldehyde with various terminal alkynes in the presence of tert-butylamine under Sonogashira-type cross-coupling conditions affords the former title compounds in a one-pot multicomponent procedure. Oximes derived from (intermediate 5-alkynyl-1-phenyl-3-trifluoromethyl-1H-pyrazole-4-carbaldehydes were transformed into the corresponding 1H-pyrazolo[4,3-c]pyridine 5-oxides by silver triflate-catalyzed cyclization. Detailed NMR spectroscopic investigations (1H, 13C, 15N and 19F were undertaken with all obtained products.

New porphyrin-polyoxometalate hybrid materials: synthesis, characterization and investigation of catalytic activity in acetylation reactions.

Science.gov (United States)

Araghi, Mehdi; Mirkhani, Valiollah; Moghadam, Majid; Tangestaninejad, Shahram; Mohammdpoor-Baltork, Iraj

2012-10-14

New hybrid complexes based on covalent interaction between 5,10,15,20-tetrakis(4-aminophenyl)porphyrinatozinc(II) and 5,10,15,20-tetrakis(4-aminophenyl)porphyrinatotin(IV) chloride, and a Lindqvist-type polyoxometalate, Mo(6)O(19)(2-), were prepared. These new porphyrin-polyoxometalate hybrid materials were characterized by (1)H NMR, FT IR and UV-Vis spectroscopic methods and cyclic voltammetry. These spectro- and electrochemical studies provided several spectral data for synthesis of these compounds. Cyclic voltammetry showed the influence of the polyoxometalate on the redox process of the porphyrin ring. The catalytic activity of tin(IV)porphyrin-hexamolybdate hybrid material was investigated in the acetylation of alcohols and phenols with acetic anhydride. The reusability of this catalyst was also investigated.

Raman spectroscopic study of some chalcopyrite-xanthate flotation products

CSIR Research Space (South Africa)

Andreev, GN

2003-12-16

Full Text Available of normal vibrations of the corresponding individual compounds. The latter facilitated the Raman spectroscopic elucidation of the reaction products formed on the chalcopyrite surface in real industrial flotation conditions with a sodium isopropyl xanthate...

A Speckle survey of Southern Hipparcos Visual Doubles and Geneva-Copenhagen Spectroscopic Binaries

Science.gov (United States)

Mendez, R. A.; Tokovinin, A.; Horch, E.

2018-01-01

We present a speckle survey of Hipparcos visual doubles and spectroscopic binary stars identified by the Geneva-Copenhagen spectroscopic survey with the SOAR 4m telescope + HRCam. These systems represent our best chance to take advantage of Gaia parallaxes for the purpose of stellar mass determinations. Many of these systems already have mass fractions (although generally no spectroscopic orbit - an astrometric orbit will determine individual masses), metallicity information, and Hipparcos distances. They will be used to improve our knowledge of the mass-luminosity relation, particularly for lower-metallicity stars. Our survey will create the first all-sky, volume-limited, speckle archive for the two primary samples, complementing a similar effort that has been recently been completed at the WIYN 3.5-m telescope in the Northern Hemisphere. This extension to the Southern Hemisphere will fill out the picture for a wider metallicity range.

Radiation induced synthesis of conducting polymers and their metal nano-composites

International Nuclear Information System (INIS)

Cui, Zhenpeng

2017-01-01

The aim of the present work is to demonstrate the versatility of the gamma (γ)-rays based radiolytic method and to extend our methodology to the synthesis of various conducting polymers (CPs) in water in different experimental conditions. Poly(3,4-ethylenedioxy-thiophene) (PEDOT) and poly-pyrrole (PPy) conjugated polymers were successfully prepared and characterized in solution and after deposition by complementary spectroscopic and microscopic techniques. Also their thermal stability and their electrical conductivity were studied and compared with those of CPs prepared by conventional methods. The influence of the nature of radiation-induced oxidizing radicals, of the ionic strength, of the medium, of the pH, of the presence of surfactant-based soft templates on the growth mechanism, on the efficiency of polymerization, on the morphology of the obtained CPs as well as on their absorption and conducting properties was checked. Also, the radiolytic method was extend to the synthesis of CPs/noble metal nano-composites. Different preparation methodologies were developed based on two-step method and one-pot method, by using oxidation route or reduction route. Our new radiolytic strategy described and extended in this manuscript opens the way for the preparation of different kinds of CPs and CPs nano-composites not only in aqueous solutions but also in various environments foreshadowing many promising applications.. (author)

Spectroscopic and antimicrobial studies of polystyrene films under ...

Indian Academy of Sciences (India)

Spectroscopic and antimicrobial studies of polystyrene films under air plasma and He-Ne laser treatment ... The parameters such as (1) surface area by contact angle measurements, (2) quality of material before and after treatment by SEM and FTIR spectra and (3) material characterization by UV-vis spectra were studied.

Cadmium (II) macrocyclic Schiff-base complexes containing piperazine moiety: Synthesis, spectroscopic, X-ray structure, theoretical and antibacterial studies

Science.gov (United States)

Keypour, Hassan; Mahmoudabadi, Masoumeh; Shooshtari, Amir; Bayat, Mehdi; Mohsenzadeh, Fariba; Gable, Robert William

2018-03-01

The new Cd(II) macrocyclic Schiff-base complexes were prepared via the metal templated [1 + 1] cyclocondensation of 2,2'-(piperazine-1,4-diylbis (methylene))dianiline (A) and 2,6-pyridinedicarbaldehyde or 2,6-diacetylpyridine. The products were characterized by elemental analysis, mass spectrometry and spectroscopic methods such as: FT-IR, 1H and 13C-NMR, the crystal structure of [CdL1(ClO4)2](CH3CN) (1) complex was also obtained by single-crystal X-ray crystallography. The complexes were tested for in vitro antibacterial properties against some bacteria. The complexes had antibacterial properties and in some cases were active even more than standards. The geometries of the [CdLn (ClO4)2], (n = 1,2) complexes have been optimized at the BP86/def2-SVP level of theory. Also the nature of Cd←Ln (n = 1, 2) bonds in [CdLn (ClO4)2], (n = 1,2) complexes are studied with the help of NBO and Energy decomposition analysis (EDA). Results showed that the nature of metal-ligand bond in the complexes is slightly more electrostatic with a contribution of about 52% in total interaction energy.

Synthesis, spectroscopic, structural and optical studies of Ru2S3 nanoparticles prepared from single-source molecular precursors

Science.gov (United States)

Mbese, Johannes Z.; Ajibade, Peter A.

2017-09-01

Homonuclear tris-dithiocarbamato ruthenium(III) complexes, [Ru(S2CNR2)3] were prepared and characterized by spectroscopic techniques and thermogravimetric analyses. The thermogravimetric analyses (TGA) of the ruthenium complexes showed that the complexes decompose to ruthenium(III) sulfide nanoparticles. The ruthenium(III) complexes were dispersed in oleic acid and thermolysed in hexadecylamine to prepared oleic acid/hexadecylamine capped Ru2S3 nanoparticles. FTIR revealed that Ru2S3 nanoparticles are capped through the interaction of the -NH2 group of hexadecylamine HDA adsorbed on the surfaces of nanoparticles and it also showed that oleic acid (OA) is acting as both coordinating stabilizing surfactant and capping agent. EDS spectra revealed that the prepared nanoparticles are mainly composed of Ru and S, confirming the formation of Ru2S3 nanoparticles. Powder XRD confirms that the nanoparticles are in cubic phase. The inner morphology of nanoparticles obtained from transmission electron microscopy (TEM) showed nanoparticles with narrow particle size distributions characterized by an average diameter of 8.45 nm with a standard deviation of 1.6 nm. The optical band gap (Eg) determined from Tauc plot are in the range 3.44-4.18 eV.

Study of mechanism of enhanced antibacterial activity by green synthesis of silver nanoparticles

Science.gov (United States)

Parashar, Upendra Kumar; Kumar, Vinod; Bera, Tanmay; Saxena, Preeti S.; Nath, Gopal; Srivastava, Sunil K.; Giri, Rajiv; Srivastava, Anchal

2011-10-01

The extensive use of silver nanoparticles needs a synthesis process that is greener without compromising their properties. The present study describes a novel green synthesis of silver nanoparticles using Guava (Psidium guajava) leaf extract. In order to compare with the conventionally synthesized ones, we also prepared Ag-NPs by chemical reduction. Their optical and morphological characteristics were thoroughly investigated and tested for their antibacterial properties on Escherichia coli. The green synthesized silver nanoparticles showed better antibacterial properties than their chemical counterparts even though there was not much difference between their morphologies. Fourier transform infrared (FTIR) spectroscopic analysis of the used extract and as-synthesized silver nanoparticles suggests the possible reduction of Ag + by the water-soluble ingredients of the guava leaf like tannins, eugenol and flavonoids. The possible reaction mechanism for the reduction of Ag + has been proposed and discussed. The time-dependent electron micrographs and the simulation studies indicated that a physical interaction between the silver nanoparticles and the bacterial cell membrane may be responsible for this effect. Based on the findings, it seems very reasonable to believe that this greener way of synthesizing silver nanoparticles is not just an environmentally viable technique but it also opens up scope to improve their antibacterial properties.

Study of mechanism of enhanced antibacterial activity by green synthesis of silver nanoparticles

Energy Technology Data Exchange (ETDEWEB)

Parashar, Upendra Kumar; Srivastava, Sunil K; Srivastava, Anchal [Department of Physics, Banaras Hindu University, Varanasi 221005 (India); Kumar, Vinod; Saxena, Preeti S [Department of Zoology, Banaras Hindu University, Varanasi 22005 (India); Bera, Tanmay [Department of Mechanical, Materials and Aerospace Engineering, University of Central Florida, Orlando, FL 32816 (United States); Nath, Gopal [Department of Microbiology, Institute of Medical Science, Banaras Hindu University, Varanasi 22005 (India); Giri, Rajiv, E-mail: anchalbhu@gmail.com [Department of Materials Science and Engineering, Norwegian University of Science and Technology, NO-7491 Trondheim (Norway)

2011-10-14

The extensive use of silver nanoparticles needs a synthesis process that is greener without compromising their properties. The present study describes a novel green synthesis of silver nanoparticles using Guava (Psidium guajava) leaf extract. In order to compare with the conventionally synthesized ones, we also prepared Ag-NPs by chemical reduction. Their optical and morphological characteristics were thoroughly investigated and tested for their antibacterial properties on Escherichia coli. The green synthesized silver nanoparticles showed better antibacterial properties than their chemical counterparts even though there was not much difference between their morphologies. Fourier transform infrared (FTIR) spectroscopic analysis of the used extract and as-synthesized silver nanoparticles suggests the possible reduction of Ag{sup +} by the water-soluble ingredients of the guava leaf like tannins, eugenol and flavonoids. The possible reaction mechanism for the reduction of Ag{sup +} has been proposed and discussed. The time-dependent electron micrographs and the simulation studies indicated that a physical interaction between the silver nanoparticles and the bacterial cell membrane may be responsible for this effect. Based on the findings, it seems very reasonable to believe that this greener way of synthesizing silver nanoparticles is not just an environmentally viable technique but it also opens up scope to improve their antibacterial properties.

THE SDSS-IV EXTENDED BARYON OSCILLATION SPECTROSCOPIC SURVEY: OVERVIEW AND EARLY DATA

Energy Technology Data Exchange (ETDEWEB)

Dawson, Kyle S.; Bautista, Julian E. [Department of Physics and Astronomy, University of Utah, Salt Lake City, UT 84112 (United States); Kneib, Jean-Paul [Laboratoire dástrophysique, Ecole Polytechnique Fédérale de Lausanne Observatoire de Sauverny, 1290 Versoix (Switzerland); Percival, Will J. [Institute of Cosmology and Gravitation, Dennis Sciama Building, University of Portsmouth, Portsmouth, PO1 3FX (United Kingdom); Alam, Shadab [Bruce and Astrid McWilliams Center for Cosmology, Department of Physics, Carnegie Mellon University, 5000 Forbes Ave, Pittsburgh, PA 15213 (United States); Albareti, Franco D. [Instituto de Física Teórica, (UAM/CSIC), Universidad Autónoma de Madrid, Cantoblanco, E-28049 Madrid (Spain); Anderson, Scott F. [Department of Astronomy, University of Washington, Box 351580, Seattle, WA 98195 (United States); Armengaud, Eric [CEA, Centre de Saclay, Irfu/SPP, F-91191 Gif-sur-Yvette (France); Aubourg, Éric [APC, University of Paris Diderot, CNRS/IN2P3, CEA/IRFU, Observatoire de Paris, Sorbonne Paris Cite (France); Bailey, Stephen; Beutler, Florian [Lawrence Berkeley National Laboratory, One Cyclotron Road, Berkeley, CA 94720 (United States); Berlind, Andreas A. [Department of Physics and Astronomy, Vanderbilt University, PMB 401807, 2401 Vanderbilt Place, Nashville, TN 37240 (United States); Bershady, Matthew A. [University of Wisconsin-Madison, Department of Astronomy, 475 N. Charter St., Madison WI 53703 (United States); Bizyaev, Dmitry [Apache Point Observatory, P.O. Box 59, sunspot, NM 88349 (United States); Blanton, Michael R., E-mail: kdawson@astro.utah.edu [Center for Cosmology and Particle Physics, Department of Physics, New York University, 4 Washington Place, New York, NY 10003 (United States); and others

2016-02-15

In a six-year program started in 2014 July, the Extended Baryon Oscillation Spectroscopic Survey (eBOSS) will conduct novel cosmological observations using the BOSS spectrograph at Apache Point Observatory. These observations will be conducted simultaneously with the Time Domain Spectroscopic Survey (TDSS) designed for variability studies and the Spectroscopic Identification of eROSITA Sources (SPIDERS) program designed for studies of X-ray sources. In particular, eBOSS will measure with percent-level precision the distance-redshift relation with baryon acoustic oscillations (BAO) in the clustering of matter. eBOSS will use four different tracers of the underlying matter density field to vastly expand the volume covered by BOSS and map the large-scale-structures over the relatively unconstrained redshift range 0.6 < z < 2.2. Using more than 250,000 new, spectroscopically confirmed luminous red galaxies at a median redshift z = 0.72, we project that eBOSS will yield measurements of the angular diameter distance d{sub A}(z) to an accuracy of 1.2% and measurements of H(z) to 2.1% when combined with the z > 0.6 sample of BOSS galaxies. With ∼195,000 new emission line galaxy redshifts, we expect BAO measurements of d{sub A}(z) to an accuracy of 3.1% and H(z) to 4.7% at an effective redshift of z = 0.87. A sample of more than 500,000 spectroscopically confirmed quasars will provide the first BAO distance measurements over the redshift range 0.9 < z < 2.2, with expected precision of 2.8% and 4.2% on d{sub A}(z) and H(z), respectively. Finally, with 60,000 new quasars and re-observation of 60,000 BOSS quasars, we will obtain new Lyα forest measurements at redshifts z > 2.1; these new data will enhance the precision of d{sub A}(z) and H(z) at z > 2.1 by a factor of 1.44 relative to BOSS. Furthermore, eBOSS will provide improved tests of General Relativity on cosmological scales through redshift-space distortion measurements, improved tests for non

Molecular design, synthesis and physical properties of novel Cytisine-derivatives - Experimental and theoretical study

Science.gov (United States)

Ivanova, Bojidarka; Spiteller, Michael

2013-02-01

The paper presented a comprehensive theoretical and experimental study on the molecular drugs-design, synthesis, isolation, physical spectroscopic and mass spectrometric elucidation of novel functionalization derivatives of Cytisine (Cyt), using nucleosidic residues. Since these alkaloids have established biochemical profile, related the binding affinity of the nicotinic acetylcholine receptors (nAChRs), particularly α7 sub-type, the presented correlation between the molecular structure and properties allowed to evaluated the highlights of the biochemical hypothesises related the Schizophrenia. The anticancer activity of α7 subtype agonists and the crucial role of the nucleoside-based medications in the cancer therapy provided opportunity for further study on the biochemical relationship between Schizophrenia and few kinds of cancers, which has been hypothesized recently. The physical electronic absorptions (EAs), circular dichroic (CD) and Raman spectroscopic (RS) properties as well as mass spectrometric (MS) data, obtained using electrospray ionization (ESI) and atmospheric-pressure chemical ionization (APCI) methods under the positive single (MS) and tandem (MS/MS) modes of operation are discussed. Taking into account reports on a fatal intoxication of Cyt, the presented data would be of interest in the field of forensic chemistry, through development of highly selective and sensitive analytical protocols. Quantum chemical method is used to predict the physical properties of the isolated alkaloids, their affinity to the receptor loop and gas-phase stabilized species, observed mass spectrometrically.

Gas Chromatography-Mass Spectroscopic (GC-MS) Analysis of n ...

African Journals Online (AJOL)

1Department of Pharmacognosy and Phytotherapy, 2Department of Pharmaceutics and Pharmaceutical Technology, University of Port Harcourt, Nigeria ... tuber-regium (synonym Pleurotus tuber regium) using gas chromatography-mass spectroscopic (GC- ... Department of Plant Science and Biotechnology,. University of ...

ITER perspective on fusion reactor diagnostics - A spectroscopic view

DEFF Research Database (Denmark)

De Bock, M. F. M.; Barnsley, R.; Bassan, M.

2016-01-01

challenges to the development of spectroscopic (but also other) diagnostics. This contribution presents an overview of recent achievements in 4 topical areas: First mirror protection and cleaning, Nuclear confinement, Radiation mitigation strategy for optical and electronic components and Calibration...

Particle in a Disk: A Spectroscopic and Computational Laboratory Exercise Studying the Polycyclic Aromatic Hydrocarbon Corannulene

Science.gov (United States)

Frey, E. Ramsey; Sygula, Andrzej; Hammer, Nathan I.

2014-01-01

This laboratory exercise introduces undergraduate chemistry majors to the spectroscopic and theoretical study of the polycyclic aromatic hydrocarbon (PAH), corannulene. Students explore the spectroscopic properties of corannulene using UV-vis and Raman vibrational spectroscopies. They compare their experimental results to simulated vibrational…

Electrochemical and spectroscopic characterisation of amphetamine-like drugs: Application to the screening of 3,4-methylenedioxymethamphetamine (MDMA) and its synthetic precursors

International Nuclear Information System (INIS)

Milhazes, Nuno; Martins, Pedro; Uriarte, Eugenio; Garrido, Jorge; Calheiros, Rita; Marques, M. Paula M.; Borges, Fernanda

2007-01-01

A complete physicochemical characterisation of MDMA and its synthetic precursors MDA, 3,4-methylenedioxybenzaldehyde (piperonal) and 3,4-methylenedioxy-β-methyl-β-nitrostyrene was carried out through voltammetric assays and Raman spectroscopy combined with theoretical (DFT) calculations. The former provided important analytical redox data, concluding that the oxidative mechanism of the N-demethylation of MDMA involves the removal of an electron from the amino-nitrogen atom, leading to the formation of a primary amine and an aldehyde. The vibrational spectroscopic experiments enable to afford a rapid and reliable detection of this type of compounds, since they yield characteristic spectral patterns that lead to an unequivocal identification. Moreover, the rational synthesis of the drug of abuse 3,4-methylenedioxymethamphetamine (MDMA or 'ecstasy') from one of its most relevant precursors 3,4-methylene-dioxyamphetamine (MDA), is reported. In addition, several approaches for the N-methylation of MDA, a limiting synthetic step, were attempted and the overall yields compared

Electrochemical and spectroscopic characterisation of amphetamine-like drugs: Application to the screening of 3,4-methylenedioxymethamphetamine (MDMA) and its synthetic precursors

Energy Technology Data Exchange (ETDEWEB)

Milhazes, Nuno [CEQOFFUP, Faculdade de Farmacia, Universidade do Porto (Portugal); Departamento de Quimica Organica, Faculdade de Farmacia, Universidade do Porto (Portugal); Instituto Superior de Ciencias da Saude-Norte, Gandra, Paredes (Portugal); Martins, Pedro [Departamento de Quimica Organica, Facultade de Farmacia, Universidad de Santiago de Compostela (Spain); Uriarte, Eugenio [Departamento de Quimica Organica, Facultade de Farmacia, Universidad de Santiago de Compostela (Spain); Garrido, Jorge [Unidade I and D ' Quimica-Fisica Molecular' (Portugal); Departamento de Engenharia Quimica, ISEP, Instituto Politecnico do Porto (Portugal); Calheiros, Rita [Unidade I and D ' Quimica-Fisica Molecular' (Portugal); Marques, M. Paula M. [Unidade I and D ' Quimica-Fisica Molecular' (Portugal); Departamento de Bioquimica, Faculdade de Ciencias e Tecnologia, Universidade de Coimbra (Portugal); Borges, Fernanda [Departamento de Quimica Organica, Faculdade de Farmacia, Universidade do Porto (Portugal) and Unidade I and D ' Quimica-Fisica Molecular' (Portugal)]. E-mail: fborges@ff.up.pt

2007-07-23

A complete physicochemical characterisation of MDMA and its synthetic precursors MDA, 3,4-methylenedioxybenzaldehyde (piperonal) and 3,4-methylenedioxy-{beta}-methyl-{beta}-nitrostyrene was carried out through voltammetric assays and Raman spectroscopy combined with theoretical (DFT) calculations. The former provided important analytical redox data, concluding that the oxidative mechanism of the N-demethylation of MDMA involves the removal of an electron from the amino-nitrogen atom, leading to the formation of a primary amine and an aldehyde. The vibrational spectroscopic experiments enable to afford a rapid and reliable detection of this type of compounds, since they yield characteristic spectral patterns that lead to an unequivocal identification. Moreover, the rational synthesis of the drug of abuse 3,4-methylenedioxymethamphetamine (MDMA or 'ecstasy') from one of its most relevant precursors 3,4-methylene-dioxyamphetamine (MDA), is reported. In addition, several approaches for the N-methylation of MDA, a limiting synthetic step, were attempted and the overall yields compared.

Electrochemical and spectroscopic characterisation of amphetamine-like drugs: application to the screening of 3,4-methylenedioxymethamphetamine (MDMA) and its synthetic precursors.

Science.gov (United States)

Milhazes, Nuno; Martins, Pedro; Uriarte, Eugenio; Garrido, Jorge; Calheiros, Rita; Marques, M Paula M; Borges, Fernanda

2007-07-23

A complete physicochemical characterisation of MDMA and its synthetic precursors MDA, 3,4-methylenedioxybenzaldehyde (piperonal) and 3,4-methylenedioxy-beta-methyl-beta-nitrostyrene was carried out through voltammetric assays and Raman spectroscopy combined with theoretical (DFT) calculations. The former provided important analytical redox data, concluding that the oxidative mechanism of the N-demethylation of MDMA involves the removal of an electron from the amino-nitrogen atom, leading to the formation of a primary amine and an aldehyde. The vibrational spectroscopic experiments enable to afford a rapid and reliable detection of this type of compounds, since they yield characteristic spectral patterns that lead to an unequivocal identification. Moreover, the rational synthesis of the drug of abuse 3,4-methylenedioxymethamphetamine (MDMA or "ecstasy") from one of its most relevant precursors 3,4-methylene-dioxyamphetamine (MDA), is reported. In addition, several approaches for the N-methylation of MDA, a limiting synthetic step, were attempted and the overall yields compared.

Features of the use of charge-coupled devices in emission spectroscopic analysis

International Nuclear Information System (INIS)

Livshits, A.M.; Peleznev, A.V.

1993-01-01

Multielement radiation receivers based on linear charge-coupled photodiode devices have become more aand more widely used recently in spectroscopic analysis. The main feature of such receivers is their ability to record not only the intensity of the incident light flux, but also its spatial distribution. This article considers the advantages and disadvantages of charge-coupled devices when used in emission spectroscopic analysis. The main methods nd devices employed for this purpose and discussed here can be divided into four types: photographic photometry, visual styloscopy, quantometry, and successive analysis. 4 refs., 1 fig

Immunocytochemistry by electron spectroscopic imaging using a homogeneously boronated peptide.

Science.gov (United States)

Kessels, M M; Qualmann, B; Klobasa, F; Sierralta, W D

1996-05-01

A linear all-L-oligopeptide containing five carboranyl amino acids (corresponding to 50 boron atoms) was synthesized and specifically attached to the free thiol group of monovalent antibody fragments F(ab)'. The boronated immunoreagent was used for the direct post-embedding detection of somatotrophic hormone in ultrathin sections of porcine pituitary embedded in Spurr resin. The specific boron-labelling of secretory vesicles in somatotrophs was detected by electron spectroscopic imaging and confirmed by conventional immunogold labelling run in parallel. In comparison with immunogold, boron-labelled F(ab)'-fragments showed higher tagging frequencies, as was expected; the small uncharged immunoreagents have an elongated shape and carry the antigen-combining structure and the detection tag at opposite ends, thus allowing for high spatial resolution in electron spectroscopic imaging.

Synthesis of 13C and 2H labelled retinals: spectroscopic investigations on isotopically labelled rhodopsin and bacteriorhodopsin

International Nuclear Information System (INIS)

Pardoen, J.A.

1986-01-01

In order to develop probes of the structure of chromophores, the author introduces isotopic modifications at specific chromophoric positions as structural probes. To obtain bacteriorhodopsin, rhodopsin and their photoproducts labelled in the chromophore at selected positions, bacterioopsin and opsin were reacted with the appropriate labelled a11-trans and 11-cis retinals. The author describes the synthesis of a11-trans retinal selectively 13 C labelled at different positions. The characterization of these labelled a11-trans retinals by mass spectrometry, 300 MHz 1 H NMR and 75 MHz 13 C NMR spectroscopy is given. The photochemical preparation and isolation of the pure 9-, 11- and 13-cis forms is described in the experimental part. (Auth.)

Design, Synthesis, Structural and Spectroscopic Studies of Push-Pull Two-Photon Absorbing Chromophores with Acceptor Groups of Varying Strength

Science.gov (United States)

Morales, Alma R.; Frazer, Andrew; Woodward, Adam W.; Ahn-White, Hyo-Yang; Fonari, Alexandr; Tongwa, Paul; Timofeeva, Tatiana; Belfield, Kevin D.

2013-01-01

A new series of unsymmetrical diphenylaminofluorene-based chromophores with various strong π-electron acceptors were synthesized and fully characterized. The systematic alteration of the structural design facilitated the investigation of effects such as molecular symmetry and strength of electron-donating and/or withdrawing termini have on optical nonlinearity. In order to determine the electronic and geometrical properties of the novel compounds, a thorough investigation was carried out by a combination of linear and nonlinear spectroscopic techniques, single crystal X-ray diffraction, and quantum chemical calculations. Finally, on the basis of two-photon absorption (2PA) cross sections, the general trend for π -electron accepting ability, i.e., ability to accept charge transfer from diphenylamine was: 2-pyran-4-ylidene malononitrile (pyranone) > dicyanovinyl > bis(dicyanomethylidene)indane > 1-(thiophen-2-yl)propenone > dicyanoethylenyl > 3-(thiophen-2-yl)propenone. An analog with the 2-pyran-4-ylidene malononitrile acceptor group exhibited a nearly three-fold enhancement of the 2PA< δ (1650 GM at 840 nm), relative to other members of the series. PMID:23305555

Plant-mediated green synthesis of ZnO nanoparticles using Garcinia gummi-gutta seed extract: Photoluminescence, screening of their catalytic activity in antioxidant, formylation and biodiesel production

Science.gov (United States)

Raghavendra, M.; Yatish, K. V.; Lalithamba, H. S.

2017-08-01

The green synthesis of multifunctional ZnO nanoparticles (NPs) was prepared by treatment of zinc nitrate with an extract of Garcinia gummi-gutta seed by the combustion method. The ZnO NPs were characterized by XRD, scanning electron microscopy, UV-visible, FTIR spectroscopic techniques. The prepared ZnO NPs were evaluated for photoluminescence (PL), antioxidant properties and also utilized as a catalyst for the formylation of aromatic amines and biodiesel production. The study reveals that the reaction is simple, mild and environmental friendly. Furthermore, the reaction results in excellent yield of products.

Biogenic synthesis and spectroscopic characterization of silver nanoparticles using leaf extract of Indoneesiella echioides: in vitro assessment on antioxidant, antimicrobial and cytotoxicity potential

Science.gov (United States)

Kuppurangan, Gunaseelan; Karuppasamy, Balaji; Nagarajan, Kanipandian; Krishnasamy Sekar, Rajkumar; Viswaprakash, Nilmini; Ramasamy, Thirumurugan

2016-10-01

Natural synthesis of metal nanoparticles is gaining more attention in recent years. This article demonstrates the phytochemical synthesis of silver nanoparticles (AgNPs) by using Indoneesiella echioides (L) leaf extract as a reducing and stabilizing agent. Biosynthesis of AgNPs was monitored by UV-visible spectroscopy which revealed intense surface plasmon resonance bands at 420 nm. Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction were employed to identify various functional groups and crystalline nature of AgNPs. High-resolution transmission electron microscopy studies demonstrated that synthesized particles were spherical with average size of ~29 nm. In vitro antioxidant effects were analyzed by 2,2'-Azino-bis-(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS) and 2,2-diphenyl-1-picrylhydrazyl (DPPH), which exhibited 69 and 71 % of scavenging activity, respectively. The antimicrobial activity of green AgNPs displayed better zone of inhibition against selected human pathogens. The present study also investigated the toxicity effect of biogenic AgNPs against human lung adenocarcinoma cancer cells (A549) and normal human epithelial cells (HBL-100) in vitro, and the inhibitory concentrations (IC50) were found to be 30 and 60 µg/mL, respectively. Herein, we propose a previously unexplored medicinal plant for the biological synthesis of AgNPs with potent biomedical applications.

Chemical and spectroscopic characterization of a vegetable oil used as dielectric coolant in distribution transformers

Energy Technology Data Exchange (ETDEWEB)

Gomez, Neffer A.; Abonia, Rodrigo, E-mail: rodrigo.abonia@correounivalle.edu.co [Departamento de Quimica, Escuela de Ingenieria Electrica, Universidad del Valle, Cali (Colombia); Cadavid, Hector [Grupo GRALTA, Escuela de Ingenieria Electrica, Universidad del Valle, Cali (Colombia); Vargas, Ines H. [Area de Ingenieria de Distribucion, Empresas Publicas de Medellin (EPM), Medellin (Colombia)

2011-09-15

In this work, a complete UV-Vis, IR and (1H, 13C and DEPT) NMR spectroscopic analysis was performed for a FR3 vegetable oil sample used as dielectric coolant in an experimental distribution transformer. The same spectroscopic analysis was performed for three used FR3 oil samples (i.e., 4 months in use, 8 months in use and 7 years in use), removed from several operating distribution transformers. Comparison of the data indicated that no significant spectroscopic changes, and hence, no structural changes occurred to the oils by the use. Chemical transformations like catalytic hydrogenation (hardening) and hydrolysis were performed to the FR3 oil sample and the obtained products were analyzed by spectroscopic methods in order to collect further structural information about the FR3 oil. Accelerated aging tests in laboratory were also performed for three FR3 oil samples affording interesting information about the structure of the degradation products. These findings would be valuable to search for a spectroscopy-based technique for monitoring the lifetime and performance of this insulating vegetable oil. (author)

Electrochemical and spectroscopic studies of uranium(IV), -(V), and -(VI) in carbonate-bicarbonate buffers

International Nuclear Information System (INIS)

Wester, D.W.; Sullivan, J.C.

1980-01-01

Recently a need for more detailed knowledge of the chemistry of actinide ions in basic media has arisen in connection with deducing their chemistry in the environment. In this work the results of polarographic, cyclic voltammetric, and spectroscopic studies of U(IV), -(V), and -(VI) in carbonate and bicarbonate media are reported. Polarographic studies were in excellent agreement with those reported previously. Cyclic voltammetric scans confirmed the irreversible reduction to U(V) in both solutions, but disproportionation of the U(V) was observed only in the bicarbonate solutions. The oxidation of U(V) in carbonate was followed spectroscopically for the first time. Reduction in bicarbonate produced U(IV), the spectrum of which is now reported and the oxidation of which was also followed spectroscopically for the first time

Syntheses and spectroscopic properties of mercury(II) and nickel(II ...

African Journals Online (AJOL)

Syntheses and spectroscopic properties of mercury(II) and nickel(II) ... The complexes were characterized by IR, diffuse reflectance, 1H NMR spectra and elemental ... coordinating through thiolato sulphur and hydrazinic nitrogen atoms.

A spectroscopic transfer standard for accurate atmospheric CO measurements

Science.gov (United States)

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

Cytotoxicity and utility of 1-indanone in the synthesis of some new heterocycles.

Science.gov (United States)

Hegazi, Bahira; Mohamed, Hanan Ahmed; Dawood, Kamal Mohamed; Badria, Farid Abdel-Rahem

2010-04-01

Benzo[d]imidazole 3 and 1,2,4-triazin-5(2H)-one 6 were prepared by the reaction of starting ethyl (3-hydroxy-1H-inden-2-yl)(oxo)-acetate 2 with o-phenylenediamine and thiosemicarbazide respectively. Reaction of 1,4-dihydro-1-phenylindeno[1,2-c]pyrazole-3-carbohydrazide 8 with phenylisothiocyanate gave thiosemicarbazide 9, and its reaction with chloroacetic acid or phenacylbromides led to the formation of thiazolidinone-4-one 10 or 1,3-thiazoles 12a, b. The reactivity of hydrazide 8 towards fluorinated aldehyde, phthalic anhydride, and hydrazonoyl chlorides 15a, b was studied to give fluorinated hydrazones, imide bis-hydrazones 13-16. The newly synthesized compounds were screened for their cytotoxic activities and compounds 6, 8, 9 and 10 were found the most potentially cytotoxic. The detailed synthesis, spectroscopic and biological data are reported.

Synthesis of poly (3-hexyl thiophene-2,5-diyl) in presence of CdS nanoparticles: microscopic and spectroscopic studies

Energy Technology Data Exchange (ETDEWEB)

Nicho, M. E.; Jaimes, W. [Universidad Autonoma del Estado de Morelos, Centro de Investigacion en Ingenierias y Ciencias Aplicadas, Av. Universidad 1001, Col. Chamilpa, 62209 Cuernavaca, Morelos (Mexico); Rivas A, M. E.; Quevedo L, M. A. [University of Texas at Dallas, Department of Materials Science and Engineering, 800 West Campbell Road, Richardson, Texas 75252 (United States); Hu, H., E-mail: menicho@uaem.mx [UNAM, Instituto de Energias Renovables, 62580 Temixco, Morelos (Mexico)

2017-11-01

In this paper, the synthesis of nano composites of poly(3-hexyl thiophene-2,5-diyl) (P3HT) and cadmium sulfide (CdS) nanoparticles are reported. CdS nanoparticles were first synthesized using chemical precipitation. Then P3HT was synthesized by direct oxidation of 3-hexyl thiophene with FeCl{sub 3} as oxidant in presence of CdS nanoparticles. The goal of this work was to investigate the effect of the CdS nanoparticles during the synthesis of P3HT. The resulting films of P3HT/CdS nano composites were investigated by Fourier Transform Infrared Spectroscopy (Ft-IR), Ultraviolet-Visible Spectroscopy (UV-Vis), X-ray diffraction, Transmission electron microscopy (Tem), Atomic force microscopy (AFM) and Scanning electron microscopy (Sem). Homogeneous distribution of CdS nanoparticles in P3HT was demonstrated by Sem, AFM and Tem. Ft-IR analysis showed interaction between CdS and the S atoms of the thiophene rings. This result, together with UV-Vis spectra and XRD pattern suggest a better arrangement of the polymer chains. It is possible that the CdS nanoparticles are coupled with the unpaired electrons of S atoms in the thiophene rings through the positive delocalized charge, resulting in a more ordered P3HT polymer matrix with embedded CdS nanoparticles. (Author)

Spectroscopic study of trivalent rare earth ions in calcium nitrate hydrate melt

International Nuclear Information System (INIS)

Fujii, Toshiyuki; Asano, Hideki; Kimura, Takaumi; Yamamoto, Takeshi; Uehara, Akihiro; Yamana, Hajimu

2006-01-01

Influence of the water content to chemical status of trivalent rare earth ions in calcium nitrate hydrate melt was studied by spectroscopic techniques. Fluorescence spectrometry for Eu(III) in Ca(NO 3 ) 2 .RH 2 O and electronic absorption spectrometry for Nd(III) in Ca(NO 3 ) 2 .RH 2 O were performed for analyzing the changing coordination symmetries through the changes in their hypersensitive transitions. Raman spectroscopic study and EXAFS study were performed for Y(NO 3 ) 3 solutions and Y(III) in Ca(NO 3 ) 2 .RH 2 O for analyzing the oxygen bonding to Y(III). Luminescence lifetime study of Eu(III) and Dy(III) in Ca(NO 3 ) 2 .RH 2 O was performed for evaluating the hydration number changes. Results of these spectroscopic studies indicated that, with the decrease of water content (R), the hydration number decreases while the interaction between trivalent rare earth ion and nitrate ion increases. It was also revealed that the symmetry of the coordination sphere gets distorted gradually by this interaction

Application of spectroscopic techniques for the study of paper documents: A survey

International Nuclear Information System (INIS)

Manso, M.; Carvalho, M.L.

2009-01-01

For many centuries paper was the main material for recording cultural achievements all over the world. Paper is mostly made from cellulose with small amounts of organic and inorganic additives, which allow its identification and characterization and may also contribute to its degradation. Prior to 1850, paper was made entirely from rags, using hemp, flax and cotton fibres. After this period, due to the enormous increase in demand, wood pulp began to be commonly used as raw material, resulting in rapid degradation of paper. Spectroscopic techniques represent one of the most powerful tools to investigate the constituents of paper documents in order to establish its identification and its state of degradation. This review describes the application of selected spectroscopic techniques used for paper characterization and conservation. The spectroscopic techniques that have been used and will be reviewed include: Fourier-Transform Infrared spectroscopy, Raman spectroscopy, Nuclear Magnetic Resonance spectroscopy, X-Ray spectroscopy, Laser-based Spectroscopy, Inductively Coupled Mass Spectroscopy, Laser ablation, Atomic Absorption Spectroscopy and X-Ray Photoelectron Spectroscopy.

EEL spectroscopic tomography: Towards a new dimension in nanomaterials analysis

Energy Technology Data Exchange (ETDEWEB)

Yedra, Lluis, E-mail: llyedra@el.ub.es [Laboratory of Electron Nanoscopies (LENS)-MIND/IN2UB, Dept. d' Electronica, Universitat de Barcelona, c/ Marti Franques 1, E-08028 Barcelona (Spain); CCiT, Scientific and Technological Centers, Universitat de Barcelona, C/Lluis Sole i Sabaris 1, E-08028 Barcelona (Spain); Eljarrat, Alberto [Laboratory of Electron Nanoscopies (LENS)-MIND/IN2UB, Dept. d' Electronica, Universitat de Barcelona, c/ Marti Franques 1, E-08028 Barcelona (Spain); Arenal, Raul [Laboratorio de Microscopias Avanzadas (LMA), Instituto de Nanociencia de Aragon (INA), Universidad de Zaragoza, E-50018 Zaragoza (Spain); Fundacion ARAID, E-50004 Zaragoza (Spain); Pellicer, Eva; Cabo, Moises [Departament de Fisica, Facultat de Ciencies, Universitat Autonoma de Barcelona, E-08193 Bellaterra (Spain); Lopez-Ortega, Alberto; Estrader, Marta [CIN2(CIN-CSIC) and Universitat Autonoma de Barcelona, Catalan Institute of Nanotechnology, Campus de la UAB, E-08193 Bellaterra (Spain); Sort, Jordi [Institucio Catalana de Recerca i Estudis Avancats (ICREA), Departament de Fisica, Facultat de Ciencies, Universitat Autonoma de Barcelona, E-08193 Bellaterra (Spain); Baro, Maria Dolors [Departament de Fisica, Facultat de Ciencies, Universitat Autonoma de Barcelona, E-08193 Bellaterra (Spain); and others

2012-11-15

Electron tomography is a widely spread technique for recovering the three dimensional (3D) shape of nanostructured materials. Using a spectroscopic signal to achieve a reconstruction adds a fourth chemical dimension to the 3D structure. Up to date, energy filtering of the images in the transmission electron microscope (EFTEM) is the usual spectroscopic method even if most of the information in the spectrum is lost. Unlike EFTEM tomography, the use of electron energy-loss spectroscopy (EELS) spectrum images (SI) for tomographic reconstruction retains all chemical information, and the possibilities of this new approach still remain to be fully exploited. In this article we prove the feasibility of EEL spectroscopic tomography at low voltages (80 kV) and short acquisition times from data acquired using an aberration corrected instrument and data treatment by Multivariate Analysis (MVA), applied to Fe{sub x}Co{sub (3-x)}O{sub 4}@Co{sub 3}O{sub 4} mesoporous materials. This approach provides a new scope into materials; the recovery of full EELS signal in 3D. -- Highlights: Black-Right-Pointing-Pointer EELS-SI tomography was performed at low voltage and low acquisition times. Black-Right-Pointing-Pointer MVA has been applied for noise reduction and information extraction. Black-Right-Pointing-Pointer Tomographic reconstruction has been achieved for chemical information. Black-Right-Pointing-Pointer Elemental distribution extraction in 3D has been proved.

A convolutional neural network to filter artifacts in spectroscopic MRI.

Science.gov (United States)

Gurbani, Saumya S; Schreibmann, Eduard; Maudsley, Andrew A; Cordova, James Scott; Soher, Brian J; Poptani, Harish; Verma, Gaurav; Barker, Peter B; Shim, Hyunsuk; Cooper, Lee A D

2018-03-09

Proton MRSI is a noninvasive modality capable of generating volumetric maps of in vivo tissue metabolism without the need for ionizing radiation or injected contrast agent. Magnetic resonance spectroscopic imaging has been shown to be a viable imaging modality for studying several neuropathologies. However, a key hurdle in the routine clinical adoption of MRSI is the presence of spectral artifacts that can arise from a number of sources, possibly leading to false information. A deep learning model was developed that was capable of identifying and filtering out poor quality spectra. The core of the model used a tiled convolutional neural network that analyzed frequency-domain spectra to detect artifacts. When compared with a panel of MRS experts, our convolutional neural network achieved high sensitivity and specificity with an area under the curve of 0.95. A visualization scheme was implemented to better understand how the convolutional neural network made its judgement on single-voxel or multivoxel MRSI, and the convolutional neural network was embedded into a pipeline capable of producing whole-brain spectroscopic MRI volumes in real time. The fully automated method for assessment of spectral quality provides a valuable tool to support clinical MRSI or spectroscopic MRI studies for use in fields such as adaptive radiation therapy planning. © 2018 International Society for Magnetic Resonance in Medicine.

Application of imaging spectroscopic reflectometry for characterization of gold reduction from organometallic compound by means of plasma jet technology

Energy Technology Data Exchange (ETDEWEB)

Vodák, Jiří, E-mail: jiri.vodak@yahoo.com [Institute of Physical Engineering, Faculty of Mechanical Engineering, Brno University of Technology, Technická 2, 616 69 Brno (Czech Republic); Nečas, David [RG Plasma Technologies, CEITEC Masaryk University, Kamenice 5, 625 00 Brno (Czech Republic); Pavliňák, David [Department of Physical Electronics, Masaryk University, Kotlářská 2, 611 37 Brno (Czech Republic); Macak, Jan M [Center of Materials and Nanotechnologies, Faculty of Chemical Technology, University of Pardubice, Nám. Čs. Legií 565, 530 02 Pardubice (Czech Republic); Řičica, Tomáš; Jambor, Roman [Department of General and Inorganic Chemistry, Faculty of Chemical Technology, University of Pardubice, Studentská 573, 532 10 Pardubice (Czech Republic); Ohlídal, Miloslav [Institute of Physical Engineering, Faculty of Mechanical Engineering, Brno University of Technology, Technická 2, 616 69 Brno (Czech Republic); Institute of Physics, Faculty of Mining and Geology, VŠB – Technical University of Ostrava (Czech Republic)

2017-02-28

Highlights: • Metallic gold is reduced from an organometallic compound layer using a plasma jet. • Imaging spectroscopic reflectometry is used to locate areas with metallic gold. • The results are completed with XPS and optical microscopy observations. - Abstract: This work presents a new application of imaging spectroscopic reflectometry to determine a distribution of metallic gold in a layer of an organogold precursor which was treated by a plasma jet. Gold layers were prepared by spin coating from a solution of the precursor containing a small amount of polyvinylpyrrolidone on a microscopy glass, then they were vacuum dried. A difference between reflectivity of metallic gold and the precursor was utilized by imaging spectroscopic reflectometry to create a map of metallic gold distribution using a newly developed model of the studied sample. The basic principle of the imaging spectroscopic reflectometry is also shown together with the data acquisition principles. XPS measurements and microscopy observations were made to complete the imaging spectroscopic reflectometry results. It is proved that the imaging spectroscopic reflectometry represents a new method for quantitative evaluation of local reduction of metallic components from metaloorganic compounds.

Caulerpa racemosa: a marine green alga for eco-friendly synthesis of silver nanoparticles and its catalytic degradation of methylene blue.

Science.gov (United States)

Edison, Thomas Nesakumar Jebakumar Immanuel; Atchudan, Raji; Kamal, Chennappan; Lee, Yong Rok

2016-09-01

In this study, a simple and green method has been demonstrated for the synthesis of highly stable silver nanoparticles (AgNPs) using aqueous extract of Caulerpa racemosa (C. racemosa) as a reducing and capping agent. The formation and stability of AgNPs were studied using visual observation and UV-Visible (UV-Vis) spectroscopy. The stable AgNPs were further characterized by X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy and high resolution transmission electron microscopy (HR-TEM) with energy dispersive spectroscopic (EDS) methods. The biosynthesized AgNPs showed a sharp surface plasmon resonance peak at 441 nm in the visible region and they have extended stability which has been confirmed by the UV-Vis spectroscopic results. XRD result revealed the crystalline nature of synthesized AgNPs and they are mainly oriented in (111) plane. FT-IR studies proved that the phytoconstituents of C. racemosa protect the AgNPs from aggregation and also which are responsible for the high stability. The size of synthesized AgNPs was approximately 25 nm with distorted spherical shape, identified from the HR-TEM images. The synthesized AgNPs showed excellent catalytic activity towards degradation of methylene blue.

Spectroscopic properties of highly Nd-doped lead phosphate glass

Energy Technology Data Exchange (ETDEWEB)

Novais, A.L.F. [Instituto de Física, Universidade Federal de Alagoas, Grupo de Fotônica e Fluidos Complexos, 57072-970 Maceió, AL (Brazil); Dantas, N.O. [Laboratório de Novos Materiais Isolantes e Semicondutores (LNMIS), Instituto de Física, Universidade Federal de Uberlândia, 38400-902 Uberlândia, MG (Brazil); Guedes, I. [Departamento de Física, Universidade Federal do Ceará, Campus do PICI, Caixa Postal 6030, 60455-760 Fortaleza, CE (Brazil); Vermelho, M.V.D., E-mail: vermelho@fis.ufal.br [Instituto de Física, Universidade Federal de Alagoas, Grupo de Fotônica e Fluidos Complexos, 57072-970 Maceió, AL (Brazil)

2015-11-05

The spectroscopic characteristics of highly Nd{sup 3+}-doped lead phosphate glasses (xNd:Pb{sub 3}(PO{sub 4}){sub 2}) have been investigated. The X-ray spectra show that the matrices are glassy up to 25 wt% of Nd{sup 3+} doping. From the Judd–Ofelt analysis we observe that while the Ω{sub (2)} parameter remains constant indicating that the 4f{sup N} and 4f{sup N−1}5 d{sup 1} configurations are not affected by the Nd{sup 3+} doping, the behavior of both Ω{sub (4)} and Ω{sub (6)} changes for 15 wt% of Nd{sup 3+} doping. The reduction of the Ω{sub (6)} parameter is related to the increase of the covalence bonding between the ligands and the Nd{sup 3+} ions. At this particular concentration, the radiative lifetime has a four-fold enhancement. Such behaviors are likely to be related to a modification in the glass structure for high Nd{sup 3+} concentrations. - Graphical abstract: Highly doped lead-phosphate glass matrix, with nominal concentration of up to 25 wt%, maintain the spectroscopic properties without deterioration. The analysis concerning the point of view of Nd{sup 3+} ions showed that high concentrations only affects the rare earth electronic charge density distribution. - Highlights: • Spectroscopic characterization of Nd{sub 2}O{sub 3} highly doped lead phosphate glasses. • Phosphate glass doped with Nd{sup 3+} for applications in photonic devices. • Judd–Ofelt analysis in phosphate glasses doped with Neodymium.

Electronic properties of diphenyl-s-tetrazine and some related oligomers. An spectroscopic and theoretical study

International Nuclear Information System (INIS)

Moral, Mónica; García, Gregorio; Peñas, Antonio; Garzón, Andrés; Granadino-Roldán, José M.; Melguizo, Manuel; Fernández-Gómez, Manuel

2012-01-01

Highlights: ► We study properties of Ph 2 Tz and (PhTz) n Ph as candidates for organic electronics. ► The synthesis of Ph 2 Tz was performed through a modified Pinner-type reaction. ► IR/Raman spectra allowed to conclude that Ph 2 Tz is nearly planar in liquid phase. ► Electronic structure was studied by UV–Vis/TD-DFT methods in different solvents. ► Bandgap, E LUMO , electron mobility predict some n-type character for limit polymer. -- Abstract: This work presents a theoretical and spectroscopic study on the electronic and structural properties of the diphenyl-s-tetrazine molecule (Ph 2 Tz) and some oligomeric derivatives. Ph 2 Tz was synthesized through a variation of Pinner-type reaction which uses N-acetylcysteine as catalyst. Insight into the structure and electronic properties of the title compound was obtained through IR, Raman, UV–Vis spectra in different solvents, and theoretical calculations. Theoretical studies have been extended to different n-mers derivatives up to an ideal molecular wire through the oligomeric approximation, predicting this way electronic properties such as LUMO energy levels, electron affinity and reorganization energy in order to assess their possible applications in molecular electronics.

Improved Synthesis of 2',6'-Dihydroxy-3,4-dimethoxy Chalcone by Grinding Technique to Synthesize 5-Hydroxy-3',4'-dimethoxy Flavone

Directory of Open Access Journals (Sweden)

Elfi Susanti VH

2014-07-01

Full Text Available 5-hydroxy-3',4'-dimethoxy flavone can be efficiently synthesized in two steps via the formation of 2',6'-dihydroxy-3,4-dimethoxy chalcone with good results. 2',6'-dihydroxy-3,4-dimethoxy chalcone as reactants for synthesis of flavones was prepared through Claisen-Schmidt condensation reaction between 2,6-dihydroxyacetophenones,3,4-dimethoxybenzaldehyde and solid NaOH in mortar for 15 min. The yield of the product (70% is higher than conventional method (65%. This chalcone then oxidatively cyclized with iodine to form 5-hydroxy-3',4'-dimethoxy flavone (yield 62%. Compounds synthesized were characterized by spectroscopic (IR, 1H-NMR, and 13C-NMR.

SPT-GMOS: A GEMINI/GMOS-SOUTH SPECTROSCOPIC SURVEY OF GALAXY CLUSTERS IN THE SPT-SZ SURVEY

International Nuclear Information System (INIS)

Bayliss, M. B.; Ruel, J.; Stubbs, C. W.; Allen, S. W.; Applegate, D. E.; Ashby, M. L. N.; Bautz, M.; Benson, B. A.; Carlstrom, J. E.; Chang, C. L.; Crawford, T. M.; Bleem, L. E.; Bocquet, S.; Brodwin, M.; Capasso, R.; Chiu, I.; Cho, H-M.; Clocchiatti, A.; Crites, A. T.; Haan, T. de

2016-01-01

We present the results of SPT-GMOS, a spectroscopic survey with the Gemini Multi-Object Spectrograph (GMOS) on Gemini South. The targets of SPT-GMOS are galaxy clusters identified in the SPT-SZ survey, a millimeter-wave survey of 2500 deg 2 of the southern sky using the South Pole Telescope (SPT). Multi-object spectroscopic observations of 62 SPT-selected galaxy clusters were performed between 2011 January and 2015 December, yielding spectra with radial velocity measurements for 2595 sources. We identify 2243 of these sources as galaxies, and 352 as stars. Of the galaxies, we identify 1579 as members of SPT-SZ galaxy clusters. The primary goal of these observations was to obtain spectra of cluster member galaxies to estimate cluster redshifts and velocity dispersions. We describe the full spectroscopic data set and resulting data products, including galaxy redshifts, cluster redshifts, and velocity dispersions, and measurements of several well-known spectral indices for each galaxy: the equivalent width, W , of [O ii] λλ 3727, 3729 and H- δ , and the 4000 Å break strength, D4000. We use the spectral indices to classify galaxies by spectral type (i.e., passive, post-starburst, star-forming), and we match the spectra against photometric catalogs to characterize spectroscopically observed cluster members as a function of brightness (relative to m ⋆ ). Finally, we report several new measurements of redshifts for ten bright, strongly lensed background galaxies in the cores of eight galaxy clusters. Combining the SPT-GMOS data set with previous spectroscopic follow-up of SPT-SZ galaxy clusters results in spectroscopic measurements for >100 clusters, or ∼20% of the full SPT-SZ sample.

SPT-GMOS: A Gemini/GMOS-South Spectroscopic Survey of Galaxy Clusters in the SPT-SZ Survey

Science.gov (United States)

Bayliss, M. B.; Ruel, J.; Stubbs, C. W.; Allen, S. W.; Applegate, D. E.; Ashby, M. L. N.; Bautz, M.; Benson, B. A.; Bleem, L. E.; Bocquet, S.; Brodwin, M.; Capasso, R.; Carlstrom, J. E.; Chang, C. L.; Chiu, I.; Cho, H.-M.; Clocchiatti, A.; Crawford, T. M.; Crites, A. T.; de Haan, T.; Desai, S.; Dietrich, J. P.; Dobbs, M. A.; Doucouliagos, A. N.; Foley, R. J.; Forman, W. R.; Garmire, G. P.; George, E. M.; Gladders, M. D.; Gonzalez, A. H.; Gupta, N.; Halverson, N. W.; Hlavacek-Larrondo, J.; Hoekstra, H.; Holder, G. P.; Holzapfel, W. L.; Hou, Z.; Hrubes, J. D.; Huang, N.; Jones, C.; Keisler, R.; Knox, L.; Lee, A. T.; Leitch, E. M.; von der Linden, A.; Luong-Van, D.; Mantz, A.; Marrone, D. P.; McDonald, M.; McMahon, J. J.; Meyer, S. S.; Mocanu, L. M.; Mohr, J. J.; Murray, S. S.; Padin, S.; Pryke, C.; Rapetti, D.; Reichardt, C. L.; Rest, A.; Ruhl, J. E.; Saliwanchik, B. R.; Saro, A.; Sayre, J. T.; Schaffer, K. K.; Schrabback, T.; Shirokoff, E.; Song, J.; Spieler, H. G.; Stalder, B.; Stanford, S. A.; Staniszewski, Z.; Stark, A. A.; Story, K. T.; Vanderlinde, K.; Vieira, J. D.; Vikhlinin, A.; Williamson, R.; Zenteno, A.

2016-11-01

We present the results of SPT-GMOS, a spectroscopic survey with the Gemini Multi-Object Spectrograph (GMOS) on Gemini South. The targets of SPT-GMOS are galaxy clusters identified in the SPT-SZ survey, a millimeter-wave survey of 2500 deg2 of the southern sky using the South Pole Telescope (SPT). Multi-object spectroscopic observations of 62 SPT-selected galaxy clusters were performed between 2011 January and 2015 December, yielding spectra with radial velocity measurements for 2595 sources. We identify 2243 of these sources as galaxies, and 352 as stars. Of the galaxies, we identify 1579 as members of SPT-SZ galaxy clusters. The primary goal of these observations was to obtain spectra of cluster member galaxies to estimate cluster redshifts and velocity dispersions. We describe the full spectroscopic data set and resulting data products, including galaxy redshifts, cluster redshifts, and velocity dispersions, and measurements of several well-known spectral indices for each galaxy: the equivalent width, W, of [O II] λλ3727, 3729 and H-δ, and the 4000 Å break strength, D4000. We use the spectral indices to classify galaxies by spectral type (i.e., passive, post-starburst, star-forming), and we match the spectra against photometric catalogs to characterize spectroscopically observed cluster members as a function of brightness (relative to m⋆). Finally, we report several new measurements of redshifts for ten bright, strongly lensed background galaxies in the cores of eight galaxy clusters. Combining the SPT-GMOS data set with previous spectroscopic follow-up of SPT-SZ galaxy clusters results in spectroscopic measurements for >100 clusters, or ∼20% of the full SPT-SZ sample.

Atmospheric stellar parameters for large surveys using FASMA, a new spectral synthesis package

Science.gov (United States)

Tsantaki, M.; Andreasen, D. T.; Teixeira, G. D. C.; Sousa, S. G.; Santos, N. C.; Delgado-Mena, E.; Bruzual, G.

2018-02-01

In the era of vast spectroscopic surveys focusing on Galactic stellar populations, astronomers want to exploit the large quantity and good quality of data to derive their atmospheric parameters without losing precision from automatic procedures. In this work, we developed a new spectral package, FASMA, to estimate the stellar atmospheric parameters (namely effective temperature, surface gravity and metallicity) in a fast and robust way. This method is suitable for spectra of FGK-type stars in medium and high resolution. The spectroscopic analysis is based on the spectral synthesis technique using the radiative transfer code, MOOG. The line list is comprised of mainly iron lines in the optical spectrum. The atomic data are calibrated after the Sun and Arcturus. We use two comparison samples to test our method, (i) a sample of 451 FGK-type dwarfs from the high-resolution HARPS spectrograph; and (ii) the Gaia-ESO benchmark stars using both high and medium resolution spectra. We explore biases in our method from the analysis of synthetic spectra covering the parameter space of our interest. We show that our spectral package is able to provide reliable results for a wide range of stellar parameters, different rotational velocities, different instrumental resolutions and for different spectral regions of the VLT-GIRAFFE spectrographs, used amongst others for the Gaia-ESO survey. FASMA estimates stellar parameters in less than 15 m for high-resolution and 3 m for medium-resolution spectra. The complete package is publicly available to the community.

The DEIMOS 10K Spectroscopic Survey Catalog of the COSMOS Field

Science.gov (United States)

Hasinger, G.; Capak, P.; Salvato, M.; Barger, A. J.; Cowie, L. L.; Faisst, A.; Hemmati, S.; Kakazu, Y.; Kartaltepe, J.; Masters, D.; Mobasher, B.; Nayyeri, H.; Sanders, D.; Scoville, N. Z.; Suh, H.; Steinhardt, C.; Yang, Fengwei

2018-05-01

We present a catalog of 10,718 objects in the COSMOS field, observed through multi-slit spectroscopy with the Deep Imaging Multi-Object Spectrograph (DEIMOS) on the Keck II telescope in the wavelength range ∼5500–9800 Å. The catalog contains 6617 objects with high-quality spectra (two or more spectral features), and 1798 objects with a single spectroscopic feature confirmed by the photometric redshift. For 2024 typically faint objects, we could not obtain reliable redshifts. The objects have been selected from a variety of input catalogs based on multi-wavelength observations in the field, and thus have a diverse selection function, which enables the study of the diversity in the galaxy population. The magnitude distribution of our objects is peaked at I AB ∼ 23 and K AB ∼ 21, with a secondary peak at K AB ∼ 24. We sample a broad redshift distribution in the range 0 0.65 with chance probabilities 10 Mpc. An object-to-object comparison with a multitude of other spectroscopic samples in the same field shows that our DEIMOS sample is among the best in terms of fraction of spectroscopic failures and relative redshift accuracy. We have determined the fraction of spectroscopic blends to about 0.8% in our sample. This is likely a lower limit and at any rate well below the most pessimistic expectations. Interestingly, we find evidence for strong lensing of Lyα background emitters within the slits of 12 of our target galaxies, increasing their apparent density by about a factor of 4. The data presented herein were obtained at the W. M. Keck Observatory, which is operated as a scientific partnership among the California Institute of Technology, the University of California and the National Aeronautics and Space Administration. The Observatory was made possible by the generous financial support of the W. M. Keck Foundation.

Constraints on early-type galaxy structure from spectroscopically selected gravitational lenses

Science.gov (United States)

Bolton, Adam Stallard

2005-11-01

This thesis describes all aspects of a unique spectroscopic survey for strong galaxy-galaxy gravitational lenses: motivation, candidate selection, ground- based spectroscopic follow-up, Hubble Space Telescope imaging, data analysis, and results on the radial density profile of the lens galaxies. The lens candidates are selected from within the spectroscopic database of the Sloan Digital Sky Survey (SDSS) based on the appearance of two significantly different redshifts along the same line of sight, and lenses are confirmed within the candidate sample by follow-up imaging and spectroscopy. The sample of [approximate]20 early-type lenses presented in this thesis represents the largest single strong-lens galaxy sample discovered and published to date. These lenses probe the mass of the lens galaxies on scales roughly equal to one-half effective radius. We find a dynamical normalization between isothermal lens-model velocity dispersions and aperture-corrected SDSS stellar velocity dispersions of f = s lens /s stars = 0.95 +/- 0.03. By combining lens-model Einstein radii and de Vaucouleurs effective radii with stellar velocity dispersions through the Jeans equation, we find that the logarithmic slope [Special characters omitted.] of the density profile in our lens galaxies (r 0 ( [Special characters omitted.] ) is on average slightly steeper than isothermal ([Special characters omitted.] = 2) with a modest intrinsic scatter. Parameterizing the intrinsic distribution in [Special characters omitted.] as Gaussian, we find a maximum-likelihood mean of [Special characters omitted. ] and standard deviation of s[Special characters omitted.] = [Special characters omitted.] (68% confidence, for isotropic velocity-dispersion models). Our results rule out a single universal logarithmic density slope at >99.995% confidence. The success of this spectroscopic lens survey suggests that similar projects should be considered as an explicit science goal of future redshift surveys. (Copies

Fuel cells: spectroscopic studies in the electrocatalysis of alcohol oxidation

Directory of Open Access Journals (Sweden)

Iwasita Teresa

2002-01-01

Full Text Available Modern spectroscopic methods are useful for elucidating complex electrochemical mechanisms as those occurring during the oxidation of small organic molecules (CH3OH, HCOH, HCOOH. In the present paper it is shown the use of spectroscopic methods to study the oxidation of alcohols on platinum or Pt-based binary electrodes. These reactions are of importance in conexion with the development of anode systems for use in fuel cells. Mass spectrometry and FT infrared spectroscopy allow to establishing the reaction intermediates and products and the dependence of the amount of species on the applied potential. FTIR and scanning tunneling microscopy contribute to understand the effects of the surface structure on the rate of reaction. Examples are presented for methanol and ethanol oxidation at pure and modified Pt catalysts.

Quantum chemical calculations and spectroscopic measurements of spectroscopic and thermodynamic properties of given uranyl complexes in aqueous solutions with possible environmental and industrial applications

Directory of Open Access Journals (Sweden)

Višňak Jakub

2016-01-01

Full Text Available A brief introduction into computational methodology and preliminary results for spectroscopic (excitation energies, vibrational frequencies in ground and excited electronic states and thermodynamic (stability constants, standard enthalpies and entropies of complexation reactions properties of some 1:1, 1:2 and 1:3 uranyl sulphato- and selenato- complexes in aqueos solutions will be given. The relativistic effects are included via Effective Core Potential (ECP, electron correlation via (TDDFT/B3LYP (dispersion interaction corrected and solvation is described via explicit inclusion of one hydration sphere beyond the coordinated water molecules. We acknowledge limits of this approximate description – more accurate calculations (ranging from semi-phenomenological two-component spin-orbit coupling up to four-component Dirac-Coulomb-Breit hamiltonian and Molecular Dynamics simulations are in preparation. The computational results are compared with the experimental results from Time-resolved Laser-induced Fluorescence Spectroscopy (TRLFS and UV-VIS spectroscopic studies (including our original experimental research on this topic. In case of the TRLFS and UV-VIS speciation studies, the problem of complex solution spectra decomposition into individual components is ill-conditioned and hints from theoretical chemistry could be very important. Qualitative agreement between our quantum chemical calculations of the spectroscopic properties and experimental data was achieved. Possible applications for geochemical modelling (e.g. safety studies of nuclear waste repositories, modelling of a future mining site and analytical chemical studies (including natural samples are discussed.

Spectroscopic analysis applied to temperature measurement in plasmas

International Nuclear Information System (INIS)

Fieffe-Prevost, P.

1978-01-01

The plasma temperature is defined only if the plasma is in a state near thermodynamic equilibrium. This plasma state is analysed in detail and spectroscopic methods for measuring the temperature are discussed. As an application the hydrogen arc of the National Institute of Metrology of the Conservatoire National des Arts et Metiers (Paris) is briefly described [fr

FTIR spectroscopic studies of bacterial cellular responses to environmental factors, plant-bacterial interactions and signalling

OpenAIRE

Kamnev, Alexander A.

2008-01-01

Modern spectroscopic techniques are highly useful in studying diverse processes in microbial cells related to or incited by environmental factors. Spectroscopic data for whole cells, supramolecular structures or isolated cellular constituents can reflect structural and/or compositional changes occurring in the course of cellular metabolic responses to the effects of pollutants, environmental conditions (stress factors); nutrients, signalling molecules (communication factors), etc. This inform...

Accurate spectroscopic characterization of protonated oxirane: a potential prebiotic species in Titan's atmosphere

International Nuclear Information System (INIS)

Giacomo Ciamician, Università di Bologna, Via Selmi 2, I-40126 Bologna (Italy))" data-affiliation=" (Dipartimento di Chimica Giacomo Ciamician, Università di Bologna, Via Selmi 2, I-40126 Bologna (Italy))" >Puzzarini, Cristina; Ali, Ashraf; Biczysko, Malgorzata; Barone, Vincenzo

2014-01-01

An accurate spectroscopic characterization of protonated oxirane has been carried out by means of state-of-the-art computational methods and approaches. The calculated spectroscopic parameters from our recent computational investigation of oxirane together with the corresponding experimental data available were used to assess the accuracy of our predicted rotational and IR spectra of protonated oxirane. We found an accuracy of about 10 cm –1 for vibrational transitions (fundamentals as well as overtones and combination bands) and, in relative terms, of 0.1% for rotational transitions. We are therefore confident that the spectroscopic data provided herein are a valuable support for the detection of protonated oxirane not only in Titan's atmosphere but also in the interstellar medium.

Accurate spectroscopic characterization of protonated oxirane: a potential prebiotic species in Titan's atmosphere

Energy Technology Data Exchange (ETDEWEB)

Puzzarini, Cristina [Dipartimento di Chimica " Giacomo Ciamician," Università di Bologna, Via Selmi 2, I-40126 Bologna (Italy); Ali, Ashraf [NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Biczysko, Malgorzata; Barone, Vincenzo, E-mail: cristina.puzzarini@unibo.it [Scuola Normale Superiore, Piazza dei Cavalieri 7, I-56126 Pisa (Italy)

2014-09-10

An accurate spectroscopic characterization of protonated oxirane has been carried out by means of state-of-the-art computational methods and approaches. The calculated spectroscopic parameters from our recent computational investigation of oxirane together with the corresponding experimental data available were used to assess the accuracy of our predicted rotational and IR spectra of protonated oxirane. We found an accuracy of about 10 cm{sup –1} for vibrational transitions (fundamentals as well as overtones and combination bands) and, in relative terms, of 0.1% for rotational transitions. We are therefore confident that the spectroscopic data provided herein are a valuable support for the detection of protonated oxirane not only in Titan's atmosphere but also in the interstellar medium.

A facile synthesis of novel indole derivatives as potential antitubercular agents

Directory of Open Access Journals (Sweden)

Gulzar A. Khan

2017-11-01

Full Text Available A novel series of 5,5-dimethyl-11-phenyl-4b,5,5a,10,10a,11,11a,12-octahydro-10,11,12-triaza-indeno[2,1-b]fluorenes 3a–3l were prepared by reacting oxindole, aryl amines and acetone using dibutylamine as an organocatalyst via simultaneous Knoevenagel and Michael-type reactions. This preparation is environmentally benign, highly compatible and conveniently carried out in ethanol under mild conditions. The structures of the new compounds were determined by spectroscopic techniques, including IR, 1H NMR, 13C NMR and LCHRMS. Docking studies against an enoyl acyl carrier protein reductase predicted that the compounds possessed high binding affinity towards target molecules. The compound 3k (MIC, 40 μg/mL showed comparable activity with Isoniazid at the same concentrations against MT H37 Rv. Keywords: Green synthesis, Knoevenagel–Michael addition reaction, Dibutylamine, Antitubercular activity, Molecular docking

Synthesis, structure and solvatochromic properties of 3-cyano-4,6-diphenyl-5-(3- and 4-substituted phenylazo-2-pyridones

Directory of Open Access Journals (Sweden)

NINA TODOROVIĆ

2010-08-01

Full Text Available A series of some new pyridone arylazo dyes was synthesized from the corresponding diazonium salts and 3-cyano-4,6-diphenyl-2-pyridone using the classical reaction for the synthesis of the azo compounds. The structures of these dyes were confirmed by UV–Vis, FT-IR and 1H-NMR spectroscopic techniques. The solvatochromism of the dyes was evaluated with respect to visible absorption properties in various solvents. The effects of solvent dipolarity/polarizability and solvent/solute hydrogen bonding interactions were analyzed by means of the linear solvation energy relationship concept proposed by Kamlet and Taft. The 2-pyridone/2-hydroxypiridine tautomeric equilibration was found to depend on the substituents as well as on the solvents.

Approaches to the synthesis of mesembrine and related alkaloids

International Nuclear Information System (INIS)

Katz, R.B.

1983-10-01

After a survey of the methods reported in the literature for the synthesis of mesembrine and related octahydroindoles, a novel synthetic approach to these alkaloids is presented, based on the use of the vinylogous urethane, 1-methyl-3-(3,4-di-methoxyphenyl)-2-ethoxycarbonylmethylenepyrrolidine, and its immediate precursor, N-methyl-/3-(3,4-dimethoxyphenyl)-2-thiopyrrolidone. Since the most convenient approach to the latter compound is via the corresponding lactam, attempts to prepare this material using N-methyl-2-pyrrolidone, and using methyl 3,4-di-methoxyphenylacetate are presented. Attempts to prepare mesembrine from the 3-aryl vinylogous urethane are then presented, firstly by investigation in a series of model reactions, followed by a sequence designed to lead to mesembrine itself. The failure to prepare mesembrine from the vinylogous urethane leads to the design of a new synthetic route, the crucial step in which is an alkylation on sulphur and sulphide contraction with a halomethyl vinyl ketone, to form a vinylogous amide intermediate. In an appendix the preparation, spectroscopic properties and reactivity towards alkylation of various extended enamines are discussed

Synthesis, characterization and spectroscopic studies of the dihydrobis(1,2,3-benzotriazolylborate anion and its complexes with MCl2·py2

Directory of Open Access Journals (Sweden)

KHWAJA S. SIDDIQI

2006-11-01

Full Text Available The preparation of sodium dihydrobis(1,2,3-benzotriazolylborate was realised by refluxing one mole of sodium borohydride with two moles of 1,2,3-benzotriazole in toluene over a period of 12 h. Its complexes with MCl2·py2 [whereM=Mn(II, Fe(II, Co(II, Ni(II, Cu(II and py=pyridine] were characterized by elemental analysis as well as magnetic, spectroscopic and conductivity measurements. On the basis of these studies, it is proposed that the geometry of all the complexes is octahedral. The ligand field parameters 10 Dq, B and b show extensive overlap between the M–L orbital. The molar conductance of 10-3 M solutions of the complexes in DMSO suggest them to be non-ionic in nature.

Spectroscopic characterization of uranium in evaporation basin sediments

Science.gov (United States)

Duff, M. C.; Morris, D. E.; Hunter, D. B.; Bertsch, P. M.

2000-05-01

Evaporation ponds in the San Joaquin Valley (SJV), CA, used for the containment of irrigation drainage waters contain elevated levels of uranium (U) resulting from the extensive leaching by carbonate-rich irrigation waters of the local agricultural soils that contain low levels of naturally-occurring U. The SJV ponds are subjected to changes in redox chemistry with cycles of drying and flooding. Our past studies have shown that U in the SJV Pond 14 surface sediments is present as mostly the oxidized and soluble form, U(VI). However, we were uncertain whether the U in the soil was only present as a U oxide of mixed stoichiometry, such as U 3O 8(s) (pitchblende) or other species. Here we present characterization information, which includes wet chemical and in situ spectroscopic techniques (X-ray absorption near-edge structure (XANES) and low temperature time-resolved luminescence spectroscopies) for samples from two SJV Pond sediments. Surface sediments from SJV Pond 16 were characterized for average oxidation state of U with XANES spectroscopy. The fraction of U(VI) to U(IV) in the Pond 16 sediments decreased with depth with U(IV) being the dominant oxidation state in the 5 cm to 15 cm depth. Two luminescent U(VI) species were identified in the surface sediments from Pond 14; a U(VI)-tricarbonate phase and another phase likely comprised of U(VI)-hydroxide or hydroxycarbonate. The luminescent U(VI) population in the Pond 16 sediments is dominated by species with comparable spectral characteristics to the U(VI)-hydroxide or hydroxycarbonate species found in the Pond 14 sediments. The luminescence spectroscopic results were complemented by wet chemical U leaching methods, which involved the use of carbonate and sulfuric acid solutions and oxidizing solutions of peroxide, hypochlorite and Mn(IV). Leaching was shown to decrease the total U concentration in the sediments in all cases. However, results from luminescence studies of the residual fraction in the leached

Spectroscopic enhancement in nanoparticles embedded glasses

Energy Technology Data Exchange (ETDEWEB)

Sahar, M. R., E-mail: mrahim057@gmail.com; Ghoshal, S. K., E-mail: mrahim057@gmail.com [Advanced Optical Material Research Group, Department of Physics, Faculty of Science, Universiti Teknologi Malaysia, 81310, Skudai, Johor Bahru, Johor (Malaysia)

2014-09-25

This presentation provides an overview of the recent progress in the enhancement of the spectroscopic characteristics of the glass embedded with nanoparticles (NPs). Some of our research activities with few significantly new results are highlighted and facilely analyzed. The science and technology dealing with the manipulation of the physical properties of rare earth doped inorganic glasses by embedding metallic NPs or nanoclusters produce the so-called 'nanoglass'. Meanwhile, the spectroscopic enhancement relates the intensity of the luminescence measured at certain transition. The enhancement which expectedly due to the 'plasmonics wave' (referring to the coherent coupling of photons to free electron oscillations called plasmon) occurs at the interface between a conductor and a dielectric. Plasmonics being an emerging concept in advanced optical material of nanophotonics has given this material the ability to exploit the optical response at nanoscale and opened up a new avenue in metal-based glass optics. There is a vast array of plasmonic NPs concepts yet to be explored, with applications spanning solar cells, (bio) sensing, communications, lasers, solid-state lighting, waveguides, imaging, optical data transfer, display and even bio-medicine. Localized surface plasmon resonance (LSPR) can enhance the optical response of nanoglass by orders of magnitude as observed. The luminescence enhancement and surface enhanced Raman scattering (SERS) are new paradigm of research. The enhancement of luminescence due to the influence of metallic NPs is the recurring theme of this paper.

Practical routes to (SiH₃)₃P: applications in group IV semiconductor activation and in group III-V molecular synthesis.

Science.gov (United States)

Tice, Jesse B; Chizmeshya, A V G; Tolle, J; D' Costa, V R; Menendez, J; Kouvetakis, J

2010-05-21

The (SiH₃)₃P hydride is introduced as a practical source for n-doping of group IV semiconductors and as a highly-reactive delivery agent of -(SiH₃)₂P functionalities in exploratory synthesis. In contrast to earlier methods, the compound is produced here in high purity quantitative yields via a new single-step method based on reactions of SiH₃Br and (Me₃Sn)₃P, circumventing the need for toxic and unstable starting materials. As an initial demonstration of its utility we synthesized monosubstituted Me₂M-P(SiH₃)₂ (M = Al, Ga, In) derivatives of Me₃M containing the (SiH₃)₂P ligand for the first time, in analogy to the known Me₂M-P(SiMe₃)₂ counterparts. A dimeric structure of Me₂M-P(SiH₃)₂ is proposed on the basis of spectroscopic characterizations and quantum chemical simulations. Next, in the context of materials synthesis, the (SiH₃)₃P compound was used to dope germanium for the first time by building a prototype p(++)Si(100)/i-Ge/n-Ge photodiode structure. The resultant n-type Ge layers contained active carrier concentrations of 3-4 × 10¹⁹ atoms cm⁻³ as determined by spectroscopic ellipsometry and confirmed by SIMS. Strain analysis using high resolution XRD yielded a Si content of 4 × 10²⁰ atoms cm⁻³ in agreement with SIMS and within the range expected for incorporating Si₃P type units into the diamond cubic Ge matrix. Extensive characterizations for structure, morphology and crystallinity indicate that the Si co-dopant plays essentially a passive role and does not compromise the device quality of the host material nor does it fundamentally alter its optical properties.

Synthesis, spectroscopic characterization, biological screenings, DNA binding study and POM analyses of transition metal carboxylates

Science.gov (United States)

Uddin, Noor; Sirajuddin, Muhammad; Uddin, Nizam; Tariq, Muhammad; Ullah, Hameed; Ali, Saqib; Tirmizi, Syed Ahmed; Khan, Abdur Rehman

2015-04-01

This article contains the synthesis of a novel carboxylic acid derivative, its transition metal complexes and evaluation of biological applications. Six carboxylate complexes of transition metals, Zn(II) and Hg(II), have been successfully synthesized and characterized by FT-IR and NMR (1H, 13C). The ligand, HL, (4-[(2,6-Diethylphenyl)amino]-4-oxobutanoic acid) was also characterized by single crystal X-ray analysis. The complexation occurs via oxygen atoms of the carboxylate moiety. FT-IR date show the bidentate nature of the carboxylate moiety of the ligand as the Δν value in all complexes is less than that of the free ligand. The ligand and its complexes were screened for antifungal and antileishmanial activities. The results showed that the ligand and its complexes are active with few exceptions. UV-visible spectroscopy and viscometry results reveal that the ligand and its complexes interact with the DNA via intercalative mode of interaction. A new and efficient strategy to identify the pharmacophores and anti-pharmacophores sites in carboxylate derivatives for the antibacterial/antifungal activity using Petra, Osiris and Molinspiration (POM) analyses was also carried out.

Vibrational spectroscopic study of fluticasone propionate

Science.gov (United States)

Ali, H. R. H.; Edwards, H. G. M.; Kendrick, J.; Scowen, I. J.

2009-03-01

Fluticasone propionate is a synthetic glucocorticoid with potent anti-inflammatory activity that has been used effectively in the treatment of chronic asthma. The present work reports a vibrational spectroscopic study of fluticasone propionate and gives proposed molecular assignments on the basis of ab initio calculations using BLYP density functional theory with a 6-31G* basis set and vibrational frequencies predicted within the quasi-harmonic approximation. Several spectral features and band intensities are explained. This study generated a library of information that can be employed to aid the process monitoring of fluticasone propionate.

Emission spectroscopic 15N analysis 1985

International Nuclear Information System (INIS)

Meier, G.

1986-01-01

The state of the art of emission spectroscopic 15 N analysis is demonstrated taking the NOI-6e 15 N analyzer as an example. The analyzer is equipped with a microcomputer to ensure a high operational comfort, computer control, and both data acquisition and data processing. In small amounts of nitrogen-containing substances (10 to 50 μg N 2 ) the 15 N abundance can be very quickly determined in standard discharge tubes or in aqueous ammonium salt solutions with a standard deviation less than 0.6 percent

Spectroscopic amplifier for pin diode; Amplificador espectroscopico para diodo Pin

Energy Technology Data Exchange (ETDEWEB)

Alonso M, M. S.; Hernandez D, V. M.; Vega C, H. R., E-mail: bebe.luna_s@hotmail.com [Universidad Autonoma de Zacatecas, Unidad Academica de Estudios Nucleares, Cipres No. 10, Fracc. La Penuela, 98068 Zacatecas (Mexico)

2014-10-15

The photodiode remains the basic choice for the photo-detection and is widely used in optical communications, medical diagnostics and field of corpuscular radiation. In detecting radiation it has been used for monitoring radon and its progeny and inexpensive spectrometric systems. The development of a spectroscopic amplifier for Pin diode is presented which has the following characteristics: canceler Pole-Zero (P/Z) with a time constant of 8 μs; constant gain of 57, suitable for the acquisition system; 4th integrator Gaussian order to waveform change of exponential input to semi-Gaussian output and finally a stage of baseline restorer which prevents Dc signal contribution to the next stage. The operational amplifier used is the TLE2074 of BiFET technology of Texas Instruments with 10 MHz bandwidth, 25 V/μs of slew rate and a noise floor of 17 nv/(Hz)1/2. The integrated circuit has 4 operational amplifiers and in is contained the total of spectroscopic amplifier that is the goal of electronic design. The results show like the exponential input signal is converted to semi-Gaussian, modifying only the amplitude according to the specifications in the design. The total system is formed by the detector, which is the Pin diode, a sensitive preamplifier to the load, the spectroscopic amplifier that is what is presented and finally a pulse height analyzer (Mca) which is where the spectrum is shown. (Author)

Spectroscopic and electron-ion collision data for plasma impurities

International Nuclear Information System (INIS)

Faenov, A.; Marchand, R.; Tawara, H.; Vainshtein, L.; Wiese, W.

1992-01-01

This Working Group Report briefly reviews and summarizes the available spectroscopic and electron-ion collision data for plasma impurities. Included are lithium, neon, and argon, which, although they are not plasma impurities per se, are introduced into the plasma through the application of diagnostic techniques. 32 refs, 2 tabs

AKARI INFRARED CAMERA SURVEY OF THE LARGE MAGELLANIC CLOUD. II. THE NEAR-INFRARED SPECTROSCOPIC CATALOG

International Nuclear Information System (INIS)

Shimonishi, Takashi; Onaka, Takashi; Kato, Daisuke; Sakon, Itsuki; Ita, Yoshifusa; Kawamura, Akiko; Kaneda, Hidehiro

2013-01-01

We performed a near-infrared spectroscopic survey toward an area of ∼10 deg 2 of the Large Magellanic Cloud (LMC) with the infrared satellite AKARI. Observations were carried out as part of the AKARI Large-area Survey of the Large Magellanic Cloud (LSLMC). The slitless multi-object spectroscopic capability of the AKARI/IRC enabled us to obtain low-resolution (R ∼ 20) spectra in 2-5 μm for a large number of point sources in the LMC. As a result of the survey, we extracted about 2000 infrared spectra of point sources. The data are organized as a near-infrared spectroscopic catalog. The catalog includes various infrared objects such as young stellar objects (YSOs), asymptotic giant branch (AGB) stars, supergiants, and so on. It is shown that 97% of the catalog sources have corresponding photometric data in the wavelength range from 1.2 to 11 μm, and 67% of the sources also have photometric data up to 24 μm. The catalog allows us to investigate near-infrared spectral features of sources by comparison with their infrared spectral energy distributions. In addition, it is estimated that about 10% of the catalog sources are observed at more than two different epochs. This enables us to study a spectroscopic variability of sources by using the present catalog. Initial results of source classifications for the LSLMC samples are presented. We classified 659 LSLMC spectra based on their near-infrared spectral features by visual inspection. As a result, it is shown that the present catalog includes 7 YSOs, 160 C-rich AGBs, 8 C-rich AGB candidates, 85 O-rich AGBs, 122 blue and yellow supergiants, 150 red super giants, and 128 unclassified sources. Distributions of the classified sources on the color-color and color-magnitude diagrams are discussed in the text. Continuous wavelength coverage and high spectroscopic sensitivity in 2-5 μm can only be achieved by space observations. This is an unprecedented large-scale spectroscopic survey toward the LMC in the near

Extracellular Synthesis of Silver Nanoparticles by Ralstonia sp. SM8 Isolated from the Sarcheshmeh Copper Mine

Directory of Open Access Journals (Sweden)

Morahem Ashengroph

2014-04-01

Full Text Available Introduction: The biological synthesis of nanoparticles has gained enormous importance due to the development of clean and environmentally-friendly processes. Silver is highly toxic to microbial cells, Nevertheless, it has been reported that several microorganisms are silver resistance and corroborate the microbial reduction of water soluble Ag+ to Ag0 nanoparticles. In this study, native strains of bacteria screen for use as biocatalysts for extracellular synthesis of silver nanoparticles. Materials and methods: Eight different strains of bacteria exhibiting high silver tolerance were isolated from collecting soil samples from copper and gold mines and characterized using morphological observations and preliminary biochemical tests. The bacterial strains in the presence of 1 g/l Ag+ solution at pH 7 were incubated at 28º C for 48 h in an orbital shaker. The silver nanoparticles formation was investigated by visual observations (changing the color of the reaction solution, spectroscopic techniques and microscopic observations. Results: Among the 8 strains giving high Ag+ tolerance, the strain SM8, isolated from the Sarcheshmeh Copper Mine, Kerman, showed the capability of promoting the formation extracellular Ag nanoparticles. The strain was selected and identified as Ralstonia sp. SM8 (GenBank accession number KF264453 based on morphological and biochemical characteristics and its molecular phylogenetic analysis. Results obtained by visual observations, spectral data achieved from UV–vis, XRD spectrum and SEM micrographs revealed the extracellular formation of spherical silver nanoparticles in the size range of 20-50 nm with the culture supernatants of Ralstonia sp. SM8. Discussion and conclusion: Based on the results obtained, fast and extracellular synthesis of silver nanoparticles, without the need for complicated extraction steps, can be taken by using the culture supernatants of Ralstonia sp. SM8. The current study is the first report

Identification and Spectroscopic Characterization of Nonheme Iron(III) Hypochlorite Intermediates

NARCIS (Netherlands)

Draksharapu, Apparao; Angelone, Davide; Quesne, Matthew G.; Padamati, Sandeep K.; Gomez, Laura; Hage, Ronald; Costas, Miquel; Browne, Wesley R.; de Visser, Sam P.

2015-01-01

Fe-III-hypohalite complexes have been implicated in a wide range of important enzyme-catalyzed halogenation reactions including the biosynthesis of natural products and antibiotics and post-translational modification of proteins. The absence of spectroscopic data on such species precludes their

Laser spectroscopic analysis in atmospheric pollution research

CSIR Research Space (South Africa)

Forbes, PBC

2008-01-01

Full Text Available stream_source_info ForbesP_2008.pdf.txt stream_content_type text/plain stream_size 3174 Content-Encoding ISO-8859-1 stream_name ForbesP_2008.pdf.txt Content-Type text/plain; charset=ISO-8859-1 Laser spectroscopic... Department and a CSIR National Laser Centre rental pool programme grant-holder, is involved in research into a novel method of monitoring atmospheric PAHs. The rental pool programme gives South African tertiary education institutions access to an array...

Dithieno[3,2-a:2',3'-c]phenazine-based Chemical Probe for Anions: A Spectroscopic Study of Binding

KAUST Repository

El-Assaad, Tarek H.

2015-04-27

The synthesis of a new anion-responsive molecule N,N\\'-(2,5-bis(4-(tert-butyl)phenyl)dithieno[3,2-a:2\\',3\\'-c]phenazine-9,10-diyl)bis(4-methylbenzenesulfonamide) (1) is reported. The sensitivities of the spectroscopic properties of 1 in the presence of various anions were examined using UV-vis absorption spectroscopy, fluorescence and 1H NMR titration experiments. Strong binding of 1 to carboxylate, cyanide, fluoride and dihydrogen phosphate anions results in an increase in quantum yield for emission of 1, and changes in its 1H NMR chemical shifts. A significant electrostatic interaction of the tetrabutylammonium cation with 1, upon strong binding with the counter anion, was also indicated by the chemical shifts observed in the 1H NMR titrations. Binding constants of 1 to anions are also calculated based on the binding isotherms derived from NMR and UV-Vis titrations. DFT calculations show that the anion does not significantly impact the HOMO/LUMO levels (and subsequently the S0 -> S1 transition), but rather changes the strength of the S0 -> S2 transition, which accounts for the observed changes in the UV-vis spectra.

Synthesis, characterization and biological activity studies of mixed ...

African Journals Online (AJOL)

The complexes were characterized using some physical techniques such as melting point, solubility, conductivity measurement and spectroscopic analyses such as UV-Visible spectroscopy, Atomic absorption spectroscopy, and Infrared spectroscopy. Based on the physical and spectroscopic results, the coordination of the ...

Synthesis and characterization of semi-IPNs based on PVP and PLLA; Sintese e caracterizacao de semi-IPNs envolvendo os homopolimeros PVP e PLLA

Energy Technology Data Exchange (ETDEWEB)

Camilo, A.P.R.; Mano, V., E-mail: mano@ufsj.edu.b [Universidade Federal de Sao Joao del Rei (UFSJ), MG (Brazil). Dept. de Ciencias Naturais; Felisberti, M.I. [Universidade Estadual de Campinas (IQ/UNICAMP), SP (Brazil). Inst. de Quimica

2010-07-01

The specific interest in the synthesis of semi-IPNs based on PLLA and PVP homopolymers due to the fact these are biodegradable and biocompatible, which allows us to infer applications in the medical field as sutures, implants, matrices for controlled release of drugs etc. The objective was to prepare a multicomponent material amphiphile in the form of semi-interpenetrating polymer networks, based on poly (L-lactide), PLLA, hydrophobic homopolymer, and poly (vinylpyrrolidone), PVP, hydrophilic component. The preparation of semi-IPN combined the polymerization and crosslinking of N-vinylpyrrolidone in the presence of poly (L-lactide). The products were characterized by spectroscopic and thermal methods. (author)

Optical spectroscopic elucidation of beta-turns in disulfide bridged cyclic tetrapeptides.

Science.gov (United States)

Borics, Attila; Murphy, Richard F; Lovas, Sándor

2007-01-01

Vibrational circular dichroism (VCD) spectroscopic features of type II beta-turns were characterized previously, but, criteria for differentiation between beta-turn types had not been established yet. Model tetrapeptides, cyclized through a disulfide bridge, were designed on the basis of previous experimental results and the observed incidence of amino acid residues in the i + 1 and i + 2 positions in beta-turns, to determine the features of VCD spectra of type I and II beta-turns. The results were correlated with electronic circular dichroism (ECD) spectra and VCD spectra calculated from conformational data obtained by molecular dynamics (MD) simulations. All cyclic tetrapeptides yielded VCD signals with a higher frequency negative and a lower frequency positive couplet with negative lobes overlapping. MD simulations confirmed the conformational homogeneity of these peptides in solution. Comparison with ECD spectroscopy, MD, and quantum chemical calculation results suggested that the low frequency component of VCD spectra originating from the tertiary amide vibrations could be used to distinguish between types of beta-turn structures. On the basis of this observation, VCD spectroscopic features of type II and VIII beta-turns and ECD spectroscopic properties of a type VIII beta-turn were suggested. The need for independent experimental as well as theoretical investigations to obtain decisive conformational information was recognized. Copyright 2006 Wiley Periodicals, Inc.

PHOTOMETRIC AND SPECTROSCOPIC PROPERTIES OF NOVAE IN THE LARGE MAGELLANIC CLOUD

International Nuclear Information System (INIS)

Shafter, A. W.

2013-01-01

The photometric and spectroscopic properties of the 43 known LMC nova candidates are summarized and reviewed. Of these, photometric data sufficient to establish decline rates are available for 29 novae, while spectroscopic data sufficient to establish the spectroscopic classes are available for 18 systems. Half of the 18 novae belong to the Fe II class, with the remaining nine belonging to either the He/N or the Fe IIb classes. As seen in previous nova studies of M31 and M33, the He/N and Fe IIb novae have on average faster photometric developments than do their Fe II counterparts. Overall, the available photometry confirms earlier studies, and shows conclusively that LMC novae have faster rates of decline than do novae in the Galaxy and M31. It appears that the increased fraction of faster, He/N and Fe IIb novae observed in the LMC compared with M31 is almost certainly the result of differences in the underlying stellar population between the two galaxies. We propose that the younger population seen in the LMC compared with M31's bulge (where most of the novae are found), produces progenitor binaries with higher average white dwarf masses. The higher mean white dwarf mass not only produces a larger fraction of fast, He/N novae compared with M31, but also results in a relatively large recurrent nova population.

THE APOKASC CATALOG: AN ASTEROSEISMIC AND SPECTROSCOPIC JOINT SURVEY OF TARGETS IN THE KEPLER FIELDS

Energy Technology Data Exchange (ETDEWEB)

Pinsonneault, Marc H.; Epstein, Courtney; Johnson, Jennifer A. [Department of Astronomy, The Ohio State University, Columbus, OH 43210 (United States); Elsworth, Yvonne; Chaplin, William J. [University of Birmingham, School of Physics and Astronomy, Edgbaston, Birmingham B15 2TT (United Kingdom); Hekker, Saskia; Silva Aguirre, Victor; Stello, Dennis [Stellar Astrophysics Centre, Department of Physics and Astronomy, Aarhus University, Ny Munkegade 120, DK-8000 Aarhus C (Denmark); Mészáros, Sz. [Astronomy Department, Indiana University, Bloomington, IN 47405 (United States); García, Rafael A.; Beck, Paul [Laboratoire AIM, CEA/DSM-CNRS—Université Denis Diderot-IRFU/SAp, F-91191 Gif-sur-Yvette Cedex (France); Holtzman, Jon [Department of Astronomy, MSC 4500, New Mexico State University, P.O. Box 30001, Las Cruces, NM 88003 (United States); Mathur, Savita [Space Science Institute, 4750 Walnut street, Suite 205, Boulder, CO 80301 (United States); García Pérez, Ana [Department of Astronomy, University of Virginia, P.O. Box 400325, Charlottesville, VA 22904-4325 (United States); Girardi, Léo [Osservatorio Astronomico di Padova—INAF, Vicolo dell' Osservatorio 5, I-35122 Padova (Italy); Basu, Sarbani [Department of Astronomy, Yale University, P.O. Box 208101, New Haven, CT 06520-8101 (United States); Shetrone, Matthew [University of Texas at Austin, McDonald Observatory, 32 Fowlkes Road, TX 79734-3005 (United States); Allende Prieto, Carlos [Instituto de Astrofsica de Canarias (IAC), C/Va Lactea, s/n, E-38200 La Laguna, Tenerife (Spain); An, Deokkeun [Department of Science Education, Ewha Womans University, Seoul (Korea, Republic of); Beers, Timothy C., E-mail: pinsonneault.1@osu.edu [Department of Physics, University of Notre Dame, 225 Nieuwland Science Hall, Notre Dame, IN 46656 (United States); and others

2015-01-01

We present the first APOKASC catalog of spectroscopic and asteroseismic properties of 1916 red giants observed in the Kepler fields. The spectroscopic parameters provided from the Apache Point Observatory Galactic Evolution Experiment project are complemented with asteroseismic surface gravities, masses, radii, and mean densities determined by members of the Kepler Asteroseismology Science Consortium. We assess both random and systematic sources of error and include a discussion of sample selection for giants in the Kepler fields. Total uncertainties in the main catalog properties are of the order of 80 K in T {sub eff}, 0.06 dex in [M/H], 0.014 dex in log g, and 12% and 5% in mass and radius, respectively; these reflect a combination of systematic and random errors. Asteroseismic surface gravities are substantially more precise and accurate than spectroscopic ones, and we find good agreement between their mean values and the calibrated spectroscopic surface gravities. There are, however, systematic underlying trends with T {sub eff} and log g. Our effective temperature scale is between 0 and 200 K cooler than that expected from the infrared flux method, depending on the adopted extinction map, which provides evidence for a lower value on average than that inferred for the Kepler Input Catalog (KIC). We find a reasonable correspondence between the photometric KIC and spectroscopic APOKASC metallicity scales, with increased dispersion in KIC metallicities as the absolute metal abundance decreases, and offsets in T {sub eff} and log g consistent with those derived in the literature. We present mean fitting relations between APOKASC and KIC observables and discuss future prospects, strengths, and limitations of the catalog data.

In situ spectroscopic ellipsometry as a surface sensitive tool to probe thin film growth

International Nuclear Information System (INIS)

Liu, C.

1999-01-01

Sputtered thin film and multilayer x-ray mirrors are made routinely at the Advanced Photon Source (APS) for the APS users. Precise film growth control and characterization are very critical in fabricating high-quality x-ray mirrors. Film thickness calibrations are carried out using in situ and ex situ spectroscopic ellipsometry, interferometry, and x-ray scattering. To better understand the growth and optical properties of different thin film systems, we have carried out a systematic study of sputtered thin films of Au, Rh, Pg Pd, Cu, and Cr, using in situ ellipsometry. Multiple data sets were obtained in situ for each film material with incremental thicknesses and were analyzed with their correlation in mind. We found that in situ spectroscopic ellipsometry as a surface-sensitive tool can also be used to probe the growth and morphology of the thin film system. This application of in situ spectroscopic ellipsometry for metal thin film systems will be discussed

TOWARD A SPECTROSCOPIC CENSUS OF WHITE DWARFS WITHIN 40 pc OF THE SUN

International Nuclear Information System (INIS)

Limoges, M.-M.; Bergeron, P.; Lépine, S.

2013-01-01

We present the preliminary results of a survey aimed at significantly increasing the range and completeness of the local census of spectroscopically confirmed white dwarfs. The current census of nearby white dwarfs is reasonably complete only to about 20 pc of the Sun, a volume that includes around 130 white dwarfs, a sample too small for detailed statistical analyses. This census is largely based on follow-up investigations of stars with very large proper motions. We describe here the basis of a method that will lead to a catalog of white dwarfs within 40 pc of the Sun and north of the celestial equator, thus increasing by a factor of eight the extent of the northern sky census. White dwarf candidates are identified from the SUPERBLINK proper motion database, allowing us to investigate stars down to a proper motion limit μ > 40 mas yr –1 , while minimizing the kinematic bias for nearby objects. The selection criteria and distance estimates are based on a combination of color-magnitude and reduced proper motion diagrams. Our follow-up spectroscopic observation campaign has so far uncovered 193 new white dwarfs, among which we identify 127 DA (including 9 DA+dM and 4 magnetic), 1 DB, 56 DC, 3 DQ, and 6 DZ stars. We perform a spectroscopic analysis on a subsample of 84 DAs, and provide their atmospheric parameters. In particular, we identify 11 new white dwarfs with spectroscopic distances within 25 pc of the Sun, including five candidates to the D < 20 pc subset.

Breath Analysis Using Laser Spectroscopic Techniques: Breath Biomarkers, Spectral Fingerprints, and Detection Limits

Directory of Open Access Journals (Sweden)

Peeyush Sahay

2009-10-01

Full Text Available Breath analysis, a promising new field of medicine and medical instrumentation, potentially offers noninvasive, real-time, and point-of-care (POC disease diagnostics and metabolic status monitoring. Numerous breath biomarkers have been detected and quantified so far by using the GC-MS technique. Recent advances in laser spectroscopic techniques and laser sources have driven breath analysis to new heights, moving from laboratory research to commercial reality. Laser spectroscopic detection techniques not only have high-sensitivity and high-selectivity, as equivalently offered by the MS-based techniques, but also have the advantageous features of near real-time response, low instrument costs, and POC function. Of the approximately 35 established breath biomarkers, such as acetone, ammonia, carbon dioxide, ethane, methane, and nitric oxide, 14 species in exhaled human breath have been analyzed by high-sensitivity laser spectroscopic techniques, namely, tunable diode laser absorption spectroscopy (TDLAS, cavity ringdown spectroscopy (CRDS, integrated cavity output spectroscopy (ICOS, cavity enhanced absorption spectroscopy (CEAS, cavity leak-out spectroscopy (CALOS, photoacoustic spectroscopy (PAS, quartz-enhanced photoacoustic spectroscopy (QEPAS, and optical frequency comb cavity-enhanced absorption spectroscopy (OFC-CEAS. Spectral fingerprints of the measured biomarkers span from the UV to the mid-IR spectral regions and the detection limits achieved by the laser techniques range from parts per million to parts per billion levels. Sensors using the laser spectroscopic techniques for a few breath biomarkers, e.g., carbon dioxide, nitric oxide, etc. are commercially available. This review presents an update on the latest developments in laser-based breath analysis.

Investigations on synthesis, coordination behaviour and actinide recovery of unexplored phosphine oxides

International Nuclear Information System (INIS)

Veerashekhar Goud, E.; Pavankumar, B.B.; Das, Dhrubajyothi

2016-01-01

The search for the development of an optimum extractant for effective separation of a particular metal from a mixture is an active field of research in both chemistry and chemical engineering. These extractants find extensive application in extractive metallurgy and in nuclear fuel cycle (for the separation of actinides from other fission products). In the case of the latter, solvent extraction and ion exchange are two widely employed separation techniques. In this connection, the present paper reports synthesis and structural characterization of various new phosphine oxide derivatives. The coordination behavior of these ligands is studied with some selected lanthanides and actinides shows the proposed structures of La(III) and Th(IV) metal complexes. The purity and structural characterization of the ligands and their corresponding metal complexes are analyzed by various analytical and spectroscopic techniques. Additionally, we have applied Density functional theory (DFT) calculations to understand the electronic structure of some metal complexes formed during the extraction process. (author)

NARROW-LINE X-RAY-SELECTED GALAXIES IN THE CHANDRA -COSMOS FIELD. I. OPTICAL SPECTROSCOPIC CATALOG

Energy Technology Data Exchange (ETDEWEB)

Pons, E.; Watson, M. G. [University of Leicester, Leicester (United Kingdom); Elvis, M.; Civano, F. [Harvard-Smithsonian Center for Astrophysics, Cambridge, MA (United States)

2016-04-20

The COSMOS survey is a large and deep survey with multiwavelength observations of sources from X-rays to the UV, allowing an extensive study of their properties. The central 0.9 deg{sup 2} of the COSMOS field have been observed by Chandra with a sensitivity up to 1.9 × 10{sup −16} erg cm{sup −2} s{sup −1} in the full (0.5–10 keV) band. Photometric and spectroscopic identification of the Chandra -COSMOS (C-COSMOS) sources is available from several catalogs and campaigns. Despite the fact that the C-COSMOS galaxies have a reliable spectroscopic redshift in addition to a spectroscopic classification, the emission-line properties of this sample have not yet been measured. We present here the creation of an emission-line catalog of 453 narrow-line sources from the C-COSMOS spectroscopic sample. We have performed spectral fitting for the more common lines in galaxies ([O ii] λ 3727, [Ne iii] λ 3869, H β , [O iii] λλ 4959, 5007, H α , and [N ii] λλ 6548, 6584). These data provide an optical classification for 151 (i.e., 33%) of the C-COSMOS narrow-line galaxies based on emission-line diagnostic diagrams.

SSGSS: THE SPITZER–SDSS–GALEX SPECTROSCOPIC SURVEY

International Nuclear Information System (INIS)

O'Dowd, Matthew J.; Schiminovich, David; Johnson, Benjamin D.; Treyer, Marie A.; Martin, Christopher D.; Wyder, Ted K.; Charlot, Stéphane; Heckman, Timothy M.; Martins, Lucimara P.; Seibert, Mark; Van der Hulst, J. M.

2011-01-01

The Spitzer-SDSS-GALEX Spectroscopic Survey (SSGSS) provides a new sample of 101 star-forming galaxies at z < 0.2 with unprecedented multi-wavelength coverage. New mid- to far-infrared spectroscopy from the Spitzer Space Telescope is added to a rich suite of previous imaging and spectroscopy, including ROSAT, Galaxy Evolution Explorer, Sloan Digital Sky Survey, Two Micron All Sky Survey, and Spitzer/SWIRE. Sample selection ensures an even coverage of the full range of normal galaxy properties, spanning two orders of magnitude in stellar mass, color, and dust attenuation. In this paper we present the SSGSS data set, describe the science drivers, and detail the sample selection, observations, data reduction, and quality assessment. Also in this paper, we compare the shape of the thermal continuum and the degree of silicate absorption of these typical, star-forming galaxies to those of starburst galaxies. We investigate the link between star formation rate, infrared luminosity, and total polycyclic aromatic hydrocarbon luminosity, with a view to calibrating the latter for spectral energy distribution models in photometric samples and at high redshift. Last, we take advantage of the 5-40 μm spectroscopic and far-infrared photometric coverage of this sample to perform detailed fitting of the Draine et al. dust models, and investigate the link between dust mass and star formation history and active galactic nucleus properties.

EPSILON AURIGAE: AN IMPROVED SPECTROSCOPIC ORBITAL SOLUTION

International Nuclear Information System (INIS)

Stefanik, Robert P.; Torres, Guillermo; Lovegrove, Justin; Latham, David W.; Zajac, Joseph; Pera, Vivian E.; Mazeh, Tsevi

2010-01-01

A rare eclipse of the mysterious object ε Aurigae will occur in 2009-2011. We report an updated single-lined spectroscopic solution for the orbit of the primary star based on 20 years of monitoring at the CfA, combined with historical velocity observations dating back to 1897. There are 518 new CfA observations obtained between 1989 and 2009. Two solutions are presented. One uses the velocities outside the eclipse phases together with mid-times of previous eclipses, from photometry dating back to 1842, which provide the strongest constraint on the ephemeris. This yields a period of 9896.0 ± 1.6 days (27.0938 ± 0.0044 years) with a velocity semi-amplitude of 13.84 ± 0.23 km s -1 and an eccentricity of 0.227 ± 0.011. The middle of the current ongoing eclipse predicted by this combined fit is JD 2,455,413.8 ± 4.8, corresponding to 2010 August 5. If we use only the radial velocities, we find that the predicted middle of the current eclipse is nine months earlier. This would imply that the gravitating companion is not the same as the eclipsing object. Alternatively, the purely spectroscopic solution may be biased by perturbations in the velocities due to the short-period oscillations of the supergiant.

Spectroscopic characterization approach to study surfactants effect on ZnO 2 nanoparticles synthesis by laser ablation process

Science.gov (United States)

Drmosh, Q. A.; Gondal, M. A.; Yamani, Z. H.; Saleh, T. A.

2010-05-01

Zinc peroxide nanoparticles having grain size less than 5 nm were synthesized using pulsed laser ablation in aqueous solution in the presence of different surfactants and solid zinc target in 3% H 2O 2. The effect of surfactants on the optical and structure of ZnO 2 was studied by applying different spectroscopic techniques. Structural properties and grain size of the synthesized nanoparticles were studied using XRD method. The presence of the cubic phase of zinc peroxide in all samples was confirmed with XRD, and the grain sizes were 4.7, 3.7, 3.3 and 2.8 nm in pure H 2O 2, and H 2O 2 mixed with SDS, CTAB and OGM respectively. For optical characterization, FTIR transmittance spectra of ZnO 2 nanoparticles prepared with and without surfactants show a characteristic ZnO 2 absorption at 435-445 cm -1. FTIR spectrum revealed that the adsorbed surfactants on zinc peroxide disappeared in case of CTAB and OGM while it appears in case of SDS. This could be due to high critical micelles SDS concentration comparing with others which is attributed to the adsorption anionic nature of this surfactant. Both FTIR and UV-vis spectra show a red shift in the presence of SDS and blue shift in the presence of CTAB and OGM. The blue shift in the absorption edge indicates the quantum confinement property of nanoparticles. The zinc peroxide nanoparticles prepared in additives-free media was also characterized by Raman spectra which show the characteristic peaks at 830-840 and 420-440 cm -1.

Spectroscopic characterization approach to study surfactants effect on ZnO2 nanoparticles synthesis by laser ablation process

International Nuclear Information System (INIS)

Drmosh, Q.A.; Gondal, M.A.; Yamani, Z.H.; Saleh, T.A.

2010-01-01

Zinc peroxide nanoparticles having grain size less than 5 nm were synthesized using pulsed laser ablation in aqueous solution in the presence of different surfactants and solid zinc target in 3% H 2 O 2 . The effect of surfactants on the optical and structure of ZnO 2 was studied by applying different spectroscopic techniques. Structural properties and grain size of the synthesized nanoparticles were studied using XRD method. The presence of the cubic phase of zinc peroxide in all samples was confirmed with XRD, and the grain sizes were 4.7, 3.7, 3.3 and 2.8 nm in pure H 2 O 2 , and H 2 O 2 mixed with SDS, CTAB and OGM respectively. For optical characterization, FTIR transmittance spectra of ZnO 2 nanoparticles prepared with and without surfactants show a characteristic ZnO 2 absorption at 435-445 cm -1 . FTIR spectrum revealed that the adsorbed surfactants on zinc peroxide disappeared in case of CTAB and OGM while it appears in case of SDS. This could be due to high critical micelles SDS concentration comparing with others which is attributed to the adsorption anionic nature of this surfactant. Both FTIR and UV-vis spectra show a red shift in the presence of SDS and blue shift in the presence of CTAB and OGM. The blue shift in the absorption edge indicates the quantum confinement property of nanoparticles. The zinc peroxide nanoparticles prepared in additives-free media was also characterized by Raman spectra which show the characteristic peaks at 830-840 and 420-440 cm -1 .

Synthesis and characterization of tunable coumarin- linked glasses as new class of organic/inorganic phosphors

Energy Technology Data Exchange (ETDEWEB)

Luridiana, Alberto; Pretta, Gianluca; Secci, Francesco; Frongia, Angelo [Dipartimento di Scienze Chimiche e Geologiche, Università degli Studi di Cagliari, Complesso universitario di Monserrato, SS 554, bivio per Sestu, Monserrato (Canada) (Italy); Chiriu, Daniele; Carbonaro, Carlo Maria; Corpino, Riccardo [Dipartimento di Fisica, Università degli Studi di Cagliari, Complesso universitario di Monserrato, SS 554, bivio per Sestu, Monserrato (Canada) (Italy); Ricci, Pier Carlo, E-mail: carlo.ricci@dsf.unica.it [Dipartimento di Fisica, Universitá degli Studi di Cagliari, S.P. Monserrato-Sestu Km 0,700, 09042 Monserrato (Canada) (Italy)

2014-10-21

It is well known that stilbene with a trans conformation is highly fluorescent. From the viewpoint of molecular structure, coumarins bear a carbon-carbon double bond which is fixed as trans conformation as in trans-stilbene through a lactone structure. This can help to avoid the trans-cis transformation of the double bond under ultraviolet (UV) irradiation as observed in stilbene compounds and results in strong fluorescence and high fluorescence quantum yield and photostability in most of coumarin derivatives. Herein we report some preliminary results about the synthesis and spectroscopic characterization of tunable coumarins and the development of a new linkage protocol for the obtainment of monolayer coumarin-covalently linked glasses. The resulting organic/inorganic coumarin/silica based Self-Assembled Monolayer (SMA) film is proposed as new phosphors for the substituting of critical raw materials, like rare earths, in photonics applications.

Synthesis and corrosion protection properties of poly(o-phenylenediamine nanofibers

Directory of Open Access Journals (Sweden)

P. Muthirulan

2013-07-01

Full Text Available The present study shows a novel method for the synthesis of uniformly-shaped poly(othophenylediamine (PoPD nanofibers by chemical oxidative polymerization method for application towards smart corrosion resistance coatings. Transmission Electron Microscopy (TEM and Scanning Electron Microscopy (SEM studies confirm morphology of PoPD with three dimensional (3D networked dendritic superstructures having average diameter of 50–70 nm and several hundred meters of length. UV–vis and FTIR spectral results shows the formation of PoPD nanofibers containing phenazine ring ladder-structure with benzenoid and quinoid imine units. Thermogravimetric analyses (TGA of PoPD nanofibers possess good thermal stability. The anti-corrosion behavior of PoPD nanofibers on 316L SS was investigated in 3.5% NaCl solution using potentiodynamic polarization and electrochemical impedance spectroscopic (EIS measurements. The PoPD coated 316L SS exhibits higher corrosion potential when compared to uncoated specimen. EIS studies, clearly ascertain that PoPD nanofiber coatings exhibits excellent potential barrier to protect the 316L SS against corrosion in 3.5% NaCl.

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

Science.gov (United States)

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

On estimating the background of remote sensing gamma-ray spectroscopic data

Energy Technology Data Exchange (ETDEWEB)

Zhu, Meng-Hua, E-mail: mhzhu@must.edu.mo

2016-10-01

In this paper, we considered the inverse count accumulation process of gamma-ray spectrum and derived an iterative filtering method to estimate the background of noisy spectroscopic data for the remote sensing observations of planetary surface. Compared with the SNIP method, the proposed method avoids the calculation of the average FWHM of the whole spectrum or the peak regions, which is an important parameter for the SNIP method. The synthetic and experimental spectra are used to validate the derived method. The results show that the proposed method can estimate the background efficiently, especially for the spectroscopic data with Compton continuum. In addition, by combining the proposed method and the SNIP method, the average FWHM can be determined easily, which can be used to validate the characteristics of detector.

Spectroscopic AC susceptibility imaging (sASI) of magnetic nanoparticles

International Nuclear Information System (INIS)

Ficko, Bradley W.; Nadar, Priyanka M.; Diamond, Solomon G.

2015-01-01

This study demonstrates a method for alternating current (AC) susceptibility imaging (ASI) of magnetic nanoparticles (mNPs) using low cost instrumentation. The ASI method uses AC magnetic susceptibility measurements to create tomographic images using an array of drive coils, compensation coils and fluxgate magnetometers. Using a spectroscopic approach in conjunction with ASI, a series of tomographic images can be created for each frequency measurement set and is termed sASI. The advantage of sASI is that mNPs can be simultaneously characterized and imaged in a biological medium. System calibration was performed by fitting the in-phase and out-of-phase susceptibility measurements of an mNP sample with a hydrodynamic diameter of 100 nm to a Brownian relaxation model (R 2 =0.96). Samples of mNPs with core diameters of 10 and 40 nm and a sample of 100 nm hydrodynamic diameter were prepared in 0.5 ml tubes. Three mNP samples were arranged in a randomized array and then scanned using sASI with six frequencies between 425 and 925 Hz. The sASI scans showed the location and quantity of the mNP samples (R 2 =0.97). Biological compatibility of the sASI method was demonstrated by scanning mNPs that were injected into a pork sausage. The mNP response in the biological medium was found to correlate with a calibration sample (R 2 =0.97, p<0.001). These results demonstrate the concept of ASI and advantages of sASI. - Highlights: • Development of an AC susceptibility imaging model. • Comparison of AC susceptibility imaging (ASI) and susceptibility magnitude imaging (SMI). • Demonstration of ASI and spectroscopic ASI (sASI) using three different magnetic nanoparticle types. • SASI scan separation of three different magnetic nanoparticles samples using 5 spectroscopic frequencies. • Demonstration of biological feasibility of sASI

Spectroscopic system for impurity measurements in the TJ-1 Tokamak of JEN

International Nuclear Information System (INIS)

Navas, G.; Zurro, B.

1982-01-01

we describe a spectroscopic system with spatial resolution capability that has been configured for plasma diagnostic in the TJ-1 Tokamak of JEN. The experimental system, based on a one meter monochromator, has been absolutely calibrated using a tungsten-halogen lamp. The calibration procedures and the absolute spectral sensitivity are presented as well as its dependence with the polarization. A simplified spectroscopic model of the radiation emitted by the intrinsic plasma impurities (C, 0, . . . ) has been developed. A one dimensional model of the temporal evolution of various ionization stages in coronal equilibrium is used to predict the electron temperature and impurity concentration. This model has been applied to experimental data from several Tokamaks. (Author) 23 refs

Nuclear data for geophysical spectroscopic logging

International Nuclear Information System (INIS)

Schweitzer, J.S.; Hertzog, R.C.; Soran, P.D.

1987-01-01

Nuclear geochemical analysis requires the quantitative measurement of elemental concentrations of trace elements, as well as major elements in widely varying concentrations. This requirement places extreme demands on the quality of the spectroscopic measurements, data rates, and relating observed γ-ray intensities to the original elemental concentration. The relationship between γ-ray intensities and elemental concentration is critically dependent on the specific reaction cross sections and their uncertainties. The elements of highest priority for subsurface geochemical analysis are considered with respect to the importance of competing reactions and the neutron energy regions that are most significant. (author)

Optical properties of metals by spectroscopic ellipsometry

International Nuclear Information System (INIS)

Arakawa, E.T.; Inagaki, T.; Williams, M.W.

1979-01-01

The use of spectroscopic ellipsometry for the accurate determination of the optical properties of liquid and solid metals is discussed and illustrated with previously published data for Li and Na. New data on liquid Sn and Hg from 0.6 to 3.7 eV are presented. Liquid Sn is Drude-like. The optical properties of Hg deviate from the Drude expressions, but simultaneous measurements of reflectance and ellipsometric parameters yield consistent results with no evidence for vectorial surface effects

Water soluble peripheral and non-peripheral tetrasubstituted zinc phthalocyanines: Synthesis, photochemistry and bovine serum albumin binding behavior

Energy Technology Data Exchange (ETDEWEB)

Çakır, Volkan; Çakır, Dilek [Department of Chemistry, Faculty of Sciences, Karadeniz Technical University, 61080 Trabzon (Turkey); Pişkin, Mehmet [Department of Food Technology, Çanakkale Vocational School of Technical Sciences, Çanakkale Onsekiz Mart University, 17100 Çanakkale (Turkey); Durmuş, Mahmut [Gebze Institute of Technology, Department of Chemistry, PO Box 141, Gebze 41400, Kocaeli (Turkey); Bıyıklıoğlu, Zekeriya, E-mail: zekeriya_61@yahoo.com [Department of Chemistry, Faculty of Sciences, Karadeniz Technical University, 61080 Trabzon (Turkey)

2014-10-15

The new peripherally and non-peripherally tetra-1,3-bis[3-(diethylamino)phenoxy]propan-2-ol substituted zinc(II) phthalocyanine complexes (2a and 3a) and their quaternized amphiphilic derivatives (2b and 3b) have been synthesized and characterized using UV–vis, FT-IR, {sup 1}H-NMR, {sup 13}C-NMR, MS spectroscopic data and elemental analysis for the first time. The quaternized complexes (2b and 3b) show excellent solubility in water and DMSO which makes them potential photosensitizers for use in photodynamic therapy (PDT) of cancer. The photochemical (singlet oxygen generation and photodegradation under light irradiation) properties of these novel phthalocyanines are investigated in dimethylsulfoxide (DMSO) for non-quaternized complexes and in DMSO, phosphate buffered solution (PBS) or PBS+triton X-100 (TX) solution for quaternized complexes. In this study, the effects of the aggregation of the molecules, quaternization, position of the substituents (peripherally or non-peripherally) and nature of the solvents (DMSO, PBS or PBS+triton X-100) on the photochemical parameters of the zinc (II) phthalocyanines are also reported. In addition, a spectroscopic investigation of the binding behavior of the quaternized zinc(II) phthalocyanine complexes to bovine serum albumin (BSA) is also presented in this work. - Highlights: • Synthesis of zinc phthalocyanines is performed. • Photophysical and photochemical properties of phthalocyanines are studied. • Photodynamic therapy studies are performed.

Water soluble peripheral and non-peripheral tetrasubstituted zinc phthalocyanines: Synthesis, photochemistry and bovine serum albumin binding behavior

International Nuclear Information System (INIS)

Çakır, Volkan; Çakır, Dilek; Pişkin, Mehmet; Durmuş, Mahmut; Bıyıklıoğlu, Zekeriya

2014-01-01

The new peripherally and non-peripherally tetra-1,3-bis[3-(diethylamino)phenoxy]propan-2-ol substituted zinc(II) phthalocyanine complexes (2a and 3a) and their quaternized amphiphilic derivatives (2b and 3b) have been synthesized and characterized using UV–vis, FT-IR, 1 H-NMR, 13 C-NMR, MS spectroscopic data and elemental analysis for the first time. The quaternized complexes (2b and 3b) show excellent solubility in water and DMSO which makes them potential photosensitizers for use in photodynamic therapy (PDT) of cancer. The photochemical (singlet oxygen generation and photodegradation under light irradiation) properties of these novel phthalocyanines are investigated in dimethylsulfoxide (DMSO) for non-quaternized complexes and in DMSO, phosphate buffered solution (PBS) or PBS+triton X-100 (TX) solution for quaternized complexes. In this study, the effects of the aggregation of the molecules, quaternization, position of the substituents (peripherally or non-peripherally) and nature of the solvents (DMSO, PBS or PBS+triton X-100) on the photochemical parameters of the zinc (II) phthalocyanines are also reported. In addition, a spectroscopic investigation of the binding behavior of the quaternized zinc(II) phthalocyanine complexes to bovine serum albumin (BSA) is also presented in this work. - Highlights: • Synthesis of zinc phthalocyanines is performed. • Photophysical and photochemical properties of phthalocyanines are studied. • Photodynamic therapy studies are performed

Thirty New Low-mass Spectroscopic Binaries

Science.gov (United States)

Shkolnik, Evgenya L.; Hebb, Leslie; Liu, Michael C.; Reid, I. Neill; Collier Cameron, Andrew

2010-06-01

As part of our search for young M dwarfs within 25 pc, we acquired high-resolution spectra of 185 low-mass stars compiled by the NStars project that have strong X-ray emission. By cross-correlating these spectra with radial velocity standard stars, we are sensitive to finding multi-lined spectroscopic binaries. We find a low-mass spectroscopic binary fraction of 16% consisting of 27 SB2s, 2 SB3s, and 1 SB4, increasing the number of known low-mass spectroscopic binaries (SBs) by 50% and proving that strong X-ray emission is an extremely efficient way to find M-dwarf SBs. WASP photometry of 23 of these systems revealed two low-mass eclipsing binaries (EBs), bringing the count of known M-dwarf EBs to 15. BD-22 5866, the ESB4, was fully described in 2008 by Shkolnik et al. and CCDM J04404+3127 B consists of two mid-M stars orbiting each other every 2.048 days. WASP also provided rotation periods for 12 systems, and in the cases where the synchronization time scales are short, we used P rot to determine the true orbital parameters. For those with no P rot, we used differential radial velocities to set upper limits on orbital periods and semimajor axes. More than half of our sample has near-equal-mass components (q > 0.8). This is expected since our sample is biased toward tight orbits where saturated X-ray emission is due to tidal spin-up rather than stellar youth. Increasing the samples of M-dwarf SBs and EBs is extremely valuable in setting constraints on current theories of stellar multiplicity and evolution scenarios for low-mass multiple systems. Based on observations collected at the W. M. Keck Observatory, the Canada-France-Hawaii Telescope and by the WASP Consortium. The Keck Observatory is operated as a scientific partnership between the California Institute of Technology, the University of California, and NASA, and was made possible by the generous financial support of the W. M. Keck Foundation. The CFHT is operated by the National Research Council of Canada

Raman spectroscopic studies on CeVO4 at high pressures

International Nuclear Information System (INIS)

Rao, Rekha; Garg, Alka B.; Wani, B.N.

2011-01-01

Raman scattering investigations of CeVO 4 at high pressures is reported. Polycrystalline CeVO 4 was prepared by solid state reaction of CeO 2 and V 2 O 5 . High pressure Raman spectroscopic measurements were carried out as per experimental details given

2.2.1. Synthesis, spectroscopic characterization and crystal structure of [ReV(O2(pyz4][ReII(NOBr4(pyz] (pyz = pyrazine

Directory of Open Access Journals (Sweden)

Mario Pacheco, Alicia Cuevas, Javier González-Platas, Carlos Kremer*

2015-03-01

Full Text Available Abstract: A novel Re(V-Re(II nitrosyl complex, [Re(O2(pyz 4][Re(NOBr4(pyz] (pyz = pyrazine was prepared and characterized by X-ray diffraction, elemental analysis, infrared and ultraviolet-visible absorption spectra. This product is obtained in the initial steps of the reaction of (NBu4[Re(NOBr4(EtOH] with pyrazine. Both, the cation and the anion are mononuclear complexes. The Re(V atom in the cation is six-coordinate with four nitrogen atoms from pyrazine ligands, and two oxo ligands. The Re(II anion is also six-coordinate, with four bromide ligands, a linear nitrosyl group and one nitrogen from pyrazine. The spectroscopic studies are discussed and compared with those already reported separately for the cation and the anion. Supporting information: X-Ray (CIF file

Synthesis, spectroscopic and catalytic properties of some new boron hybrid molecule derivatives by BF2 and BPh2 chelation

Science.gov (United States)

Kilic, Ahmet; Alcay, Ferhat; Aydemir, Murat; Durgun, Mustafa; Keles, Armagan; Baysal, Akın

2015-05-01

A new series of Schiff base ligands (L1-L3) and their corresponding fluorine/phenyl boron hybrid complexes [LnBF2] and [LnBPh2] (n = 1, 2 or 3) have been synthesized and well characterized by both analytical and spectroscopic methods. The Schiff base ligands and their corresponding fluorine/phenyl boron hybrid complexes have been characterized by NMR (1H, 13C and 19F), FT-IR, UV-Vis, LC-MS, and fluorescence spectroscopy as well as melting point and elemental analysis. The fluorescence efficiencies of phenyl chelate complexes are greatly red-shifted compared to those of the fluorine chelate analogs based on the same ligands, presumably due to the large steric hindrance and hard π → π∗ transition of the diphenyl boron chelation, which can effectively prevent molecular aggregation. The boron hybrid complexes were applied to the transfer hydrogenation of acetophenone derivatives to 1-phenylethanol derivatives in the presence of 2-propanol as the hydrogen source. The catalytic studies showed that boron hybrid complexes are good catalytic precursors for transfer hydrogenation of aromatic ketones in 0.1 M iso-PrOH solution. Also, we have found that both steric and electronic factors have a significant impact on the catalytic properties of this class of molecules.

New synthesis parameters of GGG:Nd nanocrystalline powder prepared by sol–gel method: Structural and spectroscopic investigation

Energy Technology Data Exchange (ETDEWEB)

Alshikh Mohamad, Yassin, E-mail: yassinm@mail.ru; Atassi, Yomen; Moussa, Zafer

2015-09-15

GGG:Nd nanopowder is synthesized by the sol–gel method using formic acid and acetic acid as chelating agents and ethylene glycol as a cross linking agent. TGA–DSC, XRD, photoluminescence spectroscopy and fluorescence life time analysis (τ) are used to characterize the powder. XRD is used to optimize the synthesis parameters. According to XRD, complete phase of GGG nanopowder is formed at 800 °C for 1 min. Fluorescence life time analyses reveal that the optimum crystallization temperature is 1000 °C. - Highlights: • GGG:Nd nanopowder was prepared using formic acid by the sol gel method. • Optimization of sol gel parameters was done. • GGG phase formation was complete at 800 °C for 1 min • According to τ measurements, optimal temperature treatment is at 1000 °C. • Nanopowder prepared with formic acid was better than that formed with acetic acid.

APPLYING SPECTROSCOPIC METHODS ON ANALYSES OF HAZARDOUS WASTE

OpenAIRE

Dobrinić, Julijan; Kunić, Marija; Ciganj, Zlatko

2000-01-01

Abstract The paper presents results of measuring the content of heavy and other metals in waste samples from the hazardous waste disposal site of Sovjak near Rijeka. The preliminary design elaboration and the choice of the waste disposal sanification technology were preceded by the sampling and physico-chemical analyses of disposed waste, enabling its categorization. The following spectroscopic methods were applied on metal content analysis: Atomic absorption spectroscopy (AAS) and plas...

Electronic properties of diphenyl-s-tetrazine and some related oligomers. An spectroscopic and theoretical study

Energy Technology Data Exchange (ETDEWEB)

Moral, Monica; Garcia, Gregorio [Departamento de Quimica Fisica y Analitica, Facultad de Ciencias Experimentales, Universidad de Jaen, Campus las Lagunillas, E23071 Jaen (Spain); Penas, Antonio [Departamento de Quimica Inorganica y Organica, Facultad de Ciencias Experimentales, Universidad de Jaen, Campus las Lagunillas, E23071 Jaen (Spain); Garzon, Andres; Granadino-Roldan, Jose M. [Departamento de Quimica Fisica y Analitica, Facultad de Ciencias Experimentales, Universidad de Jaen, Campus las Lagunillas, E23071 Jaen (Spain); Melguizo, Manuel [Departamento de Quimica Inorganica y Organica, Facultad de Ciencias Experimentales, Universidad de Jaen, Campus las Lagunillas, E23071 Jaen (Spain); Fernandez-Gomez, Manuel, E-mail: mfg@ujaen.es [Departamento de Quimica Fisica y Analitica, Facultad de Ciencias Experimentales, Universidad de Jaen, Campus las Lagunillas, E23071 Jaen (Spain)

2012-10-26

Highlights: Black-Right-Pointing-Pointer We study properties of Ph{sub 2}Tz and (PhTz){sub n}Ph as candidates for organic electronics. Black-Right-Pointing-Pointer The synthesis of Ph{sub 2}Tz was performed through a modified Pinner-type reaction. Black-Right-Pointing-Pointer IR/Raman spectra allowed to conclude that Ph{sub 2}Tz is nearly planar in liquid phase. Black-Right-Pointing-Pointer Electronic structure was studied by UV-Vis/TD-DFT methods in different solvents. Black-Right-Pointing-Pointer Bandgap, E{sub LUMO}, electron mobility predict some n-type character for limit polymer. -- Abstract: This work presents a theoretical and spectroscopic study on the electronic and structural properties of the diphenyl-s-tetrazine molecule (Ph{sub 2}Tz) and some oligomeric derivatives. Ph{sub 2}Tz was synthesized through a variation of Pinner-type reaction which uses N-acetylcysteine as catalyst. Insight into the structure and electronic properties of the title compound was obtained through IR, Raman, UV-Vis spectra in different solvents, and theoretical calculations. Theoretical studies have been extended to different n-mers derivatives up to an ideal molecular wire through the oligomeric approximation, predicting this way electronic properties such as LUMO energy levels, electron affinity and reorganization energy in order to assess their possible applications in molecular electronics.

A comparison of Hipparcos parallaxes with planetary nebulae spectroscopic distances

NARCIS (Netherlands)

Pottasch, [No Value; Acker, A

1998-01-01

The Hipparcos satellite has measured the parallax of a small sample of planetary nebulae. In this paper we consider the results for 3 planetary nebulae (PN) for which spectroscopic distances have also been determined from stellar gravities. These gravities in turn have been derived from profile

Characterization of ion-implanted aluminum and iron by spectroscopic ellipsometry

International Nuclear Information System (INIS)

Brodkin, J.S.; Franzen, W.; Culbertson, R.J.

1990-01-01

The change in the optical constants of aluminum alloy and iron samples caused by implantation with nitrogen and chromium ions has been investigated by spectroscopic ellipsometry. The objective is to develop a method for simple, non-destructive characterization of ion-implanted metals. 5 refs., 6 figs

On-line data processing apparatus for spectroscopic measurements of atomic uranium

International Nuclear Information System (INIS)

Miron, E.; Levin, L.A.; Erez, G; Baumatz, D; Goren, I.; Shpancer, I.

1977-01-01

A computer-based apparatus for on-line spectroscopic measurements of atomic uranium is described. The system is capable of enhancing the signal-to-noise ratio by averaging, and performing calculations. Computation flow charts and programs are included

Charged particle reaction studies on /sup 14/C. [Spectroscopic factors

Energy Technology Data Exchange (ETDEWEB)

Cecil, F E; Shepard, J R; Anderson, R E; Peterson, R J; Kaczkowski, P [Colorado Univ., Boulder (USA). Nuclear Physics Lab.

1975-12-22

The reactions /sup 14/C(p,d), (d,d') and (d,p) have been measured for E/sub p/ = 27 MeV and E/sub d/ = 17 MeV. The (d,d') and (d,p) reactions were studied between theta/sub lab/ = 15/sup 0/ and 85/sup 0/; the (p,d) reactions, between theta/sub lab/ = 5/sup 0/ and 40/sup 0/. The /sup 14/C deformation parameters were deduced from the deuteron inelastic scattering and found to agree with deformations measured in nearby doubly even nuclei. The spectroscopic factors deduced from the (p,d) reaction allowed a /sup 14/C ground-state wave function to be deduced which compares favorably with a theoretically deduced wave function. The (p,d) and (d,p) spectroscopic factors are consistent. The implications of our /sup 14/C ground-state wave function regarding the problem of the /sup 14/C hindered beta decay are discussed.

Automated processing for proton spectroscopic imaging using water reference deconvolution.

Science.gov (United States)

Maudsley, A A; Wu, Z; Meyerhoff, D J; Weiner, M W

1994-06-01

Automated formation of MR spectroscopic images (MRSI) is necessary before routine application of these methods is possible for in vivo studies; however, this task is complicated by the presence of spatially dependent instrumental distortions and the complex nature of the MR spectrum. A data processing method is presented for completely automated formation of in vivo proton spectroscopic images, and applied for analysis of human brain metabolites. This procedure uses the water reference deconvolution method (G. A. Morris, J. Magn. Reson. 80, 547(1988)) to correct for line shape distortions caused by instrumental and sample characteristics, followed by parametric spectral analysis. Results for automated image formation were found to compare favorably with operator dependent spectral integration methods. While the water reference deconvolution processing was found to provide good correction of spatially dependent resonance frequency shifts, it was found to be susceptible to errors for correction of line shape distortions. These occur due to differences between the water reference and the metabolite distributions.

Time-Resolved Emission Spectroscopic Study of Laser-Induced Steel Plasmas

International Nuclear Information System (INIS)

Shah, M. L.; Pulhani, A. K.; Suri, B. M.; Gupta, G. P.

2013-01-01

Laser-induced steel plasma is generated by focusing a Q-switched Nd:YAG visible laser (532 nm wavelength) with an irradiance of ∼ 1 × 10 9 W/cm 2 on a steel sample in air at atmospheric pressure. An Echelle spectrograph coupled with a gateable intensified charge-coupled detector is used to record the plasma emissions. Using time-resolved spectroscopic measurements of the plasma emissions, the temperature and electron number density of the steel plasma are determined for many times of the detector delay. The validity of the assumption by the spectroscopic methods that the laser-induced plasma (LIP) is optically thin and is also in local thermodynamic equilibrium (LTE) has been evaluated for many delay times. From the temporal evolution of the intensity ratio of two Fe I lines and matching it with its theoretical value, the delay times where the plasma is optically thin and is also in LTE are found to be 800 ns, 900 ns and 1000 ns.

Specific binding of a dihydropyrimidinone derivative with DNA: Spectroscopic, calorimetric and modeling investigations

International Nuclear Information System (INIS)

Wang Gongke; Yan Changling; Wang Dongchao; Li Dan; Lu Yan

2012-01-01

One of the dihydropyrimidinone derivative 5-(ethoxycarbonyl)-6-methyl-4-(4-methoxyphenyl) -3,4-dihydropyrimidin-2(1H)-one (EMMD) was synthesized, and its binding properties with calf-thymus DNA (ctDNA) were investigated using spectroscopic, viscometric, isothermal titration calorimetric (ITC) and molecular modeling techniques. Fluorescence spectra suggested that the fluorescence enhancement of the binding interaction of EMMD to ctDNA was a static process with ground state complex formation. The binding constant determined with spectroscopic titration and ITC was found to be in the same order of 10 4 M −1 . According to the results of the viscosity analysis, fluorescence competitive binding experiment, fluorescence quenching studies, absorption spectral and ITC investigations, it can be concluded that EMMD is intercalative binding to ctDNA. Furthermore, the results of molecular modeling confirmed those obtained from spectroscopic, viscosimetric and ITC investigations. Additionally, ITC studies also indicated that the binding interaction is predominantly enthalpy driven. - Highlights: ► Medically important dihydropyrimidinones derivative EMMD is synthesized. ► EMMD is intercalative binding into ctDNA helix. ► Hydrogen bonding may play an essential role in the binding of EMCD with ctDNA. ► This binding interaction is predominantly enthalpy driven.

Synthesis and Low Temperature Spectroscopic Observation of 1,3,5-Trioxane-2,4,6-Trione: The Cyclic Trimer of Carbon Dioxide

Science.gov (United States)

2016-08-19

Dewar flask with a viewing window feature. A 5% O3/O2 mixture from the ozone generator (10 V coronal discharge ) was delivered to the cold solution...orthocarbonate extended covalent structure of interconnected six-membered rings was predicted by model calculation with the finding of a stabilization energy...stability. The approach is that of a model compound synthesis where the trioxane ring is first generated from substituted aldehydes and then the

Synthesis of highly stable silver nanoparticles through a novel green method using Mirabillis jalapa for antibacterial, nonlinear optical applications

Science.gov (United States)

Pugazhendhi, S.; Palanisamy, P. K.; Jayavel, R.

2018-05-01

Green synthesis techniques are developing as more simplistic and eco-friendly approach for the synthesis of metal nanoparticles compared to chemical reduction methods. Herein we report Synthesis of highly stable silver nanoparticles using Mirabillis jalapa seed extract as a reducing and capping agent. The as-prepared silver nanoparticles were characterized by UV-vis spectroscopy (UV-vis) to confirm the formation of silver nanoparticles by its characteristic surface plasmon resonance peak observed at 420 nm. The Powder X-ray diffraction (P-XRD) revealed the structure and crystalline nature of synthesized silver nanoparticles, The Fourier transform infra-red spectroscopic (FT-IR) revealed the presence of the biomolecules in the extract that acted as reducing as well stabilizing agent. The high resolution transmission electron microscopic (HRTEM) images divulged that the synthesized silver nanoparticles were spherical in shape and poly dispersed. The energy dispersive X-ray diffraction (EDX) profile revealed the elements present in the as-synthesized colloidal silver nanoparticles and its percentages. The Zeta potential measured for silver nanoparticles evidenced that the prepared silver nanoparticles owned high stability in room temperature itself. The as-synthesized silver nanoparticles (AgNPs) in colloidal form were showed good antimicrobial effects and it's were found to exhibit third order optical nonlinearity as studied by Z-scan technique using 532 nm Nd:YAG (SHG) CW laser beam (COHERENT-Compass 215 M-50 diode pumped) output as source. The negative nonlinearity observed was well utilized for the study of optical limiting behavior of the silver nanoparticles.

SDSS-IV MaNGA: the spectroscopic discovery of strongly lensed galaxies

Science.gov (United States)

Talbot, Michael S.; Brownstein, Joel R.; Bolton, Adam S.; Bundy, Kevin; Andrews, Brett H.; Cherinka, Brian; Collett, Thomas E.; More, Anupreeta; More, Surhud; Sonnenfeld, Alessandro; Vegetti, Simona; Wake, David A.; Weijmans, Anne-Marie; Westfall, Kyle B.

2018-06-01

We present a catalogue of 38 spectroscopically detected strong galaxy-galaxy gravitational lens candidates identified in the Sloan Digital Sky Survey IV (SDSS-IV). We were able to simulate narrow-band images for eight of them demonstrating evidence of multiple images. Two of our systems are compound lens candidates, each with two background source-planes. One of these compound systems shows clear lensing features in the narrow-band image. Our sample is based on 2812 galaxies observed by the Mapping Nearby Galaxies at APO (MaNGA) integral field unit (IFU). This Spectroscopic Identification of Lensing Objects (SILO) survey extends the methodology of the Sloan Lens ACS Survey (SLACS) and BOSS Emission-Line Survey (BELLS) to lower redshift and multiple IFU spectra. We searched ˜1.5 million spectra, of which 3065 contained multiple high signal-to-noise ratio background emission-lines or a resolved [O II] doublet, that are included in this catalogue. Upon manual inspection, we discovered regions with multiple spectra containing background emission-lines at the same redshift, providing evidence of a common source-plane geometry which was not possible in previous SLACS and BELLS discovery programs. We estimate more than half of our candidates have an Einstein radius ≳ 1.7 arcsec, which is significantly greater than seen in SLACS and BELLS. These larger Einstein radii produce more extended images of the background galaxy increasing the probability that a background emission-line will enter one of the IFU spectroscopic fibres, making detection more likely.

Facility at CIRUS reactor for thermal neutron induced prompt γ-ray spectroscopic studies

International Nuclear Information System (INIS)

Biswas, D.C.; Danu, L.S.; Mukhopadhyay, S.; Kinage, L.A.; Prashanth, P.N.; Goswami, A.; Sahu, A.K.; Shaikh, A.M.; Chatterjee, A.; Choudhury, R.K.; Kailas, S.

2013-01-01

A facility for prompt γ-ray spectroscopic studies using thermal neutrons from a radial beam line of Canada India Research Utility Services (CIRUS) reactor, Bhabha Atomic Research Centre (BARC), has been developed. To carry out on-line spectroscopy experiments, two clover germanium detectors were used for the measurement of prompt γ rays. For the first time, the prompt γ–γ coincidence technique has been used to study the thermal neutron induced fission fragment spectroscopy (FFS) in 235 U(n th , f). Using this facility, experiments have also been carried out for on-line γ-ray spectroscopic studies in 113 Cd(n th , γ) reaction

Investigation and measures to noise on spectroscopic measurement system in JT-60U

International Nuclear Information System (INIS)

Nagaya, Susumu; Kubo, Hirotaka; Sugie, Tatsuo; Onizawa, Masami; Kawai, Isao; Nakata, Hisao.

1997-11-01

Breakdown of a negative-ion-based neutral beam injection (N-NBI) has caused noise trouble to several systems. The control circuit of a spectroscopic measurement system had not well worked because of the noise. The noise has been measured by an optical-fiber isolation system during operation of JT-60U. The amplitude and the frequency were 15-18 V and 15 MHz respectively. The transmission noise has been reduced by putting ferrite cores to all cables connecting with the control circuits. As a result, the trouble with the spectroscopic measurement system has completely been solved. Adding condensers and resistors to the circuit was not effective to reduce the noise. (author)

Electrochemical synthesis and spectroscopic characterization of ...

African Journals Online (AJOL)

phenylpyrrole) coatings in an organic medium on iron and platinum electrodes. ... XPS measurements, infrared (FT-IR) and electronic absorption (UV-vis) spectroscopies were used to characterize the iron and platinum-coated electrodes. Finally the ...

Synthesis, molecular structure, spectroscopic investigations and ...

Indian Academy of Sciences (India)

MS received 29 December 2015; revised 9 April 2016; accepted 25 May 2016 ... B, open form blue. Scheme 1. Structures and Photochromic reaction of the title compound. 2. Experimental. 2.1 Materials and measurements. The mid-IR spectra were obtained in the ... segment is put between two parallel Au(111) surfaces,.

Synthesis, spectroscopic, electrochemical and luminescence studies ...

Indian Academy of Sciences (India)

Unknown

Ruthenium (II) 2,2′-bipyridyl and 1,10-phenanthroline complexes with 4- ... with hydrazine to form its N2 complex which is of great interest in the chemistry of N2 ... part of this ligand could be converted into N2 also enthused us to take up the ...

Synthesis, spectroscopic characterization and catalytic oxidation ...

Indian Academy of Sciences (India)

were characterized by infrared, electronic, electron paramagnetic resonance ... The catalytic oxidation property of ruthenium(III) complexes were also ... cies at room temperature. ..... aldehyde part of Schiff base ligands, catalytic activ- ity of new ...

Ionic Liquid-assisted Synthesis of Cellulose/TiO2 Composite and Photocatalytic Performance

Directory of Open Access Journals (Sweden)

ZHU Mo-shuqi

2016-12-01

Full Text Available Cellulose/TiO2 composite was prepared by sol-gel method using the ionic liquid BMIMCl as reactive medium and Ti(OBu4 as a precursor. The synthesis conditions were optimized by single-factor experiment. The structure and properties of the composite were characterized by scanning electron microscope (SEM,X-ray diffraction(XRD,Fourier transform infrared spectoscopy(FT-IR,UV-vis-diffuse reflectance spectroscope(DRS and thermogravimetric (TG analysis. The photocatalytic activity of the composite was investigated via testing the photodegradation of methyl orange in aqueous suspension under UV-light. The results show that the high active photocatalytic composite is prepared by using ionic liquid BMIMCl as medium at room temperature and atmospheric pressure. The photo catalytic degradation rate of composite on methyl orange(MO reaches 97.09% in 80min. Comparing with bare TiO2, the degradation rate of MO increases by 37%. Moreover, the composite still shows 62.66% degradation rate towards MO after recycling 4 times.

Synthesis and antileishmanial activity of antimony (V) complexes of hydroxypyranone and hydroxypyridinone ligands.

Science.gov (United States)

Sheikhmoradi, Vafa; Saberi, Sedigheh; Saghaei, Lotfollah; Pestehchian, Nader; Fassihi, Afshin

2018-04-01

A novel series of antimony (V) complexes with the hydroxypyranone and hydroxypyridinone ligands were synthesized and characterized by 1 HNMR, FT-IR and electron spin ionization mass spectroscopic (ESI-MS) techniques. The synthesis process involved protection of hydroxyl group followed by the reaction of the intermediate with primary amines and finally deprotection. All compounds were evaluated for in vitro activities against the amastigote and promastigote forms of Leishmania major . Most of the synthesized compounds exhibited good antileishmanial activity against both forms of L. major . IC 50 values of the most active compounds; 9d , 9d and 9e , after 24, 48 and 72 h against amastigote model were 15, 12.5 and 5.5 μg/mL, respectively. 9e , 11 and 9e inhibited the promastigote form of parasite after 24, 48 and 72 h with IC 50 values of 10, 2 and 1 μg/mL, respectively.

Chromium(III) Complex Obtained from Dipicolinic Acid: Synthesis, Characterization, X-Ray Crystal Structure and Electrochemical Studies

Energy Technology Data Exchange (ETDEWEB)

Ghasemi, Khaled; Rezvani, Ali Reza; Ghasemi, Fatemeh [Univ. of Sistan and Baluchestan, Zahedan (Iran, Islamic Republic of); Razak, Ibrahim Abdul; Rosli, Mohd Mustaqim [Universiti Sains Malaysia, Penang (Malaysia)

2013-10-15

The synthesis, X-ray crystallography, spectroscopic (IR, UV-vis), and electrochemical properties of the title compound, [H{sub 3}O][Cr(dipic){sub 2}] [H{sub 3}O{sup +}.Cl{sup -}] (1), (H{sub 2}dipic = 2,6-pyridinedicarboxylic acid), are reported. This complex crystallizes in the monoclinic space group Cc with a = 14.9006(10) A, b = 12.2114(8) A, c = 8.6337(6) A, α = 90.00 .deg., β = 92.7460(10) .deg., γ = 90.00 .deg., and V = 1569.16(18) A3 with Z = 4. The hydrogen bonding and noncovalent interactions play roles in the stabilization of the structure. In order to gain a better understanding of the most important geometrical parameters in the structure of the complex, atoms in molecules (AIM) method at B3LYP/6-31G level of theory has been employed.

PG 1605+072 in Wet XCov22: Support for the Multi Site Spectroscopic Telescope

Directory of Open Access Journals (Sweden)

Schuh S. L.

2003-03-01

Full Text Available The Multi-site spectroscopic telescope is a virtual instrument and the name of a collaboration that opens up a new observational window by combining continuous observations of spectroscopic variations and simultaneous photometric monitoring. This constitutes an enormous observational effort, but in return promises to finally provide access to a mode identification for and an asteroseismological analysis of the pulsating sdB star PG 1605+072. Multi-Site Spectroscopic Telescope observations for this object have been secured during a large coordinated campaign in May and June of the year 2002. The frequency resolution and coverage of the photometric time series has been noticeably enhanced by a significant contribution from the Whole Earth Telescope, which was used to observe PG 1605+072 as an alternate target during the WET XCov22 campaign, also conducted in May 2002. This paper briefly outlines the motivation for the MSST project and tries to give a first assessment of the overall quality of the data obtained, with a focus on the Whole Earth Telescope observations.

Single hole spectroscopic strength in 98Ru through the 99Ru(d,t) reaction

International Nuclear Information System (INIS)

Rodrigues, M.R.D.; Borello-Lewin, T.; Horodynski-Matsushigue, L.B.; Duarte, J.L.M.; Rodrigues, C.L.; Barbosa, M.D.L.; Silva, G.B. da; Ukita, G.M.

2002-01-01

The 99 Ru(d,t) 98 Ru reaction was measured for the first time at 16 MeV incident energy with the Sao Paulo Pelletron-Enge-spectrograph facility employing the nuclear emulsion technique. In all, up to 3.5 MeV, 23 levels were detected, eight of them new; angular distributions are presented for all of them. Least squares fits of distorted wave Born approximation one-neutron pickup predictions to the rather well structured experimental angular distributions enabled the determination of l transfers and of the corresponding spectroscopic factors for 19 of these states, some being tentative attributions. Only transfers of l=0, 2, and 4 were observed. Several states were populated through single l transfers. A pure l=2 transfer is associated with the 2 1 + level and with several other states which are considered collective, as well as with the (4 + ) state at 2.277 MeV, which presents the highest spectroscopic strength. Considering five valence neutrons above the N=50 core, only 41% of the spectroscopic strength expected for 99 Ru was detected

Spectroscopic ellipsometry analysis of a thin film composite membrane consisting of polysulfone on a porous α-alumina support.

Science.gov (United States)

Ogieglo, Wojciech; Wormeester, Herbert; Wessling, Matthias; Benes, Nieck E

2012-02-01

Exposure of a thin polymer film to a fluid can affect properties of the film such as the density and thickness. In particular in membrane technology, these changes can have important implications for membrane performance. Spectroscopic ellipsometry is a convenient technique for in situ studies of thin films, because of its noninvasive character and very high precision. The applicability of spectroscopic ellipsometry is usually limited to samples with well-defined interfacial regions, whereas in typical composite membranes, often substantial and irregular intrusion of the thin film into the pores of a support exists. In this work, we provide a detailed characterization of a polished porous alumina membrane support, using variable-angle spectroscopic ellipsometry in combination with atomic force microscopy and mercury porosimetry. Two Spectroscopic ellipsometry optical models are presented that can adequately describe the surface roughness of the support. These models consider the surface roughness as a distinct layer in which the porosity gradually increases toward the outer ambient interface. The first model considers the porosity profile to be linear; the second model assumes an exponential profile. It is shown that the models can be extended to account for a composite membrane geometry, by deposition of a thin polysulfone film onto the support. The developed method facilitates practicability for in situ spectroscopic ellipsometry studies of nonequilibrium systems, i.e., membranes under actual permeation conditions.

THE SPECTROSCOPIC DIVERSITY OF TYPE Ia SUPERNOVAE

International Nuclear Information System (INIS)

Blondin, S.; Matheson, T.; Kirshner, R. P.; Mandel, K. S.; Challis, P.; Berlind, P.; Calkins, M.; Garnavich, P. M.; Jha, S. W.; Modjaz, M.; Riess, A. G.; Schmidt, B. P.

2012-01-01

We present 2603 spectra of 462 nearby Type Ia supernovae (SNe Ia), including 2065 previously unpublished spectra, obtained during 1993-2008 through the Center for Astrophysics Supernova Program. There are on average eight spectra for each of the 313 SNe Ia with at least two spectra. Most of the spectra were obtained with the FAST spectrograph at the Fred Lawrence Whipple Observatory 1.5 m telescope and reduced in a consistent manner, making this data set well suited for studies of SN Ia spectroscopic diversity. Using additional data from the literature, we study the spectroscopic and photometric properties of SNe Ia as a function of spectroscopic class using the classification schemes of Branch et al. and Wang et al. The width-luminosity relation appears to be steeper for SNe Ia with broader lines, although the result is not statistically significant with the present sample. Based on the evolution of the characteristic Si II λ6355 line, we propose improved methods for measuring velocity gradients, revealing a larger range than previously suspected, from ∼0 to ∼400 km s −1 day −1 considering the instantaneous velocity decline rate at maximum light. We find a weaker and less significant correlation between Si II velocity and intrinsic B – V color at maximum light than reported by Foley et al., owing to a more comprehensive treatment of uncertainties and host galaxy dust. We study the extent of nuclear burning and the presence of unburnt carbon in the outermost layers of the ejecta and report new detections of C II λ6580 in 23 early-time SN Ia spectra. The frequency of C II detections is not higher in SNe Ia with bluer colors or narrower light curves, in conflict with the recent results of Thomas et al. Based on nebular spectra of 27 SNe Ia, we find no relation between the FWHM of the iron emission feature at ∼4700 Å and Δm 15 (B) after removing the two low-luminosity SN 1986G and SN 1991bg, suggesting that the peak luminosity is not strongly dependent

Microwave-assisted ionothermal synthesis of nanostructured anatase titanium dioxide/activated carbon composite as electrode material for capacitive deionization

International Nuclear Information System (INIS)

Liu, Po-I; Chung, Li-Ching; Shao, Hsin; Liang, Teh-Ming; Horng, Ren-Yang; Ma, Chen-Chi M.; Chang, Min-Chao

2013-01-01

The nanostructured anatase titanium dioxide/activated carbon composite material for capacitive deionization electrode was prepared in a short time by a lower temperature two-step microwave-assisted ionothermal (sol–gel method in the presence of ionic liquid) synthesis method. This method includes a reaction and a crystallization step. In the crystallization step, the ionic liquid plays a hydrothermal analogy role in driving the surface anatase crystallization of amorphous titanium dioxide nanoparticles formed in the reaction step. The energy dispersive spectroscopic study of the composite indicates that the anatase titanium dioxide nanoparticles are evenly deposited in the matrix of activated carbon. The electrochemical property of the composite electrode was investigated. In comparison to the pristine activated carbon electrode, higher specific capacitance was observed for the nanostructured anatase titanium dioxide/activated carbon composite electrode, especially when the composite was prepared with a molar ratio of titanium tetraisopropoxide/H 2 O equal to 1:15. Its X-ray photoelectron spectroscopic result indicates that it has the highest amount of Ti-OH. The Ti-OH group can enhance the wetting ability and the specific capacitance of the composite electrode. The accompanying capacitive deionization result indicates that the decay of electrosorption capacity of this composite electrode is insignificant after five cycle tests. It means that the ion electrosorption–desorption becomes a reversible process

SINGLE-LINED SPECTROSCOPIC BINARY STAR CANDIDATES IN THE RAVE SURVEY

International Nuclear Information System (INIS)

Matijevic, G.; Zwitter, T.; Bienayme, O.; Siebert, A.; Watson, F. G.; Bland-Hawthorn, J.; Parker, Q. A.; Freeman, K. C.; Gilmore, G.; Grebel, E. K.; Helmi, A.; Munari, U.; Siviero, A.; Navarro, J. F.; Reid, W.; Seabroke, G. M.; Steinmetz, M.; Williams, M.; Wyse, R. F. G.

2011-01-01

Repeated spectroscopic observations of stars in the RAdial Velocity Experiment (RAVE) database are used to identify and examine single-lined binary (SB1) candidates. The RAVE latest internal database (VDR3) includes radial velocities, atmospheric parameters, and other parameters for approximately a quarter of a million different stars with slightly less than 300,000 observations. In the sample of ∼20,000 stars observed more than once, 1333 stars with variable radial velocities were identified. Most of them are believed to be SB1 candidates. The fraction of SB1 candidates among stars with several observations is between 10% and 15% which is the lower limit for binarity among RAVE stars. Due to the distribution of time spans between the re-observation that is biased toward relatively short timescales (days to weeks), the periods of the identified SB1 candidates are most likely in the same range. Because of the RAVE's narrow magnitude range most of the dwarf candidates belong to the thin Galactic disk while the giants are part of the thick disk with distances extending to up to a few kpc. The comparison of the list of SB1 candidates to the VSX catalog of variable stars yielded several pulsating variables among the giant population with radial velocity variations of up to few tens of km s -1 . There are 26 matches between the catalog of spectroscopic binary orbits (S B 9 ) and the whole RAVE sample for which the given periastron time and the time of RAVE observation were close enough to yield a reliable comparison. RAVE measurements of radial velocities of known spectroscopic binaries are consistent with their published radial velocity curves.

Self-assembled catalytic DNA nanostructures for synthesis of para-directed polyaniline.

Science.gov (United States)

Wang, Zhen-Gang; Zhan, Pengfei; Ding, Baoquan

2013-02-26

Templated synthesis has been considered as an efficient approach to produce polyaniline (PANI) nanostructures. The features of DNA molecules enable a DNA template to be an intriguing template for fabrication of emeraldine PANI. In this work, we assembled HRP-mimicking DNAzyme with different artificial DNA nanostructures, aiming to manipulate the molecular structures and morphologies of PANI nanostructures through the controlled DNA self-assembly. UV-vis absorption spectra were used to investigate the molecular structures of PANI and monitor kinetic growth of PANI. It was found that PANI was well-doped at neutral pH and the redox behaviors of the resultant PANI were dependent on the charge density of the template, which was controlled by the template configurations. CD spectra indicated that the PANI threaded tightly around the helical DNA backbone, resulting in the right handedness of PANI. These reveal the formation of the emeraldine form of PANI that was doped by the DNA. The morphologies of the resultant PANI were studied by AFM and SEM. It was concluded from the imaging and spectroscopic kinetic results that PANI grew preferably from the DNAzyme sites and then expanded over the template to form 1D PANI nanostructures. The strategy of the DNAzyme-DNA template assembly brings several advantages in the synthesis of para-coupling PANI, including the region-selective growth of PANI, facilitating the formation of a para-coupling structure and facile regulation. We believe this study contributes significantly to the fabrication of doped PANI nanopatterns with controlled complexity, and the development of DNA nanotechnology.

Internal reflection spectroscopic analysis of sulphide mineral surfaces

International Nuclear Information System (INIS)

Kaoma, J.

1989-01-01

To establish the reason for flotation of sulfide minerals in the absence of any conventional collector, internal reflection spectroscopic analysis (IRS) of their surfaces was conducted. sulfur, sulfates, thiosulfates, and hydrocarbonates have been detected on the surface of as-grand sulfide minerals. On sodium sulfide-treated surfaces, both sulfur and polysulfide have also been found to be present. From these findings, the flotation of sulfide minerals without collectors is discussed. (author). 26 refs

Development of Ultra-sensitive Laser Spectroscopic Analysis Technology

Energy Technology Data Exchange (ETDEWEB)

Cha, H. K.; Kim, D. H.; Song, K. S. (and others)

2007-04-15

Laser spectroscopic analysis technology has three distinct merits in detecting various nuclides found in nuclear fields. High selectivity originated from small bandwidth of tunable lasers makes it possible to distinguish various kinds of isotopes and isomers. High intensity of focused laser beam makes it possible to analyze ultratrace amount. Remote delivery of laser beam improves safety of workers who are exposed in dangerous environment. Also it can be applied to remote sensing of environment pollution.

Development of Ultra-sensitive Laser Spectroscopic Analysis Technology

International Nuclear Information System (INIS)

Cha, H. K.; Kim, D. H.; Song, K. S.

2007-04-01

Laser spectroscopic analysis technology has three distinct merits in detecting various nuclides found in nuclear fields. High selectivity originated from small bandwidth of tunable lasers makes it possible to distinguish various kinds of isotopes and isomers. High intensity of focused laser beam makes it possible to analyze ultratrace amount. Remote delivery of laser beam improves safety of workers who are exposed in dangerous environment. Also it can be applied to remote sensing of environment pollution

A facile route towards the synthesis of 2-(1H-indol-3-yl)-acetamides using 1,1-carbonyldiimidazole

International Nuclear Information System (INIS)

Kanwal, F.; Khan, K.M.; Fatima, B.; Bano, B.; Salar, U.

2016-01-01

A base-catalyzed one pot reaction has been developed for the synthesis of 2-(1H-indol-3-yl)-acetamides via coupling of 1,1-carbonyldiimidazole with 2-(1H-indol-3-yl) acetic acid resulting in the formation of a reactive intermediate which on treatment with different substituted anilines afford 2-(1H-indol-3-yl)-acetamides in good yield. The use of base along with coupling reagent eases the formation of intermediate in minimum time. All the synthetic compounds were obtained in good to moderate yields, the use of various substituted anilines effects the yields of the products. Compounds 4-30 were synthesized and the structures of all the synthetic compounds were determined by using spectroscopic techniques such as 1H-, 13C-NMR, EIMS and HRMS. (author)

Synthesis, Spectral, and In Vitro Antibacterial Studies of Organosilicon(IV) Complexes with Schiff Bases Derived from Amino Acids.

Science.gov (United States)

Singh, Har Lal; Singh, Jangbhadur; Mukherjee, A

2013-01-01

The present work stems from our interest in the synthesis, characterization, and antibacterial evaluation of organosilicon(IV) complexes of a class of amino-acid-based Schiff base which have been prepared by the interaction of ethoxytrimethylsilane with the Schiff bases (N OH) in 1 : 1 molar ratio. These complexes have been characterized by elemental analysis, molar conductance, and spectroscopic studies including electronic IR and NMR ((1)H, (13)C, and (29)Si) spectroscopy. The analytical and spectral data suggest trigonal bipyramidal geometry around the silicon atom in the resulting complexes. The ligands and their organosilicon complexes have also been evaluated for in vitro antimicrobial activity against bacteria (Bacillus cereus, Nocardia spp., E. aerogenes, Escherichia coli, Klebsiella spp., and Staphylococcus spp.). The complexes were found to be more potent as compared to the ligands.

Synthesis and Characterization of Some Alkaline-Earth-Oxide Nanoparticles

Science.gov (United States)

Singh, Jitendra Pal; Lim, Weon Cheol; Won, Sung Ok; Song, Jonghan; Chae, Keun Hwa

2018-04-01

The present work reports the synthesis of MgO and CaO nanoparticles by using the sol-gel autocombustion method. The annealing of the precursor at 1200 °C was observed to lead the formation of MgO nanoparticles having average crystallite size of 31 nm. Annealing the precursor at same temperature produced materials having a CaO phase with a minor impure phase of calcium carbonate ( 3%). The crystallite size corresponding to the CaO phase was 38 nm. A change of thermal history in the precursor was observed not to result in an improvement of the CaO phase. The change of thermal history in the precursor gave rise to mixed phases of CaCO3 and Ca(OH)2 rather than the phase of CaO. Further, annealing at 1200 °C for 12 h resulted in the formation of the CaO phase along with almost 1 - 5% of calcium hydroxide as an impurity phase. X-ray absorption spectroscopic measurements carried out on these materials revealed that the local electronic/atomic structure of these oxides was not only affected by the impurity phases but also influenced by the carbaneous impurities attached to the crystallites.

SYNTHESES, SPECTROSCOPIC AND MAGNETIC PROPERTIES ...

African Journals Online (AJOL)

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suspension of II reacts with Mn(II), Ni(II), Cd(II), Fe(III) and UO2(VI) ions and ... There has been considerable interest in the synthesis and use of ... chelating abilities in recent years due to their practical convenience, operational flexibility and.

Spectroscopic characterization of galaxy clusters in RCS-1: spectroscopic confirmation, redshift accuracy, and dynamical mass-richness relation

Science.gov (United States)

Gilbank, David G.; Barrientos, L. Felipe; Ellingson, Erica; Blindert, Kris; Yee, H. K. C.; Anguita, T.; Gladders, M. D.; Hall, P. B.; Hertling, G.; Infante, L.; Yan, R.; Carrasco, M.; Garcia-Vergara, Cristina; Dawson, K. S.; Lidman, C.; Morokuma, T.

2018-05-01

We present follow-up spectroscopic observations of galaxy clusters from the first Red-sequence Cluster Survey (RCS-1). This work focuses on two samples, a lower redshift sample of ˜30 clusters ranging in redshift from z ˜ 0.2-0.6 observed with multiobject spectroscopy (MOS) on 4-6.5-m class telescopes and a z ˜ 1 sample of ˜10 clusters 8-m class telescope observations. We examine the detection efficiency and redshift accuracy of the now widely used red-sequence technique for selecting clusters via overdensities of red-sequence galaxies. Using both these data and extended samples including previously published RCS-1 spectroscopy and spectroscopic redshifts from SDSS, we find that the red-sequence redshift using simple two-filter cluster photometric redshifts is accurate to σz ≈ 0.035(1 + z) in RCS-1. This accuracy can potentially be improved with better survey photometric calibration. For the lower redshift sample, ˜5 per cent of clusters show some (minor) contamination from secondary systems with the same red-sequence intruding into the measurement aperture of the original cluster. At z ˜ 1, the rate rises to ˜20 per cent. Approximately ten per cent of projections are expected to be serious, where the two components contribute significant numbers of their red-sequence galaxies to another cluster. Finally, we present a preliminary study of the mass-richness calibration using velocity dispersions to probe the dynamical masses of the clusters. We find a relation broadly consistent with that seen in the local universe from the WINGS sample at z ˜ 0.05.

Synthesis, spectroscopic and structural characterization of 5-benzoyl-4-phenyl-2-methylthio-1H-pyrimidine with theoretical calculations using density functional theory

Science.gov (United States)

İnkaya, Ersin; Dinçer, Muharrem; Şahan, Emine; Yıldırım, İsmail

2013-10-01

In this paper, we will report a combined experimental and theoretical investigation of the molecular structure and spectroscopic parameters (FT-IR, 1H NMR, 13C NMR) of 5-benzoyl-4-phenyl-2-methylthio-1H-pyrimidine. The compound crystallizes in the triclinic space group P-1 with Z = 2. The molecular geometry was also optimized using density functional theory (DFT/B3LYP) method with the 6-311G(d,p) and 6-311++G(d,p) basis sets in ground state and compared with the experimental data. All the assignments of the theoretical frequencies were performed by potential energy distributions using VEDA 4 program. Information about the size, shape, charge density distribution and site of chemical reactivity of the molecules has been obtained by mapping electron density isosurface with electrostatic potential (ESP). Also, non-linear optical properties of the title compound were performed at B3LYP/6-311++G(d,p) level. The theoretical results showed an excellent agreement with the experimental values.

In situ synthesis of copper nanoparticles on SBA-16 silica spheres

Directory of Open Access Journals (Sweden)

Asma Tufail Shah

2016-07-01

Full Text Available A chemical method for in situ synthesis of copper nanoparticles on SBA-16 silica spheres under ambient conditions has been reported. The silica support has been introduced into copper precursor solution before chemical reduction. Metal ions diffuse into mesopores (pore diameter 5–7 nm of silica where in situ reduction by hydrazine leads to formation of nanoparticles. These mesopores act as nanoreactor and their walls prevent metal particle’s agglomeration by providing a physical barrier. The obtained copper nanoparticles have been investigated by electron microscopy, X-ray diffraction, UV–Visible spectroscopy, Fourier transform Infra-red spectroscopy and thermogravimetric analyzer. SEM, TEM and UV–Visible spectroscopic images revealed that nanosized particles have been successfully synthesized by this method. Thermogravimetric investigations revealed that copper nanoparticles impregnated on silica were thermally more stable compared to unsupported nanoparticles. Silica not only helps in maintaining the particle size but also makes nanoparticles stable at high temperatures due to its thick pore walls. Macro sized silica support also makes separation/handling of nanoparticles easy and simple.

Green Synthesis of Silver Nanoparticles by using Eucalyptus Globulus Leaf Extract

Science.gov (United States)

Balamurugan, Madheswaran; Saravanan, Shanmugam

2017-12-01

A single step eco-friendly, energy efficient and economically scalable green method was employed to synthesize silver nanoparticles. In this work, the synthesis of silver nanoparticles using Eucalyptus globulus leaf extract as reducing and capping agent along with water as solvent at normal room temperature is described. Silver nanoparticles were prepared from aqueous silver nitrate solution by adding the leaf extract. The prepared nanoparticles were characterized by using UV-visible Spectrophotometer, X-ray diffractometer, High Resolution Transmission Electron Microscope (HR-TEM) and Fourier Transform Infrared Spectroscope (FTIS). X-ray diffraction studies brought to light the crystalline nature and the face centered cubic structure of the silver nanoparticles. Using HR-TEM. the nano sizes and morphology of the particles were studied. The mean sizes of the prepared silver nanoparticles ranged from 30 to 36 nm. The density of the particles was tuned by varying the molar ratio of silver nitrate. FTIS studies showed the functional group of organic molecules which were located on the surface of the silver nanoparticles. Originating from the leaf extracts, these organic molecules reduced and capped the particles.

Spectroscopic information from (3He, 7Be) reaction on 12C and 24Mg

International Nuclear Information System (INIS)

Rahman, Md.A.; Sen Gupta, H.M.

1986-01-01

The reaction ( 3 He, 7 Be) on 12 C and 24 Mg has been analysed using four discrete potential families for 7 Be channel and one discrete potential family for 3 He channel to extract alpha spectroscopic factors. It is shown that the relative spectroscopic factors are reliable if they are calculated staying within one potential family (S( 24 Mg/ 12 C) approx. 0.12). But, changing the potential family between 12 C and 24 Mg, one obtains the extreme cases, such as S( 24 Mg/ 12 C) = 0.025 and 0.51, i.e. 1:20

Bulletin of Materials Science | Indian Academy of Sciences

Indian Academy of Sciences (India)

1151. Yb and Er co-doped Y2Ce2O7 nanoparticles: synthesis and spectroscopic properties ... Co-precipitation synthesis and upconversion luminescence properties of ZrO2:Yb-Ho · Jinsheng Liao Shaohua Liu Liling Nie Suijun Liu Junxiang Fu.

Bi-template assisted synthesis of mesoporous manganese oxide nanostructures: Tuning properties for efficient CO oxidation.

Science.gov (United States)

Roy, Mouni; Basak, Somjyoti; Naskar, Milan Kanti

2016-02-21

A simple soft bi-templating process was used for the synthesis of mesoporous manganese oxide nanostructures using KMnO4 as a precursor and polyethylene glycol and cetyltrimethylammonium bromide as templates in the presence of benzaldehyde as an organic additive in alkaline media, followed by calcination at 400 °C. X-ray diffraction and Raman spectroscopic analysis of the calcined products confirmed the existence of stoichiometric (MnO2 and Mn5O8) and non-stoichiometric mixed phases (MnO2 + Mn5O8) of Mn oxides obtained by tuning the concentration of the additive and the synthesis time. The surface properties of the prepared Mn oxides were determined by X-ray photoelectron spectroscopy. The mesoporosity of the samples was confirmed by N2 adsorption-desorption. Different synthetic conditions resulted in the formation of different morphologies of the Mn oxides (α-MnO2, Mn5O8, and α-MnO2 + Mn5O8), such as nanoparticles, nanorods, and nanowires. The synthesized mesoporous Mn oxide nanostructures were used for the catalytic oxidation of the harmful air pollutant carbon monoxide. The Mn5O8 nanoparticles with the highest Brunauer-Emmett-Teller surface area and the non-stoichiometric manganese oxide (α-MnO2 + Mn5O8) nanorods with a higher Mn(3+) concentration had the best catalytic efficiency.

Synthesis of low-oxide blue luminescent alkyl-functionalized silicon nanoparticles with no nitrogen containing surfactant

International Nuclear Information System (INIS)

Thomas, Jason A.; Ashby, Shane P.; Huld, Frederik; Pennycook, Timothy J.; Chao, Yimin

2015-01-01

Of ever growing interest in the fields of physical chemistry and materials science, silicon nanoparticles show a great deal of potential. Methods for their synthesis are, however, often hazardous, expensive or otherwise impractical. In the literature, there is a safe, fast and cheap inverse micelle-based method for the production of alkyl-functionalized blue luminescent silicon nanoparticles, which nonetheless found limitations, due to undesirable Si-alkoxy and remaining Si–H functionalization. In the following work, these problems are addressed, whereby an optimisation of the reaction mechanism encourages more desirable capping, and the introduction of alcohol is replaced by the use of anhydrous copper (II) chloride. The resulting particles, when compared with their predecessors through a myriad of spectroscopic techniques, are shown to have greatly reduced levels of ‘undesirable’ capping, with a much lower surface oxide level; whilst also maintaining long-term air stability, strong photoluminescence and high yields

Electrochemical synthesis and characterization of stable colloidal suspension of graphene using two-electrode cell system

Energy Technology Data Exchange (ETDEWEB)

Danial, Wan Hazman, E-mail: hazmandanial@gmail.com; Majid, Zaiton Abdul, E-mail: zaiton@kimia.fs.utm.my; Aziz, Madzlan [Department of Chemistry, Faculty of Science, Universiti Teknologi Malaysia (UTM), 81310 Skudai, Johor (Malaysia); Chutia, Arunabhiram [Institute of Fluid Sciences, Tohoku University, Sendai 980-8577 (Japan); Sahnoun, Riadh [Ibnu Sina Institute for Fundamental Science Studies, Universiti Teknologi Malaysia (UTM), 81310 Skudai, Johor (Malaysia)

2015-07-22

The present work reports the synthesis and characterization of graphene via electrochemical exfoliation of graphite rod using two-electrode system assisted by Sodium Dodecyl Sulphate (SDS) as a surfactant. The electrochemical process was carried out with sequence of intercalation of SDS onto the graphite anode followed by exfoliation of the SDS-intercalated graphite electrode when the anode was treated as cathode. The effect of intercalation potential from 5 V to 9 V and concentration of the SDS surfactant of 0.1 M and 0.01 M were investigated. UV-vis Spectroscopic analysis indicated an increase in the graphene production with higher intercalation potential. Transmission Electron Microscopy (TEM) analysis showed a well-ordered hexagonal lattice of graphene image and indicated an angle of 60° between two zigzag directions within the honeycomb crystal lattice. Raman spectroscopy analysis shows the graphitic information effects after the exfoliation process.

Synthesis of low-oxide blue luminescent alkyl-functionalized silicon nanoparticles with no nitrogen containing surfactant

Energy Technology Data Exchange (ETDEWEB)

Thomas, Jason A.; Ashby, Shane P.; Huld, Frederik [University of East Anglia, School of Chemistry (United Kingdom); Pennycook, Timothy J. [SuperSTEM Laboratory, STFC Daresbury Campus (United Kingdom); Chao, Yimin, E-mail: y.chao@uea.ac.uk [University of East Anglia, School of Chemistry (United Kingdom)

2015-05-15

Of ever growing interest in the fields of physical chemistry and materials science, silicon nanoparticles show a great deal of potential. Methods for their synthesis are, however, often hazardous, expensive or otherwise impractical. In the literature, there is a safe, fast and cheap inverse micelle-based method for the production of alkyl-functionalized blue luminescent silicon nanoparticles, which nonetheless found limitations, due to undesirable Si-alkoxy and remaining Si–H functionalization. In the following work, these problems are addressed, whereby an optimisation of the reaction mechanism encourages more desirable capping, and the introduction of alcohol is replaced by the use of anhydrous copper (II) chloride. The resulting particles, when compared with their predecessors through a myriad of spectroscopic techniques, are shown to have greatly reduced levels of ‘undesirable’ capping, with a much lower surface oxide level; whilst also maintaining long-term air stability, strong photoluminescence and high yields.

Synthesis and Structural Characterization of 1- and 2-Substituted Indazoles: Ester and Carboxylic Acid Derivatives

Directory of Open Access Journals (Sweden)

Isabel Bento

2006-11-01

Full Text Available A series of indazoles substituted at the N-1 and N-2 positions with ester-containing side chains -(CH2nCO2R of different lengths (n = 0-6, 9, 10 are described.Nucleophilic substitution reactions on halo esters (X(CH2nCO2R by 1H-indazole inalkaline solution lead to mixtures of N-1 and N-2 isomers, in which the N-1 isomerpredominates. Basic hydrolysis of the ester derivatives allowed the synthesis of thecorresponding indazole carboxylic acids. All compounds were fully characterised bymultinuclear NMR and IR spectroscopies, MS spectrometry and elemental analysis; theNMR spectroscopic data were used for structural assignment of the N-1 and N-2 isomers.The molecular structure of indazol-2-yl-acetic acid (5b was determined by X-raydiffraction, which shows a supramolecular architecture involving O2-H...N1intermolecular hydrogen bonds.

Electrochemical synthesis and spectroscopic characterization of poly(N-phenylpyrrole coatings in an organic medium on iron and platinum electrodes

Directory of Open Access Journals (Sweden)

A.K.D. Diaw

2008-12-01

Full Text Available The electrochemical synthesis of poly(N-phenylpyrrole film was achieved on pretreated iron and platinum electrodes in acetonitrile solutions containing 0.1 M N-phenylpyrrole as the monomer and 0.1 M tetrabutylammonium trifluoromethane sulfonate (Bu4NCF3SO3 as the supporting-salt. The results showed that a surface treatment by 10 % aqueous nitric acid inhibits iron dissolution without preventing the N-phenylpyrrole oxidation. Very strongly adherent films were obtained at constant-potential, constant-current and cyclic voltammetry. XPS measurements, infrared (FT-IR and electronic absorption (UV-vis spectroscopies were used to characterize the iron and platinum-coated electrodes. Finally the anticorrosion properties of the PΦP film were evidenced.

Evaluation of multivariate calibration models transferred between spectroscopic instruments

DEFF Research Database (Denmark)

Eskildsen, Carl Emil Aae; Hansen, Per W.; Skov, Thomas

2016-01-01

In a setting where multiple spectroscopic instruments are used for the same measurements it may be convenient to develop the calibration model on a single instrument and then transfer this model to the other instruments. In the ideal scenario, all instruments provide the same predictions for the ......In a setting where multiple spectroscopic instruments are used for the same measurements it may be convenient to develop the calibration model on a single instrument and then transfer this model to the other instruments. In the ideal scenario, all instruments provide the same predictions...... for the same samples using the transferred model. However, sometimes the success of a model transfer is evaluated by comparing the transferred model predictions with the reference values. This is not optimal, as uncertainties in the reference method will impact the evaluation. This paper proposes a new method...... for calibration model transfer evaluation. The new method is based on comparing predictions from different instruments, rather than comparing predictions and reference values. A total of 75 flour samples were available for the study. All samples were measured on ten near infrared (NIR) instruments from two...

Spectroscopic observations of AG Dra

International Nuclear Information System (INIS)

Chang-Chun, H.

1982-01-01

During summer 1981, spectroscopic observations of AG Dra were performed at the Haute-Provence Observatory using the Marly spectrograph with a dispersion of 80 A mm -1 at the 120 cm telescope and using the Coude spectrograph of the 193 cm telescope with a dispersion of 40 A mm -1 . The actual outlook of the spectrum of AG Dra is very different from what it was in 1966 in the sense that only a few intense absorption lines remain, the heavy emission continuum masking the absorption spectrum, while on the 1966 plate, about 140 absorption lines have been measured. Numerous emission lines have been measured, most of them, present in 1981, could also be detected in 1966. They are due to H, HeI and HeII. (Auth.)

Synthesis, structural characterization, Hirshfeld surface analysis and spectroscopic studies of cadmium (II) chloride complex with 4-hydroxy-1-methylpiperidine

Energy Technology Data Exchange (ETDEWEB)

Soudani, S. [Université de Carthage, Laboratoire de Chimie des Matériaux, Faculté des Sciences de Bizerte, 7021 Zarzouna (Tunisia); Ferretti, V. [Department of Chemical and Pharmaceutical Sciences and Center for Structural Diffractometry, via Fossato di Mortara 17, I-44121 Ferrara (Italy); Jelsch, C. [CRM2, CNRS, Institut Jean Barriol, Université de Lorraine, Vandoeuvre les Nancy CEDEX (France); Lefebvre, F. [Laboratoire de Chimie Organométallique de Surface (LCOMS), Ecole Supérieure de Chimie Physique Electronique, 69626 Villeurbanne Cedex (France); Nasr, C. Ben, E-mail: cherif_bennasr@yahoo.fr [Université de Carthage, Laboratoire de Chimie des Matériaux, Faculté des Sciences de Bizerte, 7021 Zarzouna (Tunisia)

2016-05-15

The chemical preparation, crystal structure, Hirshfeld surface analysis and spectroscopic characterization of the novel cadmium (II) 4-hydroxy-1-methylpiperidine complex, Cd{sub 4}Cl{sub 10}(C{sub 6}H{sub 14}NO){sub 2}·2H{sub 2}O, have been reported. The atomic arrangement can be described as built up by an anionic framework, formed by edge sharing CdCl{sub 6} and CdCl{sub 5}O octahedral linear chains spreading along the a-axis. These chains are interconnected by water molecules via O–H⋯Cl and O–H⋯O hydrogen bonds to form layers parallel to (011) plane. The organic cations are inserted between layers through C–H⋯Cl hydrogen bonds. Investigation of intermolecular interactions and crystal packing via Hirshfeld surface analysis reveals that the H{sub C}⋯Cl and H{sub C}⋯H{sub C} intermolecular interactions are the most abundant contacts of the organic cation in the crystal packing. The statistical analysis of crystal contacts reveals the driving forces in the packing formation. The {sup 13}C and {sup 15}N CP-MAS NMR spectra are in agreement with the X-ray structure. The vibrational absorption bands were identified by infrared spectroscopy. DFT calculations allowed the attribution of the NMR peaks and of the IR bands.

Velocity Curve Analysis of the Spectroscopic Binary Stars PV Pup ...

Indian Academy of Sciences (India)

are in good agreement with those obtained using the method of Lehmann-. Filhés. Key words. ... use their method to obtain the orbital elements of the four double-lined spectroscopic binary systems PV Pup, HD ... Observation shows that the photometric phase, φ, which is measured from the pho- tometric reference point ...

Discovery of Two New Hypervelocity Stars from the LAMOST Spectroscopic Surveys

Energy Technology Data Exchange (ETDEWEB)

Huang, Y.; Liu, X.-W.; Chen, B.-Q. [South-Western Institute for Astronomy Research, Yunnan University, Kunming 650500 (China); Zhang, H.-W.; Wang, C.; Tian, Z.-J. [Department of Astronomy, Peking University, Beijing 100871 (China); Xiang, M.-S.; Li, Y.-B. [Key Laboratory of Optical Astronomy, National Astronomical Observatories, Chinese Academy of Sciences, Beijing 100012 (China); Yuan, H.-B. [Department of Astronomy, Beijing Normal University, Beijing 100875 (China); Wang, B., E-mail: yanghuang@pku.edu.cn, E-mail: x.liu@pku.edu.cn, E-mail: zhanghw@pku.edu.cn [Key Laboratory for the Structure and Evolution of Celestial Objects, Yunnan Observatories, CAS, Kunming 650216 (China)

2017-09-20

We report the discovery of two new unbound hypervelocity stars (HVSs) from the LAMOST spectroscopic surveys. They are, respectively, a B2V-type star of ∼7 M {sub ⊙} with a Galactic rest-frame radial velocity of 502 km s{sup −1} at a Galactocentric radius of ∼21 kpc and a B7V-type star of ∼4 M {sub ⊙} with a Galactic rest-frame radial velocity of 408 km s{sup −1} at a Galactocentric radius of ∼30 kpc. The origins of the two HVSs are not clear given their currently poorly measured proper motions. However, the future data releases of Gaia should provide proper motion measurements accurate enough to solve this problem. The ongoing LAMOST spectroscopic surveys are expected to yield more HVSs to form a statistical sample, providing vital constraints on understanding the nature of HVSs and their ejection mechanisms.

Application of Spectroscopic Methods for Structural Analysis of Chitin and Chitosan

Directory of Open Access Journals (Sweden)

Jolanta Kumirska

2010-04-01

Full Text Available Chitin, the second most important natural polymer in the world, and its N-deacetylated derivative chitosan, have been identified as versatile biopolymers for a broad range of applications in medicine, agriculture and the food industry. Two of the main reasons for this are firstly the unique chemical, physicochemical and biological properties of chitin and chitosan, and secondly the unlimited supply of raw materials for their production. These polymers exhibit widely differing physicochemical properties depending on the chitin source and the conditions of chitosan production. The presence of reactive functional groups as well as the polysaccharide nature of these biopolymers enables them to undergo diverse chemical modifications. A complete chemical and physicochemical characterization of chitin, chitosan and their derivatives is not possible without using spectroscopic techniques. This review focuses on the application of spectroscopic methods for the structural analysis of these compounds.

Spectroscopic and chromatographic analysis of oil from an oil shale flash pyrolysis unit

Energy Technology Data Exchange (ETDEWEB)

Khraisha, V.H.; Irqsousi, N.A. [University of Jordan, Amman (Jordan). Dept. of Chemical Engineering; Shabib, I.M. [Applied Science Univ., Amman (Jordan). Dept. of Chemistry

2003-01-01

In this investigation, spectroscopic (FT-IR, UV-Vis, {sup 1}H NMR) and chromatographic (GC) techniques were used to analyze two Jordanian shale oils, Sultani and El-Lajjun. The oils were extracted at different pyrolysis temperatures (400-500{sup o}C) using a fluidized bed reactor. The spectroscopic and chromatographic analyses show that the variation of pyrolysis temperature has no significant effect on the composition of the produced oil. The {sup 1}H NMR results indicate that the protons of methyl and methelyene represent the bulk of the hydrogen ({approx}90%) in most shale oil samples. GC analysis reveals that the oil samples contain n-alkanes with a predominant proportion of n-C{sub 25}. (Author)

Detonation-synthesis nanodiamonds: synthesis, structure, properties and applications

Energy Technology Data Exchange (ETDEWEB)

Dolmatov, Valerii Yu [Federal State Unitary Enterprise Special Design-Technology Bureau (FSUE SDTB) ' ' Tekhnolog' ' at the St Petersburg State Institute of Technology (Technical University) (Russian Federation)

2007-04-30

The review outlines the theoretical foundations and industrial implementations of modern detonation synthesis of nanodiamonds and chemical purification of the nanodiamonds thus obtained. The structure, key properties and promising fields of application of detonation-synthesis nanodiamonds are considered.

Detonation-synthesis nanodiamonds: synthesis, structure, properties and applications

International Nuclear Information System (INIS)

Dolmatov, Valerii Yu

2007-01-01

The review outlines the theoretical foundations and industrial implementations of modern detonation synthesis of nanodiamonds and chemical purification of the nanodiamonds thus obtained. The structure, key properties and promising fields of application of detonation-synthesis nanodiamonds are considered.

Spectroscopic Classifications of Optical Transients with the Lick Shane 3-m telescope

Science.gov (United States)

Dimitriadis, G.; Foley, R. J.

2018-05-01

We report the following classifications of optical transients from spectroscopic observations with the Kast spectrograph on the Shane 3-m telescope. Targets were supplied by ATLAS, ASAS-SN, and the KEGS K2 SN search.

LaPO4:Eu fluorescent nanorods, synthesis, characterization and spectroscopic studies on interaction with human serum albumin

Science.gov (United States)

Guo, Xingjia; Yao, Jie; Liu, Xuehui; Wang, Hongyan; Zhang, Lizhi; Xu, Liping; Hao, Aijun

2018-06-01

Eu3+ doped LaPO4 fluorescent nanorods (LaPO4:Eu) was successfully fabricated by a hydrothermal process. The obtained LaPO4:Eu nanorods under the optimal conditions were characterized by means of transmission electron microscopy (TEM), X-ray diffraction (XRD) technique, Fourier transform infrared (FTIR), UV-vis absorption and fluorescence spectroscopy. The nanorods with a length of 50-100 nm and a diameter of about 10 nm, can emit strong red fluorescence upon excitation at 241 nm. The FTIR result confirmed that there are lots of phosphate groups on the surfaces of nanorods. In order to better understand the physiological behavior of nanorods in human body, multiple spectroscopic methods were used to study the interaction between the LaPO4:Eu nanorods and human serum albumin (HSA) in the simulated physiological conditions. The results indicated that the nanorods can effectively quench the intrinsic fluorescence of HSA through a dynamic quenching mode with the association constants of the order of 103 L mol-1. The values of the thermodynamic parameters suggested that the binding of the nanorods to HSA was a spontaneous process and van der Waals forces and hydrogen bonds played a predominant role. The displacement experiments verified that the binding site of nanorods on HSA was mainly located in the hydrophobic pocket of subdomain IIA (site I) of HSA. The binding distance between nanorods and HSA was calculated to be 4.2 nm according to the theory of Förster non-radiation energy transfer. The analysis of synchronous fluorescence, three-dimensional fluorescence (3D) and circular dichroism (CD) spectra indicated that there the addition of LaPO4:Eu nanorods did not caused significant alterations in conformation of HSA secondary structure and the polarity around the amino acid residues.

Synthesis, structure and solvatochromic properties of some novel 5-arylazo-6-hydroxy-4-phenyl-3-cyano-2-pyridone dyes

Directory of Open Access Journals (Sweden)

Alimmari Adel

2012-07-01

Full Text Available Abstract Background A series of some novel arylazo pyridone dyes was synthesized from the corresponding diazonium salt and 6-hydroxy-4-phenyl-3-cyano-2-pyridone using a classical reaction for the synthesis of the azo compounds. Results The structure of the dyes was confirmed by UV-vis, FT-IR, 1H NMR and 13C NMR spectroscopic techniques and elemental analysis. The solvatochromic behavior of the dyes was evaluated with respect to their visible absorption properties in various solvents. Conclusions The azo-hydrazone tautomeric equilibration was found to depend on the substituents as well as on the solvent. The geometry data of the investigated dyes were obtained using DFT quantum-chemical calculations. The obtained calculational results are in very good agreement with the experimental data.

Spectroscopic link between adsorption site occupation and local surface chemical reactivity

DEFF Research Database (Denmark)

Baraldi, A.; Lizzit, S.; Comelli, G.

2004-01-01

rules, from which adsorption sites are directly determined. Theoretical calculations rationalize the results for transition metal surfaces in terms of the energy shift of the d-band center of mass and this proves that adsorbate-induced SCL shifts provide a spectroscopic measure of local surface...

Green synthesis of silver nanoparticles from Moringa oleifera leaf extracts and its antimicrobial potential

Science.gov (United States)

Moodley, Jerushka S.; Babu Naidu Krishna, Suresh; Pillay, Karen; Sershen; Govender, Patrick

2018-03-01

In this study we report on the synthesis of silver nanoparticles (AgNPs) from the leaf extracts of Moringa oleifera using sunlight irradiation as primary source of energy, and its antimicrobial potential. Silver nanoparticle formation was confirmed by surface plasmon resonance at 450 nm and 440 nm, respectively for both fresh and freeze-dried leaf samples. Crystanality of AgNPs was confirmed by transmission electron microscopy, scanning electron microscopy with energy dispersive x-ray spectroscopy and Fourier transform infrared (FTIR) spectroscopy analysis. FTIR spectroscopic analysis suggested that flavones, terpenoids and polysaccharides predominate and are primarily responsible for the reduction and subsequent capping of AgNPs. X-ray diffraction analysis also demonstrated that the size range of AgNPs from both samples exhibited average diameters of 9 and 11 nm, respectively. Silver nanoparticles showed antimicrobial activity on both bacterial and fungal strains. The biosynthesised nanoparticle preparations from M. oleifera leaf extracts exhibit potential for application as broad-spectrum antimicrobial agents.

Design, synthesis, α-glucosidase inhibitory activity, molecular docking and QSAR studies of benzimidazole derivatives

Science.gov (United States)

Dinparast, Leila; Valizadeh, Hassan; Bahadori, Mir Babak; Soltani, Somaieh; Asghari, Behvar; Rashidi, Mohammad-Reza

2016-06-01

In this study the green, one-pot, solvent-free and selective synthesis of benzimidazole derivatives is reported. The reactions were catalyzed by ZnO/MgO containing ZnO nanoparticles as a highly effective, non-toxic and environmentally friendly catalyst. The structure of synthesized benzimidazoles was characterized using spectroscopic technics (FT-IR, 1HNMR, 13CNMR). Synthesized compounds were evaluated for their α-glucosidase inhibitory potential. Compounds 3c, 3e, 3l and 4n were potent inhibitors with IC50 values ranging from 60.7 to 168.4 μM. In silico studies were performed to explore the binding modes and interactions between enzyme and synthesized benzimidazoles. Developed linear QSAR model based on density and molecular weight could predict bioactivity of newly synthesized compounds well. Molecular docking studies revealed the availability of some hydrophobic interactions. In addition, the bioactivity of most potent compounds had good correlation with estimated free energy of binding (ΔGbinding) which was calculated according to docked best conformations.

Spectroscopic effects in 1H and 13C NMR spectra of 4,4'-di-substituted 3,3'-diquinolines sulfides

International Nuclear Information System (INIS)

Pluta, K.

1994-01-01

The 1 H and 13 C NMR spectra of 4,4'-disubstituted sulfides of 3,3'-quinolines have been studied in CDCl 3 solutions. The observed spectroscopic effects have been interpreted in terms of molecule structure and configuration. The factors being responsible for the value of spectroscopic effects have been discussed

Trace detection of tetrahydrocannabinol (THC) with a SERS-based capillary platform prepared by the in situ microwave synthesis of AgNPs.

Science.gov (United States)

Yüksel, Sezin; Schwenke, Almut M; Soliveri, Guido; Ardizzone, Silvia; Weber, Karina; Cialla-May, Dana; Hoeppener, Stephanie; Schubert, Ulrich S; Popp, Jürgen

2016-10-05

In the present study, an ultra-sensitive and highly reproducible novel SERS-based capillary platform was developed and utilized for the trace detection of tetrahydrocannabinol (THC). The approach combines the advantages of microwave-assisted nanoparticle synthesis, plasmonics and capillary forces. By employing a microwave-assisted preparation method, glass capillaries were reproducibly coated with silver nanoparticles in a batch fabrication process that required a processing time of 3 min without needing to use any pre-surface modifications or add surfactants. The coated capillaries exhibited an excellent SERS activity with a high reproducibility and enabled the detection of low concentrations of target molecules. At the same time, only a small amount of analyte and a short and simple incubation process was required. The developed platform was applied to the spectroscopic characterization of tetrahydrocannabinol (THC) and its identification at concentration levels down to 1 nM. Thus, a highly efficient detection system for practical applications, e.g., in drug monitoring/detection, is introduced, which can be fabricated at low cost by using microwave-assisted batch synthesis techniques. Copyright © 2016 Elsevier B.V. All rights reserved.

Clues on the Milky Way disc formation from population synthesis simulations

Science.gov (United States)

Robin, A. C.; Reylé, C.; Bienaymé, O.; Fernandez-Trincado, J. G.; Amôres, E. B.

2016-09-01

In recent years the stellar populations of the Milky Way have been investigated from large scale surveys in different ways, from pure star count analysis to detailed studies based on spectroscopic surveys. While in the former case the data can constrain the scale height and scale length thanks to completeness, they suffer from high correlation between these two values. On the other hand, spectroscopic surveys suffer from complex selection functions which hardly allow to derive accurate density distributions. The scale length in particular has been difficult to be constrained, resulting in discrepant values in the literature. Here, we investigate the thick disc characteristics by comparing model simulations with large scale data sets. The simulations are done from the population synthesis model of Besançon. We explore the parameters of the thick disc (shape, local density, age, metallicity) using a Monte Carlo Markov Chain method to constrain the model free parameters (Robin et al. 2014). Correlations between parameters are limited due to the vast spatial coverage of the used surveys (SDSS + 2MASS). We show that the thick disc was created during a long phase of formation, starting about 12 Gyr ago and finishing about 10 Gyr ago, during which gravitational contraction occurred, both vertically and radially. Moreover, in its early phase the thick disc was flaring in the outskirts. We conclude that the thick disc has been created prior to the thin disc during a gravitational collapse phase, slowed down by turbulence related to a high star formation rate, as explained for example in Bournaud et al. (2009) or Lehnert et al. (2009). Our result does not favor a formation from an initial thin disc thickened later by merger events or by secular evolution of the thin disc. We then study the in-plane distribution of stars in the thin disc from 2MASS and show that the thin disc scale length varies as a function of age, indicating an inside out formation. Moreover, we

Theoretical study of H2/+/ spectroscopic properties. II, III. [2p and 3d excited electronic states

Science.gov (United States)

Beckel, C. L.; Shafi, M.; Peek, J. M.

1973-01-01

Description of the theoretical spectroscopic properties of the 2p pi/sub u/ and 3d sigma/sub g/ excited states of the H2/+/ hydrogen molecular ion. Numerical integration of the Schrodinger equation is used to determine vibration-rotation eigenvalues. Dunham power series expansions are used to determine the equilibrium separation, potential coefficients, and spectroscopic constants. The eigenvalues are used to determine delta-G, Bv, Dv, and Hv.

Pair Identity and Smooth Variation Rules Applicable for the Spectroscopic Parameters of H2O Transitions Involving High-J States

Science.gov (United States)

Ma, Q.; Tipping, R. H.; Lavrentieva, N. N.

2010-01-01

Two basic rules (i.e. the pair identity and the smooth variation) applicable for H2O transitions involving high-J states have been discovered. The origins of these rules are the properties of the energy levels and wavefunctions of H2O states with the quantum number J above certain boundaries. As a result, for lines involving high-J states in individually defined groups, all their spectroscopic parameters (i.e. the transition wavenumber, intensity, pressure-broadened half-width, pressure-induced shift, and temperature exponent) must follow these rules. One can use these rules to screen spectroscopic data provided by databases and to identify possible errors. In addition, by using extrapolation methods within the individual groups, one is able to predict the spectroscopic parameters for lines in this group involving very high-J states. The latter are required in developing high-temperature molecular spectroscopic databases such as HITEMP.

Spectroscopic study on the stability of morin in aqueous solution

Energy Technology Data Exchange (ETDEWEB)

Bark, Ki Min [Dept. of Chemical Education and Research Institute of Life Science, Gyeongsang National University, Chinju (Korea, Republic of); Im, Seo Eun; Seo, Jung Ja; Park, Ok Hyun; Park, Hyoung Ryun [Dept. of Chemistry, Chonnam National University, Gwangju (Korea, Republic of); Park, Chul Ho [Dept. of Cosmetic Science, Nambu University, Gwangju (Korea, Republic of)

2015-02-15

Morin (3,2,4,5,7-pentahydroxyflavone) is a flavonol conjugated to a resorcinol moiety at the C-2 position, different from many other flavonoids. The UV–vis spectrum of morin in neat water reveals two major absorption bands with maxima at 265 and 387 nm. The substance is stable in acidic solution and neat water. However, its absorption maximum at 387 nm continuously shifts to longer wavelengths and new peaks appeared at wavelengths of 312 nm with increasing pH of the solution. The shape of the absorption spectrum of morin depends on the storage time at a given pH, indicating the occurrence of other successive chemical reactions. The fluorescence spectroscopic results also prove that new conjugated double bonds are formed in the deaerated basic solution at the initial state and decompose with time. This behavior indicates that morin is very unstable, and therefore its decomposition occurs by a sequence of multistep reactions in basic solution. Probable reaction pathways for the reaction are suggested based on the spectroscopic results.

Recent advances in the applications of vibrational spectroscopic imaging and mapping to pharmaceutical formulations

Science.gov (United States)

Ewing, Andrew V.; Kazarian, Sergei G.

2018-05-01

Vibrational spectroscopic imaging and mapping approaches have continued in their development and applications for the analysis of pharmaceutical formulations. Obtaining spatially resolved chemical information about the distribution of different components within pharmaceutical formulations is integral for improving the understanding and quality of final drug products. This review aims to summarise some key advances of these technologies over recent years, primarily since 2010. An overview of FTIR, NIR, terahertz spectroscopic imaging and Raman mapping will be presented to give a perspective of the current state-of-the-art of these techniques for studying pharmaceutical samples. This will include their application to reveal spatial information of components that reveals molecular insight of polymorphic or structural changes, behaviour of formulations during dissolution experiments, uniformity of materials and detection of counterfeit products. Furthermore, new advancements will be presented that demonstrate the continuing novel applications of spectroscopic imaging and mapping, namely in FTIR spectroscopy, for studies of microfluidic devices. Whilst much of the recently developed work has been reported by academic groups, examples of the potential impacts of utilising these imaging and mapping technologies to support industrial applications have also been reviewed.

Synthesis, spectroscopic, computational (DFT/B3LYP), AChE inhibition and antioxidant studies of imidazole derivative

Science.gov (United States)

Ahmad, Faheem; Alam, Mohammad Jane; Alam, Mahboob; Azaz, Shaista; Parveen, Mehtab; Park, Soonheum; Ahmad, Shabbir

2018-01-01

The present study reports the synthesis and evaluation of biological properties of 3a,8a-dihydroxy-8-oxo-1,3,3a,8a-tetrahydroindeno[1,2-d]imidazol-2(1H)-iminium chloride (3). The structure was confirmed by the FTIR, NMR, MS, CHN microanalysis and X-ray crystallographic analysis. Quantum chemical calculations have been performed at B3LYP-D3/6-311++G(d,p) level of theory to study the molecular geometry, IR, (1H and 13C) NMR, UV/Vis spectra and other molecular parameters of the asymmetric unit of crystal of imidazole compound (3). An empirical dispersion correction to hybrid functional (B3LYP-D3) has been incorporated in the present calculations due to presence of non-covalent interaction, Cl⋯H-O, in the present compound. The remarkable agreement has been observed between theoretical data and those measured experimentally. Moreover, the Hirshfeld analysis was carried out to ascertain the secondary interactions and associated 2D fingerprint plots. The synthesized imidazole derivative showed promising antioxidant property and inhibitory activity against acetylcholinesterase (AChE). Molecular docking was also performed in order to explain in silico antioxidant studies and to ascertain the probable binding mode of compound with the amino acid residues of protein.

Spectroscopic factor of the 7He ground state

International Nuclear Information System (INIS)

Beck, F.; Frekers, D.; Neumann-Cosel, P. von; Richter, A.; Ryezayeva, N.; Thompson, I.J.

2007-01-01

The neutron spectroscopic factor S n of the 7 He ground state is extracted from an R-matrix analysis of a recent measurement of the 7 Li(d, 2 He) 7 He reaction with good energy resolution. The width extracted from a deconvolution of the spectrum is Γ=183(22) keV (full width at half maximum, FWHM). The result S n =0.64(9) is slightly larger than predictions of recent 'ab initio' Green's function Monte Carlo and fermionic molecular dynamics calculations

Novel spectroscopic techniques with using soft x-ray

International Nuclear Information System (INIS)

Gejo, Tatsuo

2010-01-01

Recent progress of experimental techniques related to synchrotron radiation makes possible of detail investigation of molecular dynamics after irradiation of soft X-ray. We introduce several novel spectroscopic techniques with using soft X-ray: Symmetry-resolved zero kinetic energy electron spectroscopy, symmetry-resolved metastable photofragment spectroscopy, soft X-ray emission spectroscopy, time-resolved fluorescence spectroscopy, and time-resolved-fluorescence mass-selected-ion coincidence spectroscopy. We also show new techniques performed by other groups at BL27SU in SPring-8. (author)

N-acetylcysteine stimulates protein synthesis in enterocytes independently of glutathione synthesis.

Science.gov (United States)

Yi, Dan; Hou, Yongqing; Wang, Lei; Long, Minhui; Hu, Shengdi; Mei, Huimin; Yan, Liqiong; Hu, Chien-An Andy; Wu, Guoyao

2016-02-01

Dietary supplementation with N-acetylcysteine (NAC) has been reported to improve intestinal health and treat gastrointestinal diseases. However, the underlying mechanisms are not fully understood. According to previous reports, NAC was thought to exert its effect through glutathione synthesis. This study tested the hypothesis that NAC enhances enterocyte growth and protein synthesis independently of cellular glutathione synthesis. Intestinal porcine epithelial cells were cultured for 3 days in Dulbecco's modified Eagle medium containing 0 or 100 μM NAC. To determine a possible role for GSH (the reduced form of glutathione) in mediating the effect of NAC on cell growth and protein synthesis, additional experiments were conducted using culture medium containing 100 μM GSH, 100 μM GSH ethyl ester (GSHee), diethylmaleate (a GSH-depletion agent; 10 μM), or a GSH-synthesis inhibitor (buthionine sulfoximine, BSO; 20 μM). NAC increased cell proliferation, GSH concentration, and protein synthesis, while inhibiting proteolysis. GSHee enhanced cell proliferation and GSH concentration without affecting protein synthesis but inhibited proteolysis. Conversely, BSO or diethylmaleate reduced cell proliferation and GSH concentration without affecting protein synthesis, while promoting protein degradation. At the signaling level, NAC augmented the protein abundance of total mTOR, phosphorylated mTOR, and phosphorylated 70S6 kinase as well as mRNA levels for mTOR and p70S6 kinase in IPEC-1 cells. Collectively, these results indicate that NAC upregulates expression of mTOR signaling proteins to stimulate protein synthesis in enterocytes independently of GSH generation. Our findings provide a hitherto unrecognized biochemical mechanism for beneficial effects of NAC in intestinal cells.

Multicomponent quantitative spectroscopic analysis without reference substances based on ICA modelling.

Science.gov (United States)

Monakhova, Yulia B; Mushtakova, Svetlana P

2017-05-01

A fast and reliable spectroscopic method for multicomponent quantitative analysis of targeted compounds with overlapping signals in complex mixtures has been established. The innovative analytical approach is based on the preliminary chemometric extraction of qualitative and quantitative information from UV-vis and IR spectral profiles of a calibration system using independent component analysis (ICA). Using this quantitative model and ICA resolution results of spectral profiling of "unknown" model mixtures, the absolute analyte concentrations in multicomponent mixtures and authentic samples were then calculated without reference solutions. Good recoveries generally between 95% and 105% were obtained. The method can be applied to any spectroscopic data that obey the Beer-Lambert-Bouguer law. The proposed method was tested on analysis of vitamins and caffeine in energy drinks and aromatic hydrocarbons in motor fuel with 10% error. The results demonstrated that the proposed method is a promising tool for rapid simultaneous multicomponent analysis in the case of spectral overlap and the absence/inaccessibility of reference materials.

Detection of the spectroscopic signatures of explosives and their degradation products

Science.gov (United States)

Florian, Vivian; Cabanzo, Andrea; Baez, Bibiana; Correa, Sandra; Irrazabal, Maik; Briano, Julio G.; Castro, Miguel E.; Hernandez-Rivera, Samuel P.

2005-06-01

Detection and removal of antipersonnel and antitank landmines is a great challenge and a worldwide enviromental and humanitarian problem. Sensors tuned on the spectroscopic signature of the chemicals released from mines are a potential solution. Enviromental factors (temperature, relative humidity, rainfall precipitation, wind, sun irradiation, pressure, etc.) as well as soil characteristics (water content, compaction, porosity, chemical composition, particle size distribution, topography, vegetation, etc), have a direct impact on the fate and transport of the chemicals released from landmines. Chemicals such as TNT, DNT and their degradation products, are semi-volatile, and somewhat soluble in water. Also, they may adsorb strongly to soil particles, and are susceptible to degradation by microorganisms, light, or chemical agents. Here we show an experimental procedure to quantify the effect of the above variables on the spectroscopic signature. A number of soil tanks under controlled conditions are used to study the effect of temperature, water content, relative humidity and light radiation.

Helium-plasma heating with a powerful proton beam for spectroscopic applications

International Nuclear Information System (INIS)

Arteev, M.S.; Kuznetsov, A.A.; Sulakshin, S.S.

1986-01-01

In this work the authors consider an ion gun which was especially developed for producing a gas plasma and report on the details of an experiment on (ELLIGIBLE) plasma spectroscopy. The current density of the proton beam was measured in the experiments on the axis of the gas tube with the aid of a collimating current collector with the wave impedance of a 75 omega cable. The ion gun was tested in the excitation of a helium plasma. Extremely pure helium with a pressure P = (0.2-1).10 5 Pa was employed. The proton gun which was developed satifies the requirements of spectroscopic plasma experiments and makes it possible to excite a plasma of inert gases under atmospheric pressure over a length of up to 100 cm, with the plasma having high homogeneity and stability. They obtained first results of spectroscopic measurements of the electron concentration of a helium plasma and the results agree with the theoretical predictions

PRISM: Processing routines in IDL for spectroscopic measurements (installation manual and user's guide, version 1.0)

Science.gov (United States)

Kokaly, Raymond F.

2011-01-01

This report describes procedures for installing and using the U.S. Geological Survey Processing Routines in IDL for Spectroscopic Measurements (PRISM) software. PRISM provides a framework to conduct spectroscopic analysis of measurements made using laboratory, field, airborne, and space-based spectrometers. Using PRISM functions, the user can compare the spectra of materials of unknown composition with reference spectra of known materials. This spectroscopic analysis allows the composition of the material to be identified and characterized. Among its other functions, PRISM contains routines for the storage of spectra in database files, import/export of ENVI spectral libraries, importation of field spectra, correction of spectra to absolute reflectance, arithmetic operations on spectra, interactive continuum removal and comparison of spectral features, correction of imaging spectrometer data to ground-calibrated reflectance, and identification and mapping of materials using spectral feature-based analysis of reflectance data. This report provides step-by-step instructions for installing the PRISM software and running its functions.

Sub-THz spectroscopic characterization of vibrational modes in artificially designed DNA monocrystal

International Nuclear Information System (INIS)

Sizov, Igor; Rahman, Masudur; Gelmont, Boris; Norton, Michael L.; Globus, Tatiana

2013-01-01

Highlights: • Sub-THz spectroscopy is used to characterize artificially designed DNA monocrystal. • Results are obtained using a novel near field, RT, frequency domain spectrometer. • Narrow resonances of 0.1 cm −1 width in absorption spectra of crystal are observed. • Signature measured between 310 and 490 GHz is reproducible and well resolved. • Absorption pattern is explained in part by simulation results from dsDNA fragment. - Abstract: Sub-terahertz (sub-THz) vibrational spectroscopy is a new spectroscopic branch for characterizing biological macromolecules. In this work, highly resolved sub-THz resonance spectroscopy is used for characterizing engineered molecular structures, an artificially designed DNA monocrystal, built from a short DNA sequence. Using a recently developed frequency domain spectroscopic instrument operating at room temperature with high spectral and spatial resolution, we demonstrated very intense and specific spectral lines from a DNA crystal in general agreement with a computational molecular dynamics (MD) simulation of a short double stranded DNA fragment. The spectroscopic signature measured in the frequency range between 310 and 490 GHz is rich in well resolved and reproducible spectral features thus demonstrating the capability of THz resonance spectroscopy to be used for characterizing custom macromolecules and structures designed and implemented via nanotechnology for a wide variety of application domains. Analysis of MD simulation indicates that intense and narrow vibrational modes with atomic movements perpendicular (transverse) and parallel (longitudinal) to the long DNA axis coexist in dsDNA, with much higher contribution from longitudinal vibrations

The double-lined spectroscopic binary Iota Pegasi

Science.gov (United States)

Fekel, F. C.; Tomkin, J.

1983-01-01

Reticon observations of the spectroscopic binary Iota Peg at 6430 A show the secondary star's weak, but well defined lines. Determinations have accordingly been made of the secondary velocity curve as well as that of the primary, together with the orbits and the minimum masses of the two components. The 1.31 + or - 0.02 and 0.81 + or - 0.01 solar mass minimum masses are sufficiently close to the expected actual masses to suggest eclipses, despite the relatively long, 10.2-day period. The spectral type of the secondary is estimated to be G8 V.

Transient full-field vibration measurement using spectroscopical stereo photogrammetry.

Science.gov (United States)

Yue, Kaiduan; Li, Zhongke; Zhang, Ming; Chen, Shan

2010-12-20

Contrasted with other vibration measurement methods, a novel spectroscopical photogrammetric approach is proposed. Two colored light filters and a CCD color camera are used to achieve the function of two traditional cameras. Then a new calibration method is presented. It focuses on the vibrating object rather than the camera and has the advantage of more accuracy than traditional camera calibration. The test results have shown an accuracy of 0.02 mm.

Synthesis and Identification of the Organic Reagent Ereochrom Black T and its Complex with Cobalt (lll

Directory of Open Access Journals (Sweden)

Jassem M. Abd Al Hassein

2017-02-01

Full Text Available The ligand 1–(4–Hydroxy –3–Naphthalene Azo–4–Nitro–8–Hydroxy–6–Sulfonic Naphthalene Acid Sodium Salt was synthesized (by the reaction between 3–amino–4– hydroxyl naphthalene and 3 – nitro – 7 – hydroxyl –5– sulfonic naphthalene acid sodium salt and characterized by FTIR technique, its ionization constants (PKs were determined. Synthesis and spectroscopic investigations of its complex with Co (III in aqueous solution revealed the sole formation of (1: 2 (metal: ligand complex. Specral and magnatic studies of the isolated complex indicates octahedral coordination via the N atoms of the azo groups and the O atoms of the hydroxyl groups. The molar conductivity of the complex was determined in an alcoholic solutions indicates that the complex has high molar conductivity. The magnetic properties were determined by using Gouy balance which indicates diamagnetic complex.

MOSS spectroscopic camera for imaging time resolved plasma species temperature and flow speed

International Nuclear Information System (INIS)

Michael, Clive; Howard, John

2000-01-01

A MOSS (Modulated Optical Solid-State) spectroscopic camera has been devised to monitor the spatial and temporal variations of temperatures and flow speeds of plasma ion species, the Doppler broadening measurement being made of spectroscopic lines specified. As opposed to a single channel MOSS spectrometer, the camera images light from plasma onto an array of light detectors, being mentioned 2D imaging of plasma ion temperatures and flow speeds. In addition, compared to a conventional grating spectrometer, the MOSS camera shows an excellent light collecting performance which leads to the improvement of signal to noise ratio and of time resolution. The present paper first describes basic items of MOSS spectroscopy, then follows MOSS camera with an emphasis on the optical system of 2D imaging. (author)

MOSS spectroscopic camera for imaging time resolved plasma species temperature and flow speed

Energy Technology Data Exchange (ETDEWEB)

Michael, Clive; Howard, John [Australian National Univ., Plasma Research Laboratory, Canberra (Australia)

2000-03-01

A MOSS (Modulated Optical Solid-State) spectroscopic camera has been devised to monitor the spatial and temporal variations of temperatures and flow speeds of plasma ion species, the Doppler broadening measurement being made of spectroscopic lines specified. As opposed to a single channel MOSS spectrometer, the camera images light from plasma onto an array of light detectors, being mentioned 2D imaging of plasma ion temperatures and flow speeds. In addition, compared to a conventional grating spectrometer, the MOSS camera shows an excellent light collecting performance which leads to the improvement of signal to noise ratio and of time resolution. The present paper first describes basic items of MOSS spectroscopy, then follows MOSS camera with an emphasis on the optical system of 2D imaging. (author)

Physico-Chemical and In-vitro Microbial Studies of Newly Synthesis Organometallic Complexes

Directory of Open Access Journals (Sweden)

Isam Hussain Al-Karkhi

2014-05-01

Full Text Available Drugs normally synthesized to use as medication to treat diseases like cancer and microbial infections, these synthesized drugs were interested more than naturally-derived drugs which have been shows low activity or not as efficient against diseases. A new ligand 3-methylbenzyl (2Z-2-[1-(pyridin-4-ylethylidene]hydrazine carbodithioate (PE3MBC and its Cd(II, Cu(II, Co(II and Zn(II metal complexes. The new ligand and metal complexes were characterized via various physico-chemical and spectroscopic techniques. Cd(II complex show more activity against microbes and against cancer cell line MCF-7, while other complexes does not shows activity like cadmium complex, all the complexes does not shows any activity against MDAMB-231 cell line. The fatal of the cancer and the microbes cell was due to inhibition of DNA synthesis which was probably due to chelating with metals complexes, or could be referred to lipophilicity, presence of hydrophobic moiety in the complex molecule, also could be due to steric effects and electronic effects.

Au36(SePh)24 nanomolecules: synthesis, optical spectroscopy and theoretical analysis.

Science.gov (United States)

Rambukwella, Milan; Chang, Le; Ravishanker, Anish; Fortunelli, Alessandro; Stener, Mauro; Dass, Amala

2018-05-16

Here, we report the synthesis of selenophenol (HSePh) protected Au36(SePh)24 nanomolecules via a ligand-exchange reaction of 4-tert-butylbenzenethiol (HSPh-tBu) protected Au36(SPh-tBu)24 with selenophenol, and its spectroscopic and theoretical analysis. Matrix assisted laser desorption ionization (MALDI) mass spectrometry, electrospray ionization (ESI) mass spectrometry and optical characterization confirm that the composition of the as synthesized product is predominantly Au36(SePh)24 nanomolecules. Size exclusion chromatography (SEC) was employed to isolate the Au36(SePh)24 and temperature dependent optical absorption studies and theoretical analysis were performed. Theoretically, an Independent Component Maps of Oscillator Strength (ICM-OS) analysis of simulated spectra shows that the enhancement in absorption intensity in Au36(SePh)24 with respect to Au36(SPh)24 can be ascribed to the absence of interference and/or increased long-range coupling between interband metal core and ligand excitations. This work demonstrates and helps to understand the effect of Au-Se bridging on the properties of gold nanomolecules.

3D-Mössbauer spectroscopic microscope for mc-Si solar cell evaluation

Energy Technology Data Exchange (ETDEWEB)

Ino, Y., E-mail: y-ino@ob.sist.ac.jp; Soejima, H.; Hayakawa, K.; Yukihira, K.; Tanaka, K.; Fujita, H.; Watanabe, T. [Shizuoka Institute of Science and Technology (Japan); Ogai, K.; Moriguchi, K.; Harada, Y. [APCO. Ltd. (Japan); Yoshida, Y. [Shizuoka Institute of Science and Technology (Japan)

2016-12-15

A 3D-Mössbauer Spectroscopic Microscope is developed to evaluate Fe impurities in multi-crystalline Si solar cells, which combines the Mössbauer spectroscopic microscope with a scanning electron microscope (SEM), an electron beam induced current (EBIC), an electron backscatter diffraction (EBSD), and an electron energy analyzer (HV-CSA). In addition, a new moving-coil-actuator with a liner encoder of 100 nm-resolution is incorporated for the operations with both a constant velocity and a constant acceleration mode successfully with the same precision as that obtained by the conventional transducers. Furthermore, a new multi-capillary X-ray lens is designed to achieve a γ-ray spot size less than 100 μm in diameter. The new microscope provides us to investigate the space correlation between Fe impurities and the lattice defects such as grain boundaries in multi-crystalline Si solar cells.

Spectroscopic Analyses of the Biofuels-Critical Phytochemical Coniferyl Alcohol and Its Enzyme-Catalyzed Oxidation Products

Energy Technology Data Exchange (ETDEWEB)

Achyuthan, Komandoor; Adams, Paul; Simmons, Blake; Singh, Anup

2011-07-13

Lignin composition (monolignol types of coniferyl, sinapyl or p-coumaryl alcohol) is causally related to biomass recalcitrance. We describe multiwavelength (220, 228, 240, 250, 260, 290, 295, 300, 310 or 320 nm) absorption spectroscopy of coniferyl alcohol and its laccase- or peroxidase-catalyzed products during real time kinetic, pseudo-kinetic and endpoint analyses, in optical turn on or turn off modes, under acidic or basic conditions. Reactions in microwell plates and 100 mu L volumes demonstrated assay miniaturization and high throughput screening capabilities. Bathochromic and hypsochromic shifts along with hyperchromicity or hypochromicity accompanied enzymatic oxidations by laccase or peroxidase. The limits of detection and quantitation of coniferyl alcohol averaged 2.4 and 7.1 mu M respectively, with linear trend lines over 3 to 4 orders of magnitude. Coniferyl alcohol oxidation was evident within 10 minutes or with 0.01 mu g/mL laccase and 2 minutes or 0.001 mu g/mL peroxidase. Detection limit improved to 1.0 mu M coniferyl alcohol with Km of 978.7 +/- 150.7 mu M when examined at 260 nm following 30 minutes oxidation with 1.0 mu g/mL laccase. Our assays utilized the intrinsic spectroscopic properties of coniferyl alcohol or its oxidation products for enabling detection, without requiring chemical synthesis or modification of the substrate or product(s). These studies facilitate lignin compositional analyses and augment pretreatment strategies for reducing biomass recalcitrance.

Massive Young Stellar Objects in the Galactic Center. 1; Spectroscopic Identification from Spitzer/IRS Observations

Science.gov (United States)

An, Deokkeun; Ramirez, Solange V.; Sellgren, Kris; Arendt, Richard G.; Boogert, A. C. Adwin; Robitaille, Thomas P.; Schultheis, Mathias; Cotera, Angela S.; Smith, Howard A.; Stolovy, Susan R.

2011-01-01

We present results from our spectroscopic study, using the Infrared Spectrograph (IRS) onboard the Spitzer Space Telescope, designed to identify massive young stellar objects (YSOs) in the Galactic Center (GC). Our sample of 107 YSO candidates was selected based on IRAC colors from the high spatial resolution, high sensitivity Spitzer/IRAC images in the Central Molecular Zone (CMZ), which spans the central approximately 300 pc region of the Milky Way Galaxy. We obtained IRS spectra over 5 micron to 35 micron using both high- and low-resolution IRS modules. We spectroscopically identify massive YSOs by the presence of a 15.4 micron shoulder on the absorption profile of 15 micron CO2 ice, suggestive of CO2 ice mixed with CH30H ice on grains. This 15.4 micron shoulder is clearly observed in 16 sources and possibly observed in an additional 19 sources. We show that 9 massive YSOs also reveal molecular gas-phase absorption from C02, C2H2, and/or HCN, which traces warm and dense gas in YSOs. Our results provide the first spectroscopic census of the massive YSO population in the GC. We fit YSO models to the observed spectral energy distributions and find YSO masses of 8 - 23 solar Mass, which generally agree with the masses derived from observed radio continuum emission. We find that about 50% of photometrically identified YSOs are confirmed with our spectroscopic study. This implies a preliminary star formation rate of approximately 0.07 solar mass/yr at the GC.

The Initial Mass Function in the Nearest Strong Lenses from SNELLS: Assessing the Consistency of Lensing, Dynamical, and Spectroscopic Constraints

Energy Technology Data Exchange (ETDEWEB)

Newman, Andrew B. [The Observatories of the Carnegie Institution for Science, Pasadena, CA (United States); Smith, Russell J. [Centre for Extragalactic Astronomy, University of Durham, South Road, Durham (United Kingdom); Conroy, Charlie [Department of Astronomy, Harvard University, Cambridge, MA (United States); Villaume, Alexa [Department of Astronomy and Astrophysics, University of California, Santa Cruz, CA (United States); Van Dokkum, Pieter, E-mail: anewman@obs.carnegiescience.edu [Department of Astrophysical Sciences, Yale University, New Haven, CT (United States)

2017-08-20

We present new observations of the three nearest early-type galaxy (ETG) strong lenses discovered in the SINFONI Nearby Elliptical Lens Locator Survey (SNELLS). Based on their lensing masses, these ETGs were inferred to have a stellar initial mass function (IMF) consistent with that of the Milky Way, not the bottom-heavy IMF that has been reported as typical for high- σ ETGs based on lensing, dynamical, and stellar population synthesis techniques. We use these unique systems to test the consistency of IMF estimates derived from different methods. We first estimate the stellar M {sub *}/ L using lensing and stellar dynamics. We then fit high-quality optical spectra of the lenses using an updated version of the stellar population synthesis models developed by Conroy and van Dokkum. When examined individually, we find good agreement among these methods for one galaxy. The other two galaxies show 2–3 σ tension with lensing estimates, depending on the dark matter contribution, when considering IMFs that extend to 0.08 M {sub ⊙}. Allowing a variable low-mass cutoff or a nonparametric form of the IMF reduces the tension among the IMF estimates to <2 σ . There is moderate evidence for a reduced number of low-mass stars in the SNELLS spectra, but no such evidence in a composite spectrum of matched- σ ETGs drawn from the SDSS. Such variation in the form of the IMF at low stellar masses ( m ≲ 0.3 M {sub ⊙}), if present, could reconcile lensing/dynamical and spectroscopic IMF estimates for the SNELLS lenses and account for their lighter M {sub *}/ L relative to the mean matched- σ ETG. We provide the spectra used in this study to facilitate future comparisons.

Journal of Chemical Sciences | Indian Academy of Sciences

Indian Academy of Sciences (India)

Synthesis of new series of 4, 5-dihydroisoxazole-5-carboxylate derivatives for the study of their liquid crystalline properties · SUMANA Y KOTIAN NARAYANA U KUDVA .... pp 1113-1118 Regular Article. Tridentate Schiff base (ONO) transition metal complexes: Synthesis, crystal structure, spectroscopic and larvicidal studies.

X-ray polarimetry with the Polarization Spectroscopic Telescope Array (PolSTAR)

DEFF Research Database (Denmark)

Krawczynski, Henric S.; Stern, Daniel; Harrison, Fiona A.

2016-01-01

This paper describes the Polarization Spectroscopic Telescope Array (PolSTAR), a mission proposed to NASA's 2014 Small Explorer (SMEX) announcement of opportunity. PolSTAR measures the linear polarization of 3-50 keV (requirement; goal: 2.5-70 keV) X-rays probing the behavior of matter,radiation ...

Metabolite ratios in 1H MR spectroscopic imaging of the prostate

NARCIS (Netherlands)

Kobus, T.; Wright, A.J.; Weiland, E.; Heerschap, A.; Scheenen, T.W.J.

2015-01-01

In (1)H MR spectroscopic imaging ((1)H-MRSI) of the prostate the spatial distribution of the signal levels of the metabolites choline, creatine, polyamines, and citrate are assessed. The ratio of choline (plus spermine as the main polyamine) plus creatine over citrate [(Cho+(Spm+)Cr)/Cit] is derived

Synthesis of some fenchyl-substituted alkenes and enol-ethers containing 3-oxyphenyl substituents by the Barton-Kellogg reaction

International Nuclear Information System (INIS)

Ciscato, Luiz Francisco M.L.; Bartoloni, Fernando H.; Baader, Wilhelm Josef; Bastos, Erick L.; Guenther, Wolfgang; Weiss, Dieter; Beckert, Rainer

2010-01-01

The synthesis of one fenchyl-substituted alkene and two enol-ethers, containing 3-oxyphenyl substituents by the Barton-Kellogg reaction is described. The tri-substituted aromatic fenchylalkene 1a was prepared in 53% yield from thiofenchone and a diazoanisole; whereas enol-ethers 1b and 1c were obtained (95 and 75% yield, respectively) using an inverse approach based on diazofenchone and aromatic thionoesters. A mixture of Z and E isomers was obtained in all cases; isomer attribution and quantification has been carried out by analysis of NMR spectroscopic data assisted by theoretical calculations (E/Z ratio: 1a = 0.72, 1b = 2.2, 1c = 1.8). Reaction proceeds with low stereoselectivity leading to the preferential formation of diastereoisomeric olefins and enol-ethers where the aromatic substituent resides at the side of the two fenchyl methyl groups. (author)

Synthesis of some fenchyl-substituted alkenes and enol-ethers containing 3-oxyphenyl substituents by the Barton-Kellogg reaction

Energy Technology Data Exchange (ETDEWEB)

Ciscato, Luiz Francisco M.L.; Bartoloni, Fernando H.; Baader, Wilhelm Josef, E-mail: wjbaader@iq.usp.b [Universidade de Sao Paulo (USP), SP (Brazil). Inst. de Quimica. Dept. de Quimica Fundamental; Bastos, Erick L. [Universidade Federal do ABC (UFABC), Santo Andre, SP (Brazil). Centro de Ciencias Naturais e Humanas; Guenther, Wolfgang; Weiss, Dieter; Beckert, Rainer [Friedrich-Schiller Universitaet Jena (Germany). Institut fuer Organische Chemie und Makromolekulare Chemie

2010-07-01

The synthesis of one fenchyl-substituted alkene and two enol-ethers, containing 3-oxyphenyl substituents by the Barton-Kellogg reaction is described. The tri-substituted aromatic fenchylalkene 1a was prepared in 53% yield from thiofenchone and a diazoanisole; whereas enol-ethers 1b and 1c were obtained (95 and 75% yield, respectively) using an inverse approach based on diazofenchone and aromatic thionoesters. A mixture of Z and E isomers was obtained in all cases; isomer attribution and quantification has been carried out by analysis of NMR spectroscopic data assisted by theoretical calculations (E/Z ratio: 1a = 0.72, 1b = 2.2, 1c = 1.8). Reaction proceeds with low stereoselectivity leading to the preferential formation of diastereoisomeric olefins and enol-ethers where the aromatic substituent resides at the side of the two fenchyl methyl groups. (author)

Distributed PROMPT-LTL Synthesis

Directory of Open Access Journals (Sweden)

Swen Jacobs

2016-09-01

Full Text Available We consider the synthesis of distributed implementations for specifications in Prompt Linear Temporal Logic (PROMPT-LTL, which extends LTL by temporal operators equipped with parameters that bound their scope. For single process synthesis it is well-established that such parametric extensions do not increase worst-case complexities. For synchronous systems, we show that, despite being more powerful, the distributed realizability problem for PROMPT-LTL is not harder than its LTL counterpart. For asynchronous systems we have to consider an assume-guarantee synthesis problem, as we have to express scheduling assumptions. As asynchronous distributed synthesis is already undecidable for LTL, we give a semi-decision procedure for the PROMPT-LTL assume-guarantee synthesis problem based on bounded synthesis.

Organic synthesis

International Nuclear Information System (INIS)

Lallemand, J.Y.; Fetizon, M.

1988-01-01

The 1988 progress report of the Organic Synthesis Chemistry laboratory (Polytechnic School, France), is presented. The laboratory activities are centered on the chemistry of natural products, which have a biological activity and on the development of new reactions, useful in the organic synthesis. The research works involve the following domains: the natural products chemistry which are applied in pharmacology, the plants and insects chemistry, the organic synthesis, the radical chemistry new reactions and the bio-organic physicochemistry. The published papers, the congress communications and the thesis are listed [fr

Incorporating spectroscopic on-line monitoring as a method of detection for a Lewis cell setup

Energy Technology Data Exchange (ETDEWEB)

Heller, Forrest D.; Casella, Amanda J.; Lumetta, Gregg J.; Nash, Kenneth L.; Sinkov, Sergey I.; Bryan, Samuel A.

2017-01-01

A Lewis cell was designed and constructed for investigating solvent extraction systems by spectrophotometrically monitoring both the organic and aqueous phases in real time. This new Lewis cell was tested and shown to perform well compared to other previously reported Lewis cell designs. The advantage of the new design is that the spectroscopic measurement allows determination of not only metal ion concentrations, but also information regarding chemical speciation—information not available with previous Lewis cell designs. For convenience, the new Lewis cell design was dubbed COSMOFLEX (COntinuous Spectroscopic MOnitoring of Forrest’s Liquid-liquid EXtraction cell).

Synthesis and spectroscopic behavior of highly luminescent Eu 3+-dibenzoylmethanate (DBM) complexes with sulfoxide ligands

Science.gov (United States)

Niyama, E.; Brito, H. F.; Cremona, M.; Teotonio, E. E. S.; Reyes, R.; Brito, G. E. S.; Felinto, M. C. F. C.

2005-09-01

In this paper the synthesis, characterization and photoluminescent behavior of the [RE(DBM) 3L 2] complexes (RE = Gd and Eu) with a variety of sulfoxide ligands; L = benzyl sulfoxide (DBSO), methyl sulfoxide (DMSO), phenyl sulfoxide (DPSO) and p-tolyl sulfoxide (PTSO) have been investigated in solid state. The emission spectra of the Eu 3+-β-diketonate complexes show characteristics narrow bands arising from the 5D 0 → 7F J ( J = 0-4) transitions, which are split according to the selection rule for C n, C nv or C s site symmetries. The experimental Judd-Ofelt intensity parameters ( Ω2 and Ω4), radiative ( Arad) and non-radiative ( Anrad) decay rates, and R02 for the europium complexes have been determined and compared. The highest value of Ω2 (61.9 × 10 -20 cm 2) was obtained to the complex with PTSO ligand, indicating that Eu 3+ ion is in the highly polarizable chemical environment. The higher values of the experimental quantum yield ( q) and emission quantum efficiency of the emitter 5D 0 level ( η) for the Eu-complexes with DMSO, DBSO and PTSO sulfoxides suggest that these complexes are promising Light Conversion Molecular Devices (LCMDs). The lower value of quantum yield ( q = 1%), for the hydrated complex [Eu(DBM) 3(H 2O)], indicates that the luminescence quenching occurs via multiphonon relaxation by coupling with the OH-oscillators from water molecule coordinated to rare earth ion. The pure red emission of the Eu-complexes has been confirmed by ( x, y) color coordinates.

Dunham spectroscopic constants for the ground and excited states of H2+

International Nuclear Information System (INIS)

Murai, Tomokazu

1975-01-01

The Dunham spectroscopic constants for 12 of the electronic states of H 2 + are computed theoretically from the adiabatic potentials, which are calculated by the author based on the method presented by Bates et al. in the Born-Oppenheimer approximation. (author)

Coronavirus minus-strand RNA synthesis and effect of cycloheximide on coronavirus RNA synthesis

International Nuclear Information System (INIS)

Sawicki, S.G.; Sawicki, D.L.

1986-01-01

The temporal sequence of coronavirus plus-strand and minus-strand RNA synthesis was determined in 17CL1 cells infected with the A59 strain of mouse hepatitis virus (MHV). MHV-induced fusion was prevented by keeping the pH of the medium below pH 6.8. This had no effect on the MHV replication cycle, but gave 5- to 10-fold-greater titers of infectious virus and delayed the detachment of cells from the monolayer which permitted viral RNA synthesis to be studied conveniently until at least 10 h postinfection. Seven species of poly(A)-containing viral RNAs were synthesized at early and late times infection, in nonequal but constant ratios. MHV minus-strand RNA synthesis was first detected at about 3 h after infection and was found exclusively in the viral replicative intermediates and was not detected in 60S single-stranded form in infected cells. Early in the replication cycle, from 45 to 65% of the [ 3 H]uridine pulse-labeled RF core of purified MHV replicative intermediates was in minus-strand RNA. The rate of minus-strand synthesis peaked at 5 to 6 h postinfection and then declined to about 20% of the maximum rate. The addition of cycloheximide before 3 h postinfection prevented viral RNA synthesis, whereas the addition of cycloheximide after viral RNA synthesis had begun resulted in the inhibition of viral RNA synthesis. The synthesis of both genome and subgenomic mRNAs and of viral minus strands required continued protein synthesis, and minis-strand RNA synthesis was three- to fourfold more sensitive to inhibition of cycloheximide than was plus-strand synthesis

THE FIRST SPECTROSCOPICALLY RESOLVED SUB-PARSEC ORBIT OF A SUPERMASSIVE BINARY BLACK HOLE

Energy Technology Data Exchange (ETDEWEB)

Bon, E.; Jovanovic, P.; Bon, N.; Popovic, L. C. [Astronomical Observatory, Volgina 7, 11060 Belgrade (Serbia); Marziani, P. [INAF, Osservatorio Astronomico di Padova, Padova (Italy); Shapovalova, A. I. [Special Astrophysical Observatory of the Russian AS, Nizhnij Arkhyz, Karachaevo-Cherkesia 369167 (Russian Federation); Borka Jovanovic, V.; Borka, D. [Isaac Newton Institute of Chile, Yugoslavia Branch, Belgrade (Serbia); Sulentic, J. [Instituto de Astrofisica de Andalucia, CSIC, Apdo. 3004, E-18080 Granada (Spain)

2012-11-10

One of the most intriguing scenarios proposed to explain how active galactic nuclei are triggered involves the existence of a supermassive binary black hole (BH) system in their cores. Here, we present an observational evidence for the first spectroscopically resolved sub-parsec orbit of a such system in the core of Seyfert galaxy NGC 4151. Using a method similar to those typically used for spectroscopic binary stars, we obtained radial velocity curves of the supermassive binary system, from which we calculated orbital elements and made estimates about the masses of the components. Our analysis shows that periodic variations in the light and radial velocity curves can be accounted for by an eccentric, sub-parsec Keplerian orbit with a 15.9 year period. The flux maximum in the light curve corresponds to the approaching phase of the secondary component toward the observer. According to the obtained results, we speculate that the periodic variations in the observed H{alpha} line shape and flux are due to shock waves generated by the supersonic motion of the components through the surrounding medium. Given the large observational effort needed to reveal this spectroscopically resolved binary orbital motion, we suggest that many such systems may exist in similar objects even if they are hard to find. Detecting more of them will provide us with insight into the BH mass growth process.

THE FIRST SPECTROSCOPICALLY RESOLVED SUB-PARSEC ORBIT OF A SUPERMASSIVE BINARY BLACK HOLE

International Nuclear Information System (INIS)

Bon, E.; Jovanović, P.; Bon, N.; Popović, L. Č.; Marziani, P.; Shapovalova, A. I.; Borka Jovanović, V.; Borka, D.; Sulentic, J.

2012-01-01

One of the most intriguing scenarios proposed to explain how active galactic nuclei are triggered involves the existence of a supermassive binary black hole (BH) system in their cores. Here, we present an observational evidence for the first spectroscopically resolved sub-parsec orbit of a such system in the core of Seyfert galaxy NGC 4151. Using a method similar to those typically used for spectroscopic binary stars, we obtained radial velocity curves of the supermassive binary system, from which we calculated orbital elements and made estimates about the masses of the components. Our analysis shows that periodic variations in the light and radial velocity curves can be accounted for by an eccentric, sub-parsec Keplerian orbit with a 15.9 year period. The flux maximum in the light curve corresponds to the approaching phase of the secondary component toward the observer. According to the obtained results, we speculate that the periodic variations in the observed Hα line shape and flux are due to shock waves generated by the supersonic motion of the components through the surrounding medium. Given the large observational effort needed to reveal this spectroscopically resolved binary orbital motion, we suggest that many such systems may exist in similar objects even if they are hard to find. Detecting more of them will provide us with insight into the BH mass growth process.

The Gaia-ESO Survey: double-, triple-, and quadruple-line spectroscopic binary candidates

Science.gov (United States)

Merle, T.; Van Eck, S.; Jorissen, A.; Van der Swaelmen, M.; Masseron, T.; Zwitter, T.; Hatzidimitriou, D.; Klutsch, A.; Pourbaix, D.; Blomme, R.; Worley, C. C.; Sacco, G.; Lewis, J.; Abia, C.; Traven, G.; Sordo, R.; Bragaglia, A.; Smiljanic, R.; Pancino, E.; Damiani, F.; Hourihane, A.; Gilmore, G.; Randich, S.; Koposov, S.; Casey, A.; Morbidelli, L.; Franciosini, E.; Magrini, L.; Jofre, P.; Costado, M. T.; Jeffries, R. D.; Bergemann, M.; Lanzafame, A. C.; Bayo, A.; Carraro, G.; Flaccomio, E.; Monaco, L.; Zaggia, S.

2017-12-01

Context. The Gaia-ESO Survey (GES) is a large spectroscopic survey that provides a unique opportunity to study the distribution of spectroscopic multiple systems among different populations of the Galaxy. Aims: Our aim is to detect binarity/multiplicity for stars targeted by the GES from the analysis of the cross-correlation functions (CCFs) of the GES spectra with spectral templates. Methods: We developed a method based on the computation of the CCF successive derivatives to detect multiple peaks and determine their radial velocities, even when the peaks are strongly blended. The parameters of the detection of extrema (DOE) code have been optimized for each GES GIRAFFE and UVES setup to maximize detection. The DOE code therefore allows to automatically detect multiple line spectroscopic binaries (SBn, n ≥ 2). Results: We apply this method on the fourth GES internal data release and detect 354 SBn candidates (342 SB2, 11 SB3, and even one SB4), including only nine SBs known in the literature. This implies that about 98% of these SBn candidates are new because of their faint visual magnitude that can reach V = 19. Visual inspection of the SBn candidate spectra reveals that the most probable candidates have indeed a composite spectrum. Among the SB2 candidates, an orbital solution could be computed for two previously unknown binaries: CNAME 06404608+0949173 (known as V642 Mon) in NGC 2264 and CNAME 19013257-0027338 in Berkeley 81 (Be 81). A detailed analysis of the unique SB4 (four peaks in the CCF) reveals that CNAME 08414659-5303449 (HD 74438) in the open cluster IC 2391 is a physically bound stellar quadruple system. The SB candidates belonging to stellar clusters are reviewed in detail to discard false detections. We suggest that atmospheric parameters should not be used for these system components; SB-specific pipelines should be used instead. Conclusions: Our implementation of an automatic detection of spectroscopic binaries within the GES has allowed the

Synthesis and characterization of a new composite based on copper (II) and octa (aminopropil)silsesquioxane

International Nuclear Information System (INIS)

Magossi, M.S. de; Carmo, D.R. do

2014-01-01

In this work, a new compound based silsesquioxane and nitroprusside of copper was prepared starting from octa (aminopropyl)silsesquioxane following a new route of synthesis. The composite prepared as described ACCuN was preliminarily characterized by spectroscopic techniques, such as Infrared Spectroscopy in the Region of the Fourier transform (FTIR), Energy Dispersive X-ray (EDX), Scanning Electron Microscopy (SEM) and cyclic voltammetry (VC). The FTIR spectra showed absorption bands at 1106 cm"-"1 due to stretching Si-O-Si_(_ν_S_i_-_O_-_S_i_) characteristic of the structure of octa(aminopropylsilsesquioxane and absorption bands at 2063 cm"-"1 ascribed to the stretching NO_(_ν_N_-_O) and 2192 cm"-"1 attributed to the stretching C≡N_(_ν_≡N_). SEM and EDX observed cluster of cubic particles with an average size of approximately 241 nm, containing Si, O, N, Cu and Fe. Cyclic voltammogram of the material (ACCuN) showed a redox couple with average potential Eθ '= 0.73 V. (author)

Synthesis and characterisation of new Schiff base monomers containing N-(alkyl and phenyl) pyrrole moieties

Science.gov (United States)

Amer, Ahcene Ait; Ilikti, Hocine; Maschke, Ulrich

2017-11-01

This article deals with the synthesis and characterisation of seven new functional Schiff base monomers, such as: M1: 1-(3-Pyrrole-1-yl-propylimino-methyl)-naphtalen-2-ol; M2: 2-(3-Pyrrole-1-yl-phenylimino-methyl)-phenol; M3: 1-(3-Pyrrole-1-yl-phenylimino-methyl)-naphtalen-2-ol; M4: N-(pyridin-2-yl-methylene)-2-(pyrrol-1-yl)-benzenamine; M5: N-(pyridin-2-yl-methylene)-3-(pyrrol-1-yl)-propan-1-amine; M6: 2-(3-pyrrol-1-yl-propylimino-methyl)-quinolin-8-ol; M7: 2-(3-pyrrol-1-yl-phenylimino-methyl)-quinolin-8-ol. Two series of compounds emerged from this study, N-propyl pyrrole derivatives (M1, M5, M6) and N-phenyl pyrrole compounds (M2, M3, M4, M7). All monomers were elaborated by condensation reactions between appropriate amines and aldehydes, and their molecular structures were confirmed by spectroscopic analysis methods like FT-IR, 1H NMR, 13C NMR, and GC-MS.

Synthesis, physico-chemical properties and complexing abilities of new amphiphilic ligands from D-galacturonic acid.

Science.gov (United States)

Allam, Anas; Behr, Jean-Bernard; Dupont, Laurent; Nardello-Rataj, Véronique; Plantier-Royon, Richard

2010-04-19

This paper describes a convenient and efficient synthesis of new complexing surfactants from d-galacturonic acid and n-octanol as renewable raw materials in a two-step sequence. In the first step, simultaneous O-glycosidation-esterification under Fischer conditions was achieved. The anomeric ratio of the products was studied based on the main experimental parameters and the activation mode (thermal or microwave). In the second step, aminolysis of the n-octyl ester was achieved with various functionalized primary amines under standard thermal or microwave activation. The physico-chemical properties of these new amphiphilic ligands were measured and these compounds were found to exhibit interesting surface properties. Complexing abilities of one uronamide ligand functionalized with a pyridine moiety toward Cu(II) ions was investigated in solution by EPR titrations. A solid compound was also synthesized and characterized, its relative structure was deduced from spectroscopic data. Copyright (c) 2010 Elsevier Ltd. All rights reserved.

Spectroscopic characterization approach to study surfactants effect on ZnO{sub 2} nanoparticles synthesis by laser ablation process

Energy Technology Data Exchange (ETDEWEB)

Drmosh, Q.A. [Laser Research Group, Physics Department, King Fahd University of Petroleum and Minerals, Dhahran 31261 (Saudi Arabia); Center of Excellence in Nanotechnology (CENT), King Fahd University of Petroleum and Minerals, Dhahran 31261 (Saudi Arabia); Gondal, M.A., E-mail: magondal@kfupm.edu.sa [Laser Research Group, Physics Department, King Fahd University of Petroleum and Minerals, Dhahran 31261 (Saudi Arabia); Center of Excellence in Nanotechnology (CENT), King Fahd University of Petroleum and Minerals, Dhahran 31261 (Saudi Arabia); Yamani, Z.H. [Laser Research Group, Physics Department, King Fahd University of Petroleum and Minerals, Dhahran 31261 (Saudi Arabia); Center of Excellence in Nanotechnology (CENT), King Fahd University of Petroleum and Minerals, Dhahran 31261 (Saudi Arabia); Saleh, T.A. [Center of Excellence in Nanotechnology (CENT), King Fahd University of Petroleum and Minerals, Dhahran 31261 (Saudi Arabia); Chemistry Department, King Fahd University of Petroleum and Minerals, Dhahran 31261 (Saudi Arabia)

2010-05-01

Zinc peroxide nanoparticles having grain size less than 5 nm were synthesized using pulsed laser ablation in aqueous solution in the presence of different surfactants and solid zinc target in 3% H{sub 2}O{sub 2}. The effect of surfactants on the optical and structure of ZnO{sub 2} was studied by applying different spectroscopic techniques. Structural properties and grain size of the synthesized nanoparticles were studied using XRD method. The presence of the cubic phase of zinc peroxide in all samples was confirmed with XRD, and the grain sizes were 4.7, 3.7, 3.3 and 2.8 nm in pure H{sub 2}O{sub 2}, and H{sub 2}O{sub 2} mixed with SDS, CTAB and OGM respectively. For optical characterization, FTIR transmittance spectra of ZnO{sub 2} nanoparticles prepared with and without surfactants show a characteristic ZnO{sub 2} absorption at 435-445 cm{sup -1}. FTIR spectrum revealed that the adsorbed surfactants on zinc peroxide disappeared in case of CTAB and OGM while it appears in case of SDS. This could be due to high critical micelles SDS concentration comparing with others which is attributed to the adsorption anionic nature of this surfactant. Both FTIR and UV-vis spectra show a red shift in the presence of SDS and blue shift in the presence of CTAB and OGM. The blue shift in the absorption edge indicates the quantum confinement property of nanoparticles. The zinc peroxide nanoparticles prepared in additives-free media was also characterized by Raman spectra which show the characteristic peaks at 830-840 and 420-440 cm{sup -1}.

Spectroscopic probes of vibrationally excited molecules at chemically significant energies

Energy Technology Data Exchange (ETDEWEB)

Rizzo, T.R. [Univ. of Rochester, NY (United States)

1993-12-01

This project involves the application of multiple-resonance spectroscopic techniques for investigating energy transfer and dissociation dynamics of highly vibrationally excited molecules. Two major goals of this work are: (1) to provide information on potential energy surfaces of combustion related molecules at chemically significant energies, and (2) to test theoretical modes of unimolecular dissociation rates critically via quantum-state resolved measurements.

Phosphorus(V)-corrole: synthesis, spectroscopic properties, theoretical calculations, and potential utility for in vivo applications in living cells.

Science.gov (United States)

Liang, Xu; Mack, John; Zheng, Li-Min; Shen, Zhen; Kobayashi, Nagao

2014-03-17

The synthesis and properties of phosphorus(V) 5,10,15-tris(4-methoxycarbonylphenyl)corrole (1) have been investigated, and its potential utility for bioimaging applications in living cells has been explored. As would normally be anticipated for corrole complexes, the intensity of the Q(0,0) bands of 1 is greater than those of comparable phosphorus(V) tetraphenylporphyrins, but the ΦF values (0.25 for 1) are found to be comparable. A detailed analysis of the electronic structure of the complex was carried out by comparing electronic absorption and MCD spectral data to the results of TD-DFT calculations. The meso-aryl substituents, which enhance the lipophilicity of 1 and hence result in its localization in intracellular membranes during HeLa cell experiments, are predicted to result in a narrowing of the HOMO-LUMO gap and hence a red shift of the Q(0,0) bands toward the optical window in biological tissues.

Ion-beam spectroscopic studies of the 69As nucleus

International Nuclear Information System (INIS)

Badica, T.; Cojocaru, V.; Olariu, A.; Petre, M.; Popescu, I. V.; Gheboianu, A.

2009-01-01

Excited state of the neutron deficient 69 As nucleus were investigated in the 58 Ni( 14 N,2pn) reaction by ion-beam γ spectroscopic methods (excitation functions, γγ-coincidences, angular distributions and linear polarization gated with neutrons). A new more complete level scheme of 69 As has been proposed with spin-parity values. The structure of the nucleus is discussed in the framework of the interaction boson-fermion model (IBFM). (authors)

Synthesis of rearranged unsaturated drimane derivatives

Directory of Open Access Journals (Sweden)

Miranda Domingos S. de

2001-01-01

Full Text Available A full account to the preparation and application of three appropriately substituted vinylcyclohexenes (2,2-dimethyl-3-vinylcyclohex-3-en-1-ol, 2,2-dimethyl-3-vinylcyclohex-3-en-1-one and 3,3-dimethyl-2-vinylcyclohexene in thermal Diels-Alder reactions with alpha,beta-unsaturated esters (methyl tiglate and methyl angelate is given. This approach delivered the racemic synthesis of ten octalin derivatives bearing a rearranged drimane skeleton (4 diastereomers of 1-methoxycarbonyl-6-hydroxy-1,2,5,5-tetramethyl-1,2,3,5,6,7, 8,8a-octahydronaphthalene; 1-methoxycarbonyl-6-oxo-1,2,5,5-tetramethyl-1,2,3,4,5,6,7,8-octahydronaphthalene; 2-methoxycarbonyl-6-oxo-1,2,5,5-tetramethyl-1,2,3,5,6,7,8,8a-octahydronaphthalene; 3 diastereomers of 1-methoxycarbonyl-1,2,5,5-tetramethyl-1,2,3,5,6,7,8,8a-octahydronaphthalene and 2-methoxycarbonyl-1,2,5,5-tetramethyl-1,2,3,5,6,7,8,8a-octahydronaphthalene . Central synthetic features included preparation of enoltriflates by Stang's protocol and the successful palladium-catalyzed cross-coupling reaction (Stille reaction of the triflate with the tri-n-butylvinylstannane. The octalins relative stereochemistry was unequivocally ascertained by spectroscopic methods and/or X-ray crystallography and these data now stand as useful tools to support the correct assignment of related natural products usually isolated in minute amounts.

Grading of cerebral gilomas: correlation with perfusion MRI, spectroscopic MRI and histopathology

International Nuclear Information System (INIS)

Law, M.; Cha, S.; Knopp, E.A.; Johnson, G.; Litt, A.W.

2002-01-01

Full text: The aim of this study was to determine the correlation between perfusion MRI (pMRI), spectroscopic MRI (sMRI) and histopathologic grading of primary glial neoplasms. Echo-planar pMRI has already been shown to be a robust physiological tool in preoperatively predicting tumor grade and guiding stereotactic biopsy (1). Thirty-four patients with a primary glial neoplasm underwent conventional MR imaging, T2*-weighted echo planar pMRI and sMRI. Four rCBV measurements were obtained from the colour maps of each lesion to determine the maximum rCBV. Spectroscopic MRI utilizing 2D chemical shift imaging at a TE of 135 provided multi-voxel spectroscopic data in sixteen of these patients. The maximum Cho/NAA, Cho/Cr, and minimum NAA/Cr ratios were obtained as well as documenting the presence of lactate and lipids. This was compared with the histopathological grading (including staining with H and E, GFAP, vimentin and MIB1, proliferative index) obtained from volumetric resection or stereotactic biopsy. The maximum rCBV in high grade tumors (n=26) ranged from 1.34 to 5.15, with a mean of 3.00 ± 1.21 (SD), and in the low grade tumors (n=8) ranged from 1.47 to 2.49, with a mean of 1.81 ± 1.21 (SD).This difference was statistically significant (p<0.001; Student t test). Maximum values for Cho/NAA, Cho/Cr and minimum NAA/Cr values were 3.24 ± 3.26, 2.49 ± 1.17 and 1.02 ± 0.34, respectively in the high grade (n = 11), and 1.3 ± 0.39, 1.58 ± 0.45 and 0.89 ± 0.37 respectively in the low-grade tumors (n = 5). A statistically significant difference was found for the Cho/Cr ratio (p<0.05) between the high grade and low grade groups. Relative CBV measurements and spectroscopic metabolic ratios are complementary and correlate with histopathology (2,3). These tools provide powerful physiological and metabolic information for preoperative prediction of tumor grade and will guide pre and post operative planning and management. Copyright (2002) Blackwell Science Pty Ltd

An Approach to Interface Synthesis

DEFF Research Database (Denmark)

Madsen, Jan; Hald, Bjarne

1995-01-01

Presents a novel interface synthesis approach based on a one-sided interface description. Whereas most other approaches consider interface synthesis as optimizing a channel to existing client/server modules, we consider the interface synthesis as part of the client/server module synthesis (which...... may contain the re-use of existing modules). The interface synthesis approach describes the basic transformations needed to transform the server interface description into an interface description on the client side of the communication medium. The synthesis approach is illustrated through a point...

Characterization of plasmonic effects in thin films and metamaterials using spectroscopic ellipsometry

NARCIS (Netherlands)

Oates, T.W.H.; Wormeester, Herbert; Arwin, H.

2011-01-01

In this article, spectroscopic ellipsometry studies of plasmon resonances at metal–dielectric interfaces of thin films are reviewed. We show how ellipsometry provides valuable non-invasive amplitude and phase information from which one can determine the effective dielectric functions, and how these

Spectroscopic evidence of hippocampal abnormalities in neocortical epilepsy

Science.gov (United States)

Mueller, S. G.; Laxer, K. D.; Cashdollar, N.; Lopez, R. C.; Weiner, M. W.

2009-01-01

Lesional neocortical epilepsy (NE) can be associated with hippocampal sclerosis or hippocampal spectroscopic abnormalities without atrophy (dual pathology). In this study, magnetic resonance spectroscopic imaging (MRSI) was used to determine the frequency of hippocampal damage/dysfunction in NE with and without structural lesion. Sixteen patients with NE [seven temporal NE (NE-T), nine extratemporal (NE-ET)] and 16 controls were studied with a 2D MRSI sequence (Repetition time/echo time (TR/TE) = 1800/135 ms) covering both hippocampi. Seven NE patients had MR visible lesions (NE-Les), nine had normal MRI (NE-no). In each hippocampus, 12 voxels were uniformly selected. In controls, mean (± SD) NAA/(Cr + Cho) values for each voxel were calculated and voxels with NAA/(Cr + Cho) ≤ (mean in controls – 2SD in controls) were defined as ‘pathological’ in patients. Eight of 16 NE patients had at least two ‘pathological’ voxel (mean 2.5, range 2–5) in one hippocampus. Four were NE-Les and four NE-no. Three (43%) NE-T patients, had evidence for hippocampal damage/dysfunction and five (56%) had NE-ET. The ipsilateral hippocampus was affected in six of eight NE patients. Evidence for unilateral hippocampal damage/dysfunction was demonstrated in 50% of the NE patients. The type of NE, i.e. NE-Les or NE-no, NE-T or NE-ET, had no influence on the occurrence of hippocampal damage/dysfunction. PMID:16618342

Spectroscopic studies of carbon impurities in PISCES-A

International Nuclear Information System (INIS)

Ra, Y.; Hirooka, Y.; Leung, W.K.; Conn, R.W.; Pospieszczyk, A.

1989-08-01

The graphite used for the limiter of the tokamak reactor produces carbon-containing molecular impurities as a result of the interactions with the edge plasma. The behavior of these molecular impurities has been studied using emission spectroscopy. The present study includes: finding molecular bands and atomic lines in the visible spectral range which can be used for the study of the molecular impurities, studying the breakup processes of the molecular impurities on their way from the source into the plasma, developing a spectroscopic diagnostic method for the absolute measurement of the molecular impurity flux resulting from graphite erosion. For these studies, carbon-containing molecules such as CH 4 , C 2 H 2 , C 2 H 4 , and CO 2 were injected into the tokamak-boundary,like plasma generated by PISCES-A. The spectrograms of these gases were taken. Many useful bands and lines were determined from the spectrograms. The breakup processes of these gases were studied by observing the spatial profiles of the emission of the molecules and their radicals for different plasma conditions. For the absolute measurement of the eroded molecular impurity flux, the photon efficiency of the lines and bands were found by measuring the absolute number of the emitted photons and injected gas molecules. The chemical sputtering yield of graphite by hydrogen plasma was spectroscopically measured using the previously obtained photon efficiencies. It showed good agreement with results obtained by weight loss measurements. 16 refs., 7 figs., 1 tab

Spectroscopic studies on novel donor-acceptor and low band-gap polymeric semiconductors

International Nuclear Information System (INIS)

Cravino, A.

2002-11-01

Novel low band-gap conjugated polymeric semiconductors as well as conjugated electron donor chains carrying electron acceptor substituents were electrochemically prepared and investigated by means of different spectroscopic techniques. Using in situ FTIR and ESR spectroelectrochemistry, the spectroscopic features of injected positive charges are found to be different as opposed to the negative charge carriers on the same conjugated polymer. These results, for which the theoretical models so far developed do not account, demonstrate the different structure and delocalization of charge carriers with opposite signs. In addition, vibrational spectroscopy results proof the enhanced 'quinoid' character of low band-gap conjugated chains. Excited state spectroscopy was applied to study photoexcitations in conjugated polymers carrying tetracyanoanthraquinone type or fullerene moieties. This novel class of materials, hereafter called double-cable polymers, was found promising as alternative to the conjugated polymer:fullerene mixtures currently used for the preparation of 'bulk-heterojunction' polymeric solar cells. (author)

RADIAL VELOCITIES OF GALACTIC O-TYPE STARS. II. SINGLE-LINED SPECTROSCOPIC BINARIES

International Nuclear Information System (INIS)

Williams, S. J.; Gies, D. R.; Hillwig, T. C.; McSwain, M. V.; Huang, W.

2013-01-01

We report on new radial velocity measurements of massive stars that are either suspected binaries or lacking prior observations. This is part of a survey to identify and characterize spectroscopic binaries among O-type stars with the goal of comparing the binary fraction of field and runaway stars with those in clusters and associations. We present orbits for HDE 308813, HD 152147, HD 164536, BD–16°4826, and HDE 229232, Galactic O-type stars exhibiting single-lined spectroscopic variation. By fitting model spectra to our observed spectra, we obtain estimates for effective temperature, surface gravity, and rotational velocity. We compute orbital periods and velocity semiamplitudes for each system and note the lack of photometric variation for any system. These binaries probably appear single-lined because the companions are faint and because their orbital Doppler shifts are small compared to the width of the rotationally broadened lines of the primary.

THE BOSS EMISSION-LINE LENS SURVEY (BELLS). I. A LARGE SPECTROSCOPICALLY SELECTED SAMPLE OF LENS GALAXIES AT REDSHIFT {approx}0.5

Energy Technology Data Exchange (ETDEWEB)

Brownstein, Joel R.; Bolton, Adam S.; Pandey, Parul [Department of Physics and Astronomy, University of Utah, Salt Lake City, UT 84112 (United States); Schlegel, David J. [Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States); Eisenstein, Daniel J. [Harvard College Observatory, 60 Garden Street, MS 20, Cambridge, MA 02138 (United States); Kochanek, Christopher S. [Department of Astronomy and Center for Cosmology and Astroparticle Physics, Ohio State University, Columbus, OH 43210 (United States); Connolly, Natalia [Department of Physics, Hamilton College, Clinton, NY 13323 (United States); Maraston, Claudia [Institute of Cosmology and Gravitation, University of Portsmouth, Portsmouth PO1 3FX (United Kingdom); Seitz, Stella [University Observatory Munich, Scheinstrasse 1, 81679 Muenchen (Germany); Wake, David A. [Department of Astronomy, Yale University, New Haven, CT 06520 (United States); Wood-Vasey, W. Michael [Pittsburgh Center for Particle Physics, Astrophysics, and Cosmology (PITT-PACC), Department of Physics and Astronomy, University of Pittsburgh, Pittsburgh, PA 15260 (United States); Brinkmann, Jon [Apache Point Observatory, P.O. Box 59, Sunspot, NM 88349 (United States); Schneider, Donald P. [Department of Astronomy and Astrophysics and Institute for Gravitation and the Cosmos, Pennsylvania State University, University Park, PA 16802 (United States); Weaver, Benjamin A. [Center for Cosmology and Particle Physics, New York University, New York, NY 10003 (United States)

2012-01-01

We present a catalog of 25 definite and 11 probable strong galaxy-galaxy gravitational lens systems with lens redshifts 0.4 {approx}< z {approx}< 0.7, discovered spectroscopically by the presence of higher-redshift emission lines within the Baryon Oscillation Spectroscopic Survey (BOSS) of luminous galaxies, and confirmed with high-resolution Hubble Space Telescope (HST) images of 44 candidates. Our survey extends the methodology of the Sloan Lens Advanced Camera for Surveys survey (SLACS) to higher redshift. We describe the details of the BOSS spectroscopic candidate detections, our HST ACS image processing and analysis methods, and our strong gravitational lens modeling procedure. We report BOSS spectroscopic parameters and ACS photometric parameters for all candidates, and mass-distribution parameters for the best-fit singular isothermal ellipsoid models of definite lenses. Our sample to date was selected using only the first six months of BOSS survey-quality spectroscopic data. The full five-year BOSS database should produce a sample of several hundred strong galaxy-galaxy lenses and in combination with SLACS lenses at lower redshift, strongly constrain the redshift evolution of the structure of elliptical, bulge-dominated galaxies as a function of luminosity, stellar mass, and rest-frame color, thereby providing a powerful test for competing theories of galaxy formation and evolution.

Heterocyclic Analogues of Xanthone and Xanthione. 1H-Pyrano[2,3-c:6,5-c]dipyrazol-4(7H-ones and Thiones: Synthesis and NMR Data

Directory of Open Access Journals (Sweden)

Wolfgang Holzer

2010-09-01

Full Text Available The synthesis of the title compounds is described. Reaction of 1-substituted 2-pyrazolin-5-ones with 5-chloro-1-phenyl-1H-pyrazole-4-carbonyl chloride or 5-chloro-3-methyl-1-phenyl-1H-pyrazole-4-carbonyl chloride, respectively, using calcium hydroxide in refluxing 1,4-dioxane gave the corresponding 4-heteroaroylpyrazol-5-ols, which were cyclized into 1H-pyrano[2,3-c:6,5-c]dipyrazol-4(7H-ones by treatment with K2CO3/DMF. The latter were converted into the corresponding thiones upon reaction with Lawesson’s reagent. Detailed NMR spectroscopic investigations (1H, 13C, 15N of the ring systems and their precursors are presented.

Green Synthesis of Silver Nanoparticles using Achillea biebersteinii Flower Extract and Its Anti-Angiogenic Properties in the Rat Aortic Ring Model

Directory of Open Access Journals (Sweden)

Javad Baharara

2014-04-01

Full Text Available Silver nanoparticles display unique physical and biological properties which have attracted intensive research interest because of their important medical applications. In this study silver nanoparticles (Ab.Ag-NPs were synthesized for biomedical applications using a completely green biosynthetic method using Achillea biebersteinii flowers extract. The structure and properties of Ab.Ag-NPs were investigated using UV-visible spectroscopic techniques, transmission electron microscopy (TEM, zeta potential and energy dispersive X-ray spectrometers (EDS. The UV-visible spectroscopic analysis showed the absorbance peak at 460 nm, which indicates the synthesis of silver nanoparticles. The average particle diameter as determined by TEM was found to be 12 ± 2 nm. The zeta potential analysis indicated that Ab.Ag-NPs have good stability EDX analysis also exhibits presentation of silver element. As angiogenesis is an important phenomenon and as growth factors imbalance in this process causes the acceleration of several diseases including cancer, the anti-angiogenic properties of Ab.Ag-NPs were evaluated using the rat aortic ring model. The results showed that Ab.Ag-NPs (200 μg/mL lead to a 50% reduction in the length and number of vessel-like structures. The synthesized silver nanoparticles from the Achillea biebersteinii flowers extract, which do not involve any harmful chemicals were well-dispersed and stabilized through this green method and showed potential therapeutic benefits against angiogenesis.

Vanadyl complexes with dansyl-labelled di-picolinic acid ligands: synthesis, phosphatase inhibition activity and cellular uptake studies.

Science.gov (United States)

Collins, Juliet; Cilibrizzi, Agostino; Fedorova, Marina; Whyte, Gillian; Mak, Lok Hang; Guterman, Inna; Leatherbarrow, Robin; Woscholski, Rudiger; Vilar, Ramon

2016-04-28

Vanadium complexes have been previously utilised as potent inhibitors of cysteine based phosphatases (CBPs). Herein, we present the synthesis and characterisation of two new fluorescently labelled vanadyl complexes (14 and 15) with bridged di-picolinic acid ligands. These compounds differ significantly from previous vanadyl complexes with phosphatase inhibition properties in that the metal-chelating part is a single tetradentate unit, which should afford greater stability and scope for synthetic elaboration than the earlier complexes. These new complexes inhibit a selection of cysteine based phosphatases (CBPs) in the nM range with some selectivity. Fluorescence spectroscopic studies (including fluorescence anisotropy) were carried out to demonstrate that the complexes are not simply acting as vanadyl delivery vehicles but they interact with the proteins. Finally, we present preliminary fluorescence microscopy studies to demonstrate that the complexes are cell permeable and localise throughout the cytoplasm of NIH3T3 cells.

Systems budgets architecture and development for the Maunakea Spectroscopic Explorer

Science.gov (United States)

Mignot, Shan; Flagey, Nicolas; Szeto, Kei; Murowinski, Rick; McConnachie, Alan

2016-08-01

The Maunakea Spectroscopic Explorer (MSE) project is an enterprise to upgrade the existing Canada-France- Hawaii observatory into a spectroscopic facility based on a 10 meter-class telescope. As such, the project relies on engineering requirements not limited only to its instruments (the low, medium and high resolution spectrographs) but for the whole observatory. The science requirements, the operations concept, the project management and the applicable regulations are the basis from which these requirements are initially derived, yet they do not form hierarchies as each may serve several purposes, that is, pertain to several budgets. Completeness and consistency are hence the main systems engineering challenges for such a large project as MSE. Special attention is devoted to ensuring the traceability of requirements via parametric models, derivation documents, simulations, and finally maintaining KAOS diagrams and a database under IBM Rational DOORS linking them together. This paper will present the architecture of the main budgets under development and the associated processes, expand to highlight those that are interrelated and how the system, as a whole, is then optimized by modelling and analysis of the pertinent system parameters.

CDSD-4000: High-resolution, high-temperature carbon dioxide spectroscopic databank

International Nuclear Information System (INIS)

Tashkun, S.A.; Perevalov, V.I.

2011-01-01

We present a high-resolution, high-temperature version of the Carbon Dioxide Spectroscopic Databank called CDSD-4000. The databank contains the line parameters (positions, intensities, air- and self-broadened half-widths, coefficients of temperature dependence of air- and self-broadened half-widths, and air-broadened pressure shifts) of the four most abundant isotopologues of CO 2 . A reference temperature is 296 K and an intensity cutoff is 10 -27 cm -1 /molecule cm -2 at 4000 K. The databank has 628,324,454 entries, covers the 226-8310 cm -1 spectral range and designed for the temperature range 2500-5000 K. Format of CDSD-4000 is similar to that of HITRAN-2008. The databank has been generated within the framework of the method of effective operators and based on the global fittings of spectroscopic parameters (parameters of the effective Hamiltonians and effective dipole moment operators) to observed data collected from the literature. The databank is useful for studying high-temperature radiative properties of CO 2 , including exoplanets atmospheres, aerothemal modeling for Mars entry missions, high-temperature laboratory spectra, and industrial applications. CDSD-4000 is freely accessible via the Internet site (ftp://ftp.iao.ru/pub/CDSD-4000).

The Large Area Radio Galaxy Evolution Spectroscopic Survey (LARGESS): survey design, data catalogue and GAMA/WiggleZ spectroscopy

Science.gov (United States)

Ching, John H. Y.; Sadler, Elaine M.; Croom, Scott M.; Johnston, Helen M.; Pracy, Michael B.; Couch, Warrick J.; Hopkins, A. M.; Jurek, Russell J.; Pimbblet, K. A.

2017-01-01

We present the Large Area Radio Galaxy Evolution Spectroscopic Survey (LARGESS), a spectroscopic catalogue of radio sources designed to include the full range of radio AGN populations out to redshift z ˜ 0.8. The catalogue covers ˜800 deg2 of sky, and provides optical identifications for 19 179 radio sources from the 1.4 GHz Faint Images of the Radio Sky at Twenty-cm (FIRST) survey down to an optical magnitude limit of Imod point-like objects are included, and no colour cuts are applied. In collaboration with the WiggleZ and Galaxy And Mass Assembly (GAMA) spectroscopic survey teams, we have obtained new spectra for over 5000 objects in the LARGESS sample. Combining these new spectra with data from earlier surveys provides spectroscopic data for 12 329 radio sources in the survey area, of which 10 856 have reliable redshifts. 85 per cent of the LARGESS spectroscopic sample are radio AGN (median redshift z = 0.44), and 15 per cent are nearby star-forming galaxies (median z = 0.08). Low-excitation radio galaxies (LERGs) comprise the majority (83 per cent) of LARGESS radio AGN at z < 0.8, with 12 per cent being high-excitation radio galaxies (HERGs) and 5 per cent radio-loud QSOs. Unlike the more homogeneous LERG and QSO sub-populations, HERGs are a heterogeneous class of objects with relatively blue optical colours and a wide dispersion in mid-infrared colours. This is consistent with a picture in which most HERGs are hosted by galaxies with recent or ongoing star formation as well as a classical accretion disc.

Synthesis and characterization of novel Cu(II) complex coated Fe3O4@SiO2 nanoparticles for catalytic performance

Science.gov (United States)

Nasrollahzadeh, Mahmoud; Sajjadi, Mohaddeseh; Khonakdar, Hossein Ali

2018-06-01

In this study, a convenient method for the synthesis of arylaminotetrazoles has been developed using a copper (II)-aminotetrazole complex immobilized on silica-coated Fe3O4 (Fe3O4@SiO2) nanoparticles (Fe3O4@SiO2-aminotet-Cu(II)) as a novel and efficient magnetically catalyst. The constructed superparamagnetic core-shell nanoparticles were successfully prepared, as proven using different spectroscopic techniques such as fourier-transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), transmission electron microscope (TEM), field emission scanning electron microscopy (FESEM), energy dispersive X-ray spectroscopy (EDS), thermogravimetry and differential thermogravimetry (TG-DTG) and vibrating sample magnetometer (VSM) analysis. The applicability of Fe3O4@SiO2-aminotet-Cu(II) magnetic catalyst allows the efficient synthesis of a variety of arylaminotetrazoles from the reaction between various arylcyanamides with sodium azide in high yields. The effect of catalyst loading was investigated. In addition, the reaction mechanism for the synthesis of arylaminotetrazoles was reasonably proposed. Results show that the 1-aryl-5-amino-1H-tetrazole (B isomer) and 5-arylamino-1H-tetrazole (A isomer) can be obtained from the arylcyanamides carrying electron-donating and electron-withdrawing substituents, respectively. This procedure offers a simple methodology, relatively short reaction times, easy work-up, high yields of the products and a cleaner reaction with elimination of hydrazoic acid (HN3). Moreover, catalyst can be conveniently recovered through the use of external magnet and reused for at least 6 times without any significant loss of its activity.

Moessbauer spectroscopic investigations of Fe/Mn-Fischer-Tropsch-catalysts

International Nuclear Information System (INIS)

Deppe, P.; Papp, H.; Rosenberg, M.

1986-01-01

The phase composition of Fe/Mn oxide catalysts of different compositions after 200 h of Fischer-Tropsch synthesis have been investigated by Moessbauer spectroscopy at room temperature, 77 K and 5 K. The final composition of the bulk catalysts depends strongly on the Mn content and the temperature of reduction before the synthesis. Catalytic activity and selectivity are partly correlated to this phase composition. (Auth.)

Spectroscopic characterization of the ethyl radical-water complex.

Science.gov (United States)

Lin, Chen; Finney, Brian A; Laufer, Allan H; Anglada, Josep M; Francisco, Joseph S

2016-10-14

An ab initio investigation has been employed to determine the structural and spectroscopic parameters, such as rotational constants, vibrational frequencies, vertical excitation energies, and the stability of the ethyl-water complex. The ethyl-water complex has a binding energy of 1.15 kcal⋅mol -1 . The interaction takes place between the hydrogen of water and the unpaired electron of the radical. This interaction is found to produce a red shift in the OH stretching bands of water of ca. 84 cm -1 , and a shift of all UV absorption bands to higher energies.

Dual-probe spectroscopic fingerprints of defects in graphene

DEFF Research Database (Denmark)

Settnes, Mikkel; Power, Stephen; Petersen, Dirch Hjorth

2014-01-01

(e.g., an extended graphene sheet). Applying this method, we study the transport anisotropies in pristine graphene sheets, and analyze the spectroscopic fingerprints arising from quantum interference around single-site defects, such as vacancies and adatoms. Furthermore, we demonstrate that the dual......-probe setup is a useful tool for characterizing the electronic transport properties of extended defects or designed nanostructures. In particular, we show that nanoscale perforations, or antidots, in a graphene sheet display Fano-type resonances with a strong dependence on the edge geometry of the perforation....

The Ninth Data Release of the Sloan Digital Sky Survey: First Spectroscopic Data from the SDSS-III Baryon Oscillation Spectroscopic Survey

Energy Technology Data Exchange (ETDEWEB)

Ahn, Christopher P.; Alexandroff, Rachael; Allende Prieto, Carlos; Anderson, Scott F.; Anderton, Timothy; Andrews, Brett H.; Aubourg, Éric; Bailey, Stephen; Balbinot, Eduardo; Barnes, Rory; Bautista, Julian; Beers, Timothy C.; Beifiori, Alessandra; Berlind, Andreas A.; Bhardwaj, Vaishali; Bizyaev, Dmitry; Blake, Cullen H.; Blanton, Michael R.; Blomqvist, Michael; Bochanski, John J.; Bolton, Adam S.; Borde, Arnaud; Bovy, Jo; Brandt, W. N.; Brinkmann, J.; Brown, Peter J.; Brownstein, Joel R.; Bundy, Kevin; Busca, N. G.; Carithers, William; Carnero, Aurelio R.; Carr, Michael A.; Casetti-Dinescu, Dana I.; Chen, Yanmei; Chiappini, Cristina; Comparat, Johan; Connolly, Natalia; Crepp, Justin R.; Cristiani, Stefano; Croft, Rupert A. C.; Cuesta, Antonio J.; da Costa, Luiz N.; Davenport, James R. A.; Dawson, Kyle S.; de Putter, Roland; De Lee, Nathan; Delubac, Timothée; Dhital, Saurav; Ealet, Anne; Ebelke, Garrett L.; Edmondson, Edward M.; Eisenstein, Daniel J.; Escoffier, S.; Esposito, Massimiliano; Evans, Michael L.; Fan, Xiaohui; Femenía Castellá, Bruno; Fernández Alvar, Emma; Ferreira, Leticia D.; Filiz Ak, N.; Finley, Hayley; Fleming, Scott W.; Font-Ribera, Andreu; Frinchaboy, Peter M.; García-Hernández, D. A.; Pérez, A. E. García; Ge, Jian; Génova-Santos, R.; Gillespie, Bruce A.; Girardi, Léo; González Hernández, Jonay I.; Grebel, Eva K.; Gunn, James E.; Guo, Hong; Haggard, Daryl; Hamilton, Jean-Christophe; Harris, David W.; Hawley, Suzanne L.; Hearty, Frederick R.; Ho, Shirley; Hogg, David W.; Holtzman, Jon A.; Honscheid, Klaus; Huehnerhoff, J.; Ivans, Inese I.; Ivezić, Željko; Jacobson, Heather R.; Jiang, Linhua; Johansson, Jonas; Johnson, Jennifer A.; Kauffmann, Guinevere; Kirkby, David; Kirkpatrick, Jessica A.; Klaene, Mark A.; Knapp, Gillian R.; Kneib, Jean-Paul; Le Goff, Jean-Marc; Leauthaud, Alexie; Lee, Khee-Gan; Lee, Young Sun; Long, Daniel C.; Loomis, Craig P.; Lucatello, Sara; Lundgren, Britt; Lupton, Robert H.; Ma, Bo; Ma, Zhibo; MacDonald, Nicholas; Mack, Claude E.; Mahadevan, Suvrath; Maia, Marcio A. G.; Majewski, Steven R.; Makler, Martin; Malanushenko, Elena; Malanushenko, Viktor; Manchado, A.; Mandelbaum, Rachel; Manera, Marc; Maraston, Claudia; Margala, Daniel; Martell, Sarah L.; McBride, Cameron K.; McGreer, Ian D.; McMahon, Richard G.; Ménard, Brice; Meszaros, Sz.; Miralda-Escudé, Jordi; Montero-Dorta, Antonio D.; Montesano, Francesco; Morrison, Heather L.; Muna, Demitri; Munn, Jeffrey A.; Murayama, Hitoshi; Myers, Adam D.; Neto, A. F.; Nguyen, Duy Cuong; Nichol, Robert C.; Nidever, David L.; Noterdaeme, Pasquier; Nuza, Sebastián E.; Ogando, Ricardo L. C.; Olmstead, Matthew D.; Oravetz, Daniel J.; Owen, Russell; Padmanabhan, Nikhil; Palanque-Delabrouille, Nathalie; Pan, Kaike; Parejko, John K.; Parihar, Prachi; Pâris, Isabelle; Pattarakijwanich, Petchara; Pepper, Joshua; Percival, Will J.; Pérez-Fournon, Ismael; Pérez-Ràfols, Ignasi; Petitjean, Patrick; Pforr, Janine; Pieri, Matthew M.; Pinsonneault, Marc H.; Porto de Mello, G. F.; Prada, Francisco; Price-Whelan, Adrian M.; Raddick, M. Jordan; Rebolo, Rafael; Rich, James; Richards, Gordon T.; Robin, Annie C.; Rocha-Pinto, Helio J.; Rockosi, Constance M.; Roe, Natalie A.; Ross, Ashley J.; Ross, Nicholas P.; Rossi, Graziano; Rubiño-Martin, J. A.; Samushia, Lado; Sanchez Almeida, J.; Sánchez, Ariel G.; Santiago, Basílio; Sayres, Conor; Schlegel, David J.; Schlesinger, Katharine J.; Schmidt, Sarah J.; Schneider, Donald P.; Schultheis, Mathias; Schwope, Axel D.; Scóccola, C. G.; Seljak, Uros; Sheldon, Erin; Shen, Yue; Shu, Yiping; Simmerer, Jennifer; Simmons, Audrey E.; Skibba, Ramin A.; Skrutskie, M. F.; Slosar, A.; Sobreira, Flavia; Sobeck, Jennifer S.; Stassun, Keivan G.; Steele, Oliver; Steinmetz, Matthias; Strauss, Michael A.; Streblyanska, Alina; Suzuki, Nao; Swanson, Molly E. C.; Tal, Tomer; Thakar, Aniruddha R.; Thomas, Daniel; Thompson, Benjamin A.; Tinker, Jeremy L.; Tojeiro, Rita; Tremonti, Christy A.; Vargas Magaña, M.; Verde, Licia; Viel, Matteo; Vikas, Shailendra K.; Vogt, Nicole P.; Wake, David A.; Wang, Ji; Weaver, Benjamin A.; Weinberg, David H.; Weiner, Benjamin J.; West, Andrew A.; White, Martin; Wilson, John C.; Wisniewski, John P.; Wood-Vasey, W. M.; Yanny, Brian; Yèche, Christophe; York, Donald G.; Zamora, O.; Zasowski, Gail; Zehavi, Idit; Zhao, Gong-Bo; Zheng, Zheng; Zhu, Guangtun; Zinn, Joel C.

2012-11-19

The Sloan Digital Sky Survey III (SDSS-III) presents the first spectroscopic data from the Baryon Oscillation Spectroscopic Survey (BOSS). This ninth data release (DR9) of the SDSS project includes 535,995 new galaxy spectra (median z=0.52), 102,100 new quasar spectra (median z=2.32), and 90,897 new stellar spectra, along with the data presented in previous data releases. These spectra were obtained with the new BOSS spectrograph and were taken between 2009 December and 2011 July. In addition, the stellar parameters pipeline, which determines radial velocities, surface temperatures, surface gravities, and metallicities of stars, has been updated and refined with improvements in temperature estimates for stars with T_eff<5000 K and in metallicity estimates for stars with [Fe/H]>-0.5. DR9 includes new stellar parameters for all stars presented in DR8, including stars from SDSS-I and II, as well as those observed as part of the SDSS-III Sloan Extension for Galactic Understanding and Exploration-2 (SEGUE-2). The astrometry error introduced in the DR8 imaging catalogs has been corrected in the DR9 data products. The next data release for SDSS-III will be in Summer 2013, which will present the first data from the Apache Point Observatory Galactic Evolution Experiment (APOGEE) along with another year of data from BOSS, followed by the final SDSS-III data release in December 2014.

Spectroscopic output of {sup 125}I and {sup 103}Pd low dose rate brachytherapy sources

Energy Technology Data Exchange (ETDEWEB)

Usher-Moga, Jacqueline; Beach, Stephen M.; DeWerd, Larry A. [Department of Medical Physics, University of Wisconsin--Madison, Madison, Wisconsin 53705 (United States); Global Physics Solutions, St. Joseph, Michigan 49085 (United States); Department of Medical Physics, University of Wisconsin-Madison, Madison, Wisconsin 53705 (United States)

2009-01-15

The spectroscopic output of low dose rate (LDR) brachytherapy sources is dependent on the physical design and construction of the source. Characterization of the emitted photons from 12 {sup 125}I and 3 {sup 103}Pd LDR brachytherapy source models is presented. Photon spectra, both along the transverse bisector and at several polar angles, were measured in air with a high-purity reverse electrode germanium (REGe) detector. Measured spectra were corrected to in vacuo conditions via Monte Carlo and analytical methods. The tabulated and plotted spectroscopic data provide a more complete understanding of each source model's output characteristics than can be obtained with other measurement techniques. The variation in fluorescence yield of the {sup 125}I sources containing silver caused greater differences in the emitted spectra and average energies among these seed models than was observed for the {sup 103}Pd sources or the {sup 125}I sources that do not contain silver. Angular spectroscopic data further highlighted the effects of source construction unique to each model, as well as the asymmetric output of many seeds. These data demonstrate the need for the incorporation of such physically measured output characteristics in the Monte Carlo modeling process.

Studies on synthesis of diamond at high pressure and temperature

Science.gov (United States)

Kailath, Ansu J.

: (a) X-ray diffraction study of the phase composition of crystallization medium and inclusions in synthesized diamonds, (b) metallographic examination of the initial catalyst-solvent and the frozen slug after synthesis, (c) temperature dependence of the magnetic susceptibility of the initial catalyst-solvent and the frozen catalyst-solvent after synthesis, (d) scanning electron microscopic examination of the inclusion on the mechanically polished cross-sections of the synthesized crystals, (e) EDAX analysis of these observed inclusions and the frozen catalyst-solvent matrix after growth, (f) temperature dependence of the magnetic susceptibility of the synthesized crystals and (g) the Mossbauer spectroscopic analysis of the synthesized crystals. Different observations and the results obtained from these studies have been compiled and presented in chapter VI. Chapter VII illustrates the various conclusions drawn from the present studies.

Synthesis and characterization of magnetite nanoparticles from mineral magnetite

Energy Technology Data Exchange (ETDEWEB)

Morel, Mauricio, E-mail: mmorel@ing.uchile.cl [Laboratorio de Síntesis y Polímeros, Departamento de ciencias de los Materiales, Facultad de Ciencias Físicas y Matemáticas, Universidad de Chile, Santiago (Chile); Laboratorio de Materiales a Nanoescala, Departamento de ciencias de los Materiales, Facultad de Ciencias Físicas y Matemáticas, Universidad de Chile, Avenue Tupper 2069, Santiago (Chile); Martínez, Francisco, E-mail: polimart@ing.uchile.cl [Laboratorio de Síntesis y Polímeros, Departamento de ciencias de los Materiales, Facultad de Ciencias Físicas y Matemáticas, Universidad de Chile, Santiago (Chile); Mosquera, Edgar [Laboratorio de Materiales a Nanoescala, Departamento de ciencias de los Materiales, Facultad de Ciencias Físicas y Matemáticas, Universidad de Chile, Avenue Tupper 2069, Santiago (Chile)

2013-10-15

We have synthesized magnetite nanoparticles with sizes that range from 20 to 30 nm from mineral magnetite roughly 45 μm in size. The procedure consists in the dissolution of the mineral in an acidic medium and subsequent precipitation in a basic medium in the presence of oleic acid. Two experiments were conducted in different gaseous environments. The first was carried out in an environment exposed to air (M1) and the second in an N{sub 2} (M2) environment. The x-ray diffraction results showed a slight difference, which corresponds to the surface oxidation of magnetite. The sizes of the modified nanoparticles were determined through the Scherrer equation and transmission electron microscopy. An organic material mass loss corresponding to 18% was observed through a thermogravimetric analysis. The Fourier transform infrared spectroscopic analysis provides information about the type of bond that is formed on the surface of the nanoparticle, which corresponds to a bidentate chelate. The vibrating sample magnetometer results show a superparamagnetic behavior for sample M1. - Highlights: • A new method for synthesis of nanoparticles from mineral microparticles. • Search agreggate value to the mineral by mean nanoscience. • The stoichiometric ratio of the ions Fe{sup 2+} and Fe{sup 3+} from the mineral magnetite is synergistic.

Synthesis and characterization of magnetite nanoparticles from mineral magnetite

International Nuclear Information System (INIS)

Morel, Mauricio; Martínez, Francisco; Mosquera, Edgar

2013-01-01

We have synthesized magnetite nanoparticles with sizes that range from 20 to 30 nm from mineral magnetite roughly 45 μm in size. The procedure consists in the dissolution of the mineral in an acidic medium and subsequent precipitation in a basic medium in the presence of oleic acid. Two experiments were conducted in different gaseous environments. The first was carried out in an environment exposed to air (M1) and the second in an N 2 (M2) environment. The x-ray diffraction results showed a slight difference, which corresponds to the surface oxidation of magnetite. The sizes of the modified nanoparticles were determined through the Scherrer equation and transmission electron microscopy. An organic material mass loss corresponding to 18% was observed through a thermogravimetric analysis. The Fourier transform infrared spectroscopic analysis provides information about the type of bond that is formed on the surface of the nanoparticle, which corresponds to a bidentate chelate. The vibrating sample magnetometer results show a superparamagnetic behavior for sample M1. - Highlights: • A new method for synthesis of nanoparticles from mineral microparticles. • Search agreggate value to the mineral by mean nanoscience. • The stoichiometric ratio of the ions Fe 2+ and Fe 3+ from the mineral magnetite is synergistic

A closer look at the quadruply lensed quasar PSOJ0147: spectroscopic redshifts and microlensing effect

Science.gov (United States)

Lee, Chien-Hsiu

2018-04-01

I present a timely spectroscopic follow-up of the newly discovered, quadruply lensed quasar PSOJ0147 from the Pan-STARRS 1 survey. The newly acquired optical spectra with GMOS onboard the Gemini North Telescope allow us to pin down the redshifts of both the foreground lensing galaxy and the background lensed quasar to be z = 0.572 and 2.341, providing a firm basis for cosmography with future high-cadence photometric monitoring. I also inspect difference spectra from two of the quasar images, revealing the microlensing effect. Long-term spectroscopic follow-ups will shed lights on the structure of the active galactic nucleus and its environment.

Spectroscopic imaging of the pilocarpine model of human epilepsy suggests that early NAA reduction predicts epilepsy.

Science.gov (United States)

Gomes, W A; Lado, F A; de Lanerolle, N C; Takahashi, K; Pan, C; Hetherington, H P

2007-08-01

Reduced hippocampal N-acetyl aspartate (NAA) is commonly observed in patients with advanced, chronic temporal lobe epilepsy (TLE). It is unclear, however, whether an NAA deficit is also present during the clinically quiescent latent period that characterizes early TLE. This question has important implications for the use of MR spectroscopic imaging (MRSI) in the early identification of patients at risk for TLE. To determine whether NAA is diminished during the latent period, we obtained high-resolution (1)H spectroscopic imaging during the latent period of the rat pilocarpine model of human TLE. We used actively detuneable surface reception and volume transmission coils to enhance sensitivity and a semiautomated voxel shifting method to accurately position voxels within the hippocampi. During the latent period, 2 and 7 d following pilocarpine treatment, hippocampal NAA was significantly reduced by 27.5 +/- 6.9% (P NAA deficit is not due to neuron loss and therefore likely represents metabolic impairment of hippocampal neurons during the latent phase. Therefore, spectroscopic imaging provides an early marker for metabolic dysfunction in this model of TLE.

Spectroscopic and electric dipole properties of Sr+Ar and SrAr systems including high excited states

Science.gov (United States)

Hamdi, Rafika; Abdessalem, Kawther; Dardouri, Riadh; Al-Ghamdi, Attieh A.; Oujia, Brahim; Gadéa, Florent Xavier

2018-01-01

The spectroscopic properties of the fundamental and several excited states of Sr+Ar and SrAr, Van der Waals systems are investigated by employing an ab initio method in a pseudo-potential approach. The potential energy curves and the spectroscopic parameters are displayed for the 1-10 2Σ+, 1-6 2Π and 1-3 2Δ electronic states of the Sr+Ar molecule and for the 1-6 1Σ+, 1-4 3Σ+, 1-3 1,3Π and 1-3 1,3Δ states of the neutral molecule SrAr. In addition, from these curves, the vibrational levels and their energy spacing are deduced for Σ+, Π and Δ symmetries. The spectra of the permanent and transition dipole moments are studied for the 1,3Σ+ states of SrAr, which are considered to be two-electron systems and 2Σ+ states of the single electron Sr+Ar ion. The spectroscopic parameters obtained for each molecular system are compared with previous theoretical and experimental works. A significant correlation revealed the accuracy of our results.