Wyniki wyszukiwania - Biblioteka Nauki

1

Conformational studies of aliphatic secondary ozonides (propene, 1-butene and 1-heptene) by means of FTIR spectroscopy

100%

Bariseviciute R. , Ceponkus J. , Gruodis A. , Sablinskas V.

Open Chemistry

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2006

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tom 4

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nr 4

578-591

EN

Ozonization reaction of simple alkenes was studied by means of FT infrared absorption gas spectroscopy. The reaction was performed at 95 K in neat films of the reactants. IR absorption spectra of the gaseous products were recorded. The spectra were analyzed combining experimental results with theoretical calculations performed at B3LYP 6-311++G (3df, 3pd) level. We found that among all theoretically predicted conformers of propene secondary ozonide, only one which has the O-O half-chair configuration for the five membered ring and the radical attached in the equatorial position was present in the sample. Samples of 1-butene and 1-heptene secondary ozonides consist from two conformers of very similar energy (ΔH=0.3 kJ/mol). The most stable conformer for both ozonides is the one with O-O half-chair configuration of the five membered ring and the radical attached in equatorial position and the aliphatic chain in gauche position. The second stable conformer has the aliphatic chain in anti position.

2

Matrix isolation FTIR spectroscopical study of ethene secondary ozonide

100%

Bariseviciute R. , Ceponkus J. , Sablinskas V.

Open Chemistry

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2007

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tom 5

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nr 1

71-86

EN

A new method is used for the separation of ethene secondary ozonide (SOZ) from the other products of ethene ozonization reaction. The reaction was performed in the neat films of the reactants at 77 K. Ethene SOZ was separated from other products of the reaction by vacuum distillation at 190–210 K and analyzed by means of the matrix isolation IR absorption spectroscopy. Spectroscopic data from photolysis of the matrix isolated ozonide was used as an argument for assignment of the infrared spectral bands either to ethene SOZ or to other products of the reaction. The spectra of ethene SOZ isolated in the Ar matrix were analyzed by combining experimental results with the theoretical calculations performed at the MP2 6-311+G (3df, 3pd) level. A new assignment of some experimental fundamental bands is proposed taking in to account the Fermi resonance between CH stretch and the five membered ring vibrations. For the first time more than 30 weak infrared absorption bands were observed and assigned to various combination vibrations and overtones. By using new spectral information concerning the overtones and the combination bands it is concluded that the dissociation of unstable ethene SOZ involving breaking of any of the four CO bonds of the five membered ring of ethene SOZ has low probability. Dissociation of the ring starts from breaking of the OO bond. [...]

3

Analysis of braking marks left by vehicles equipped with ABS with IR spectroscopy – different types of asphalt

100%

Sys E. , Kubiak P. , Gosławski Ł. , Zakrzewicz W.

Archiwum Motoryzacji

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2021

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tom Vol. 93, nr 3

5--14

EN

Detailed analysis of literature showed that there is no method that can be used in order to investigate skid marks left by vehicles equipped with ABS. Authors decided to identify braking trace by using IR spectroscopy. Preliminary studies have been performed and results were promising. Due to that fact authors decided to conduct detailed research where the influence of various factors on the possibility of revealing breaking traces would be taken into account. This article is the first in a series of articles taking into account the influence of various factors on the possibility of revealing breaking marks using IR spectroscopy. In this article the influence of the type of asphalt was studied. Authors conducted tests with the most popular types of asphalts used for the wearing course. 100 samples from 5 different types of asphalt were prepared. Each sample was measured 3 times to create its spectrum. The results were analyzed thoroughly using the dedicated SpectraGryph software. The analysis showed that for 4 out of 5 types of tested asphalt, the braking traces were visible at a wavelength of approximately 11 500 nm. Only for the rubberized asphalt there weren’t possibility to reveal skid mark.

4

Pre and Post Effect of Swift Heavy Ion Irradiation on Infrared Spectral Evolution of Y3+xFe5-xO12 (x = 0.0 – 1.0) System

100%

Modi K. B. , Shah S. J. , Kathad C. R. , Sharma P. U.

International Letters of Chemistry, Physics and Astronomy

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2015

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tom Vol. 44

66--72

EN

Present work aims to investigate the effect of Y3+ - substitution and 50 MeV, Li3+ ion irradiation (fluence: 5 x 1013 ions/cm2) on infrared spectral evolution of Y3+xFe5-xO12 (x = 0.0, 0.2 0.4, 0.6, 0.8 and 1.0) garnet system. Infrared absorption spectra for x = 0.0 – 0.6 compositions show three absorption bands while x = 0.8 – 1.0 compositions are characterized by two absorption bands, identical with IR spectra of rare earth ortho ferrites. The position and intensity of bands are found to be influenced by Y3+ - substitution. The intensity of absorption bands for x = 0.0 – 0.4 compositions is found to increase, while for x = 0.6 – 1.0 compositions no effect of swift heavy ion irradiation has been observed. The results have been explain in the light of SHII induced defect states, partial removal of un-wanted YFeO3 phase and change in structural parameters. It seems that YFeO3 phase is irradiation hard phase.

5

Non-invasive blood glucose measurement

100%

Kossowski T. , Kossowska K. , Stasiński R.

Measurement Automation Monitoring

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2016

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tom Vol. 62, No. 5

175--177

EN

The paper presents a system for measuring blood glucose level based on spectroscopy in the near infrared range. Specific features of this system are limited spectral range of measurements, and the use of visible light detector to identify the density of irradiated tissue and to correct measurement results in the infrared range. Presented are principles of measuring system construction, including measures undertaken to increase its precision and results of tests carried out using the constructed measurement system. The results are close to those obtained from a traditional meter.

6

Analysis of braking marks left by vehicles equipped with ABS with IR spectroscopy

100%

Gosławski L. , Kubiak P. , Mrowicki A. , Soghabatyan T. , Sys E. , Wang Y.-W. , Zou T.

Archiwum Motoryzacji

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2019

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tom Vol. 84, nr 2

33--43

EN

This paper presents the possible use for IR spectroscopy to reveal skid marks left by cars equipped with Anti-lock Braking System. Detailed analysis of literature showed that there is no method that can be used in order to investigate this kind of tire marks. Up till now only two techniques have been devised. The first one is Method of Image Refinement which consists of transforming the image from the scene of the accident using dedicated graphics software. Second method includes analysis of traces using a thermal imaging camera. This study presents an innovative approach to the problem. Numerous analyses using IR spectroscopy were conducted to check the suitability of this method. The research performed on a Thermo Scientific FTIR Nicolet iS50 Spectrophotometer with an ATR attachment. 40 samples from 10 different types of asphalt were prepared. Each sample was measured 3 times to create its spectrum. The results were analyzed thoroughly using the dedicated SpectraGryph software. Analysis show that the wavelength which makes the braking marks visible is found within the mid-infrared range. Finally, it was found wavelength in which skid marks should be visible. This range is located in the mid-infrared.

7

Coordination properties of N,O-carboxymethyl chitosan (NOCC). Synthesis and equilibrium studies of some metal ion complexes. Ternary complexes involving Cu(II) with (NOCC) and some biorelevant ligand

100%

Shoukry A. , Hosny W.

Open Chemistry

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2012

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tom 10

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nr 1

59-70

EN

In the present study, the acid-base equilibria of N,O-carboxymethy chitosan abbreviated as (NOCC), is investigated. The complex formation equilibria with the metal ions Cu(II), Ni(II), Co(II), Mn(II), and Zn(II) are investigated potentiometrically. The stability constant values of the binary and ternary complexes formed in solution were determined and the binding centers of the ligands were assigned. The relationships between the properties of the studied central metal ions as ionic radius, electronegativity, atomic number, and ionization potential, and the stability constants of the formed complexes were investigated in an effort to give information about the nature of chemical bonding in complexes and make possible the calculation of unknown stability constants. Cu(II), Ni(II), and U(VI) complexes with NOCC are isolated as solid complexes and characterized by conventional chemical and physical methods. The structures of the isolated solid complexes are proposed on the basis of the spectral and magnetic studies. The ternary copper(II) complexes involving NOCC and various biologically relevant ligands containing different functional groups, as amino acids and DNA constituents are investigated. The stability constants of the complexes are determined and the concentration distribution diagrams of the complexes are evaluated.

8

Infrared spectroscopic study of magnesium oxide catalysts doped with sodium ions

100%

Ignaczak W. , Jóżwiak W. , Szubiakiewicz E. , Paryjczak T.

Polish Journal of Chemistry

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1999

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tom vol. 73 nr 4

645-654

EN

Infrared results concerning the surface species in MgO catalysts doped with Na+ ions are presented. Different surface carbonate structures and hydroxyls groups have been found. It was assumed that created carbonate compounds could be involved in decreasing of MgO specific surface area. Sodium carbonate and unidentate carbonate structures may cause elimination and blockage of low coordination sites of MgO surface, being responsible both for hydrogen detachment from CH4 molecules and for oxidation of methyl radicals to carbon oxides - the undesired reactions of oxidative coupling of methane (OCM). It was observed that increasing temperature led to decomposition of surface bicarbonate and unidentate carbonate structures. Some of them are being reconverted to more stable bicarbonate structures. Carbon dioxide and water desorptions result in gradual restoration of low coordinated sites of MgO, corresponding to high selectivity to C2 hydrocarbon formation. Sodium ions may also cause structural changes in MgO lattice. The catalysts were active and selective above 950 K for C2 hydrocarbon formation, although sodium carbonate is sufficiently stable under the conditions of the OCM process.

9

Synthesis and Characterization of Novel Carbacylamidophosphate Derivatives: Crystal Structures of (CF3)C(O)NHP(O)(NC6H12)2, (p-Br-C6H4)C(O)NHP(O)(NC6H12)2 and (p-Cl-C6H4)C(O)NHP(O)(NC6H12)2

100%

Gholivand K. , Mojahed F. , Alizadehgan A. M.

Polish Journal of Chemistry

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2007

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tom Vol. 81, nr 10

1829-1829

EN

Several new arbacylamidophosphates with formula (X)C(O)NHP(O)(NC6H12)2, X =CH2Cl, 1b; CHCl2, 2b; CCl3, 3b; CF3, 4b; MeC6H4, 5b; BrC6H4, 7b; ClC6H4, 8b were synthesized and characterized by 1H, 31P and13C NMR and IR spectroscopy and elemental analysis. The effect of PNCC dihedral angles on the 3J(P,C aliphatic) was studied. The structures of the 4b, 7b and 8b were determined by single-crystal X-ray diffraction techniques. The structural data of these compounds are compared with similar carbacylamidophosphates.

10

Thermal properties of multinuclear Ti(IV) and Zr(IV) carboxylate derivatives using thermal analysis and variable temperature MS and IR methods

88%

Piszczek P. , Grodzicki A. , Richert M. , Radtke A.

Materials Science Poland

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2005

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tom Vol. 23, No. 3

663--670

EN

Studies of thermal properties of multinuclear Ti(IV) and Zr(IV) carboxylates of general formulas [Ti8O8(O2CBu)16] (1) and [Zr6O8(O2CBu)12] (2), which can be used as a potential source compounds, to produce TiO2 and ZrO2 thin layers, were carried out. Thermogravimetric methods (TG/DTG/DTA), mass spectrometry (MS-EI), and variable temperature infrared spectroscopy (VT-IR) have been used in order to determine the thermal decomposition pathway, identification of the volatile titanium and zirconium species in vapors, and determination their thermal stability. Moreover applications of Ti(IV) and Zr(IV) compounds in MOCVD experiments, as a potential metal oxide precursors, have been discussed.

11

Biogenic iron compounds: XRD, Mossbauer and FTIR study

88%

Shopska M. , Cherkezova-Zheleva Z. , Paneva D. , Iliev M. , Kadinov G. , Mitov I. , Groudeva V.

Open Chemistry

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2013

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tom 11

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nr 2

215-227

EN

Materials based on biogenic iron oxides, which are a product of the metabolic activities of the neutrophilic iron-oxidizing bacteria (NIOB) from Sphaerotilus-Leptothrix group, were investigated. Natural microbial probes were collected from freshwater flow from Vitosha Mountain (Bulgaria) and cultivated under laboratory conditions in respect to select suitable cultures and conditions (nutrition media) for biomaterial accumulation of biogenic oxides. Samples were studied by physicochemical methods: X-ray diffraction, Mossbauer spectroscopy and IR spectroscopy. Their phase composition and physicochemical properties were obtained. Presence of both amorphous and crystal phase (ultra- and highly dispersed particles) was proved. Iron-containing compound in the natural biomass consists of α-FeOOH. The cultivated materials have more complex composition with iron-containing ingredients as α-FeOOH, Γ-FeOOH, Γ-Fe2O3 and Fe3O4. The sample of natural biomass was tested in reaction of CO oxidation and it showed potential to be used as catalyst support. [...]

12

Synthesis and Characterization of Novel Phosphorictriamide Derivatives with Morpholine Substituents: Crystal Structures of Substituents: Crystal Structures of (CF3)C(O)NHP(O)(NC4H8O)2 and (p-Br-C6H4)C(O)NHP(O)(NC4H8O)2

88%

Gholivand K. , Mojahed F. , Alizadehgan A.

Polish Journal of Chemistry

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2007

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tom Vol. 81, nr 3

393-402

EN

Using phosphorus pentachloride as a substrate, carbacylamidophosphates of the general formula (R)C(O)NHP(O)(NC4H8O)2, where R = CH2Cl I; CHCl2 II; CCl3 III; CF3 IV; p-Me-C6H4V; p-Br-C6H4 VI; p-Cl-C6H4 VII, were prepared and characterized by 1H, 31P and 13C NMR, IR spectroscopy and elemental analysis. Different carboxylic amides attached to phosphorus nuclei affect on IR and NMR spectra. Three-bond coupling constants between phosphorus and carbon nucleus, 3J(P,Caliphatic) in the synthesized compounds, were greater than two-bond coupling constants, 2J(P,Caliphatic). The structures of IV and VI were determined by single-crystal X-ray diffraction techniques. The compounds IV and VI formed centrosymmetric dimers via intermolecular N-HźźźO=P hydrogen bonds.

13

Spectroscopic properties of dithallium phthalocyanine

88%

Janczak T.

Polish Journal of Chemistry

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1999

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tom vol. 73 nr 3

437-446

EN

Black-green dithallium (I) phthalocyanine complex with metallic conductivity has been obtained in crystalline form. The UV-VIS, IR, far IR and resonance Raman spectra of the Tl2Pc complex are presented. The absorption electronic spectra indicate the proximity of the HOMO and LUMO of the Pc ligand in energy. The additional band at 516 nm is attributed to CT transition. The vibrational spectroscopic data of dithallium(I) phthalocyanine complex are discussed in terms of specific chemical bonds and atomic group and compared with the other phthalocyanines. An empirical vibrational assignment of the observed fundamentals is given.

14

Physico-chemical properties investigation of softwood surface after treatment with organic anhydride

88%

Bodîrlău R. , Teacă C.-A. , Roşu D. , Roşu L. , Varganici C.-D. , Coroabǎ A.

Open Chemistry

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2013

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tom 11

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nr 12

2098-2106

EN

Wood originating from a softwood species was subjected to chemical treatment by reaction with succinic anhydride in N, N-dimethylformamide at different concentration values. Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy analysis were used to study changes that occurred on a softwood surface. The extent of chemical treatment on softwood was evaluated by determining the weight percent gain values. Thermal properties of modified softwood and the water absorption were also evaluated. The chemical treatment with succinic anhydride influenced the thermal stability of the softwood samples with increasing anhydride concentration levels. [...]

15

Shape memory polyurethanes based on recycled polyvinyl butyral. I. Synthesis and morphology

88%

Tsonev T. , Herzog M. , Nenkova S.

Open Chemistry

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2013

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tom 11

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nr 12

2058-2065

EN

Shape memory polyurethanes (SMPUs) were synthesized by 4,4′-diphenylmethane diisocyanate (MDI), hexane-1,6-diol (HD), polypropylene glycol (PPG), and recycled polyvinyl butyral (PVB). Dynamic mechanical analysis, differential scanning calorimetry and Fourier transformation infrared attenuated total reflection spectroscopy was used to characterize the poly (vinylbutyral-urethanes). Micro-phase domain separation of hard and soft segments and phase inversion were investigated. Increasing the hard segment content, i.e., average hard segment molecular weight, leads to an increase in the degree of micro-phase separation, hard domain order and crystallinity. The crystalline hard segment structures combined with the elastic nature of soft segment matrix provide enough physical and chemical crosslinks to have shape memory effect.

16

Microspectroscopic infrared specular reflection chemical imaging of multi-component urinary stones: MIR vs. FIR

88%

Pucetaite M. , Tamosaityte S. , Engdahl A. , Ceponkus J. , Sablinskas V. , Uvdal P.

Open Chemistry

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2014

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tom 12

|

nr 1

44-52

EN

Specular reflection infrared microspectroscopy was used for chemical imaging of cross-sectioned urinary stones to determine their chemical composition and morphology simultaneously. Absorption spectral bands were recovered from reflection spectra by Kramers-Kronig transform. FUse of far-infrared radiation provides high-contrast images and allows more precise constituent distribution determinations than mid-infrared because band asymmetry after the transform caused by diffuse reflection is less in the far-infrared. [...]

17

Badania FT-IR zeolitów z różnych grup strukturalnych

75%

Mozgawa W. , Król M. , Barczyk K.

Chemik

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2011

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tom Vol. 65, nr 7

667-674

PL

W pracy przedstawiono wyniki badań FT-IR zeolitów (głównie naturalnych) należących do siedmiu głównych grup strukturalnych. Interpretację widm oscylacyjnych oparto na identyfikacji pasm związanych z drganiami charakterystycznymi SBU. Rozpoznania pasm dokonano na podstawie wyników poprzednich prac, w których w oparciu o obliczenia ab initio analizowano wizualizacje drgań otrzymane dla jednostek strukturalnych zbudowanych z pojedynczych i podwójnych pierścieni 4- i 6-członowych [4,5]. Identyfikacja tych pasm dostarcza informacji związanych z budową glinokrzemianowego szkieletu zeolitów, jak i o wpływie na widma kationów wymiennych.

EN

The paper presents the results of FT-IR studies of zeolites (mainly natural) belonging to the seven major structural groups. Interpretation of vibrational spectra has been based on the identification of the bands associated with typical SBU vibrations. On the grounds of the previous works [4, 5], in which, based on ab initio calculations, visualization of vibration obtained for the structural units composed of single and double 4- and 6-membered rings had been analyzed, the bands have been assigned. Identification of these bands provides information related to the construction of the aluminosilicate framework of zeolites as well as about influence of exchangeable cations on the spectra.

18

Spektroskopia fotoakustyczna w podczerwieni

75%

Ryczkowski J.

LAB Laboratoria, Aparatura, Badania

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2007

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tom R. 12, nr 6

6-10

19

Kinetics of Polymorphic Transitions in Energetic Compounds

75%

Chukanov N. V. , Zakharov V. V. , Korsunskiy B. L. , Chervonnyi A. D. , Vozchikova S. A.

Central European Journal of Energetic Materials

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2016

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tom Vol. 13, no. 2

483--504

EN

Available data on the kinetics of polymorphic transitions (PTs) in energetic compounds under isothermal conditions are summarized and discussed. It is shown that the general kinetic regularities of these processes (stepwise and continuous regimes) depend on their topotactic mode (frontal or quasi-homogeneous, respectively). In reverse PTs, a nucleation stage is not observed, which is explained by the presence of nuclei of the low-temperature polymorph in the preheated sample. The influence of mechanical effects on the kinetics of PTs in molecular crystals is discussed.

20

Spektroskopia ramanowska jako technika uzupełniająca się ze spektroskopią IR

75%

LAB Laboratoria, Aparatura, Badania

|

2011

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tom R. 16, nr 2

30-32