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EN
There were investigated some initial structural transformations which take place in urea-furfuryl binding systems. They were investigated by FTIR spectrometry. There were also used two different techniques: transmission and diffuse reflection (DRS). The spectra were recorded within a range of 400-4000cm-1. the subjects of studies were two modified urea-furan resins (Kaltharz F700 and Kaltharz U404U) and the hardening process with two activators. Changes in FTIR spectra during hardening of the resins were recorded after the time of 1,2,4,8 and 24 hours. In comparison there were also examined mechanical properties of sands prepared with these resins. Changes in the spectra of both resins with different activators were visible in the same range of 1400-1700 cm-1 in about 2 hours since the moment of making the sand; then the number of the bands and their intesity were decreasing. From the conducted tensile and bending tests of the sand it follows that the highest increase of these parameters takes place within the time of up to 2 hours; then the strength increases but only slightly. As it follows from the preliminary studies, FTIR spectroscopy, and DRS technique - in particular, can be helpful in assessment of the hardening degree of moulding sands with organic binders and in getting familiar with the mechanism of the hardening process of these binders. there are also needed further investigations, especially to identify all the peaks in obtained spectrums.
PL
Przeprowadzono wstępne badania przemian strukturalnych zachodzących podczas procesu wiązania żywic mocznikowo-furanowych. badania prowadzono stosując fourierowską spektrometrię w podczerwieni. zastosowano dwie techniki pomiarowe: transmisyjną oraz technikę rozproszonego odbicia (DRS). Widma były rejestrowane w zakresie 400-4000cm-1. Przedmiotem badań były dwie modyfikowane żywice mocznikowo-furanowe (Kaltharz f700 i Kaltharz u404U). Widma FTIR podczas procesu utwardzania żywic były rejestrowane po czasie 1,2,4, 8 i 24 godzin. Równocześnie w tym samym czasie prowadzono badania właściwości wytrzymałościowych mas z tymi żywicami przy dodatku dwóch różnych aktywatorów. zmiany w widmach dla mas z obudwoma żywicami i różnymi aktywatorami były widoczne po ok. 2 godzinach od sporządzenia w tym samym zakresie 1400-1700cm-1; poźniej intensywność pasm i ich liczba maleje. z przeprowadzonych testów wytrzymałościowych mas na rozciaganie i zginanie wynika, że największy wzrost tych parametrów ma miejsce również w okresie do 2 godzin, a nastepnie wytrzymalość wzrasta już nieznacznie. Jak wynika z powyższych wstepnych badań metoda spektroskopii FTIR, a szczególnie technika DRS mogą być pomocne przy ocenie stopnia utwardzenia tych spoiw.
EN
Results of IR study of the systems NH4ReO4/Al2O3 and NH4ReO4/Al2O3-SiO2 heated in the range 293-723 K are given. The systems contained rhenium in amounts corresponding to those in typical heterogeneous catalysts of olefin metathesis. The IR absorption spectra, recorded for the wavelengths 1700-1300 cm-1, enabled detection of adsorption at the Brönsted and Lewis type acid centres of water and ammonia, released during thermal decomposition of ammonium perrhenate. The spectra indicated a similarity between the adsorption centres present on the surface of the systems 17.8 wt.% NH4ReO4/Al2O3 and 3.3 wt.% NH4ReO4/Al2O3-SiO2 and those on the surface of the systems 3.3 and 9.9 wt.% NH4ReO4/Al2O3. The presence of adsorption centres in the former systems should be related to the phase of the surface rhenium species, while in the latter the centres occur on the surface of the support.
PL
Stosując technikę filmów węglowych metodą FTIR, badano reakcję katalitycznego rozkładu NO za pomocą CH4 na węglach czystych oraz promowanych Pt, w zakresie temperatur 200-350°C. Widma zmian spektralnych filmu węglowego promowanego Pt wykazały, iż NO w podwyższonych temperaturach ulega chemisorpcji, w wyniku której powstają powierzchniowe układy nitrowe. W wyniku reakcji jako produkty pośrednie tworzą się również układy cyjankowe i izocyjanianowe.
EN
Carbon film technique bas been used to investigate the catalytic reduction or NO by CH4 with the use of FTIR spectroscopy, on carbon and carbon supported Pt catalyst, in the range of temperature from 200 to 350°C. The spectral changes of the carbon supported Pt catalyst showed that in higher temperatures NO is chemisorbed in a form of surface nitrocompounds. As a result of the NO/C4 reaction the -CN and -NCO structures as intermediates are formed.
PL
Metodą spektroskopii w podczerwieni badano charakter oddziaływań NO z węglami oraz katalizatorami naniesionymi na powierzchnię węglową. Dodatek 1% Pt do nieutlenionego węgla znacznie zwiększa zdolności katalitycznego rozkładu NO. Konwersja NO wzrasta wraz ze wzrostem temperatury. Widma FTIR tlenków azotu rejestrowano w kuwecie gazowej o przedłużonej drodze optycznej.
EN
The interactions or NO with carbon and carbon supported catalysts have been investigated by means of infrared spectroscopy. The addition of only 1% of Pt to the unoxidized carbon improved considerably the NO decomposition. The NO conversion increased with increasing reaction temperature in the whole temperature range. The effluent from the microreactor was analyzed by FTIR spectroscopy. The FTIR spectra of nitrogen oxides were recorded in multiple reflection gas cell.
EN
The paper presents results of research on selected physico-chemical parameters of engine oils from farm tractors based on the date of their change assumed by the user. 17 samples of used engine oil from farm tractors of various producers and with a varied exploitation course were analysed. Oils for research were collected during oil change, registering the service life of oil each time. They were obtained from service points that repair farm tractors in the region of Lublin Province. The studies were to verify whether a decision concerning oil change taken by tractor users after specific time of operation of an engine was good. Number of exceedings of the threshold values of parameters of engine oil which are responsible for correct lubrication were the basis for evaluation.
PL
W pracy przedstawiono wyniki badań wybranych parametrów fizykochemicznych olejów silnikowych pochodzących z ciągników rolniczych, bazując na terminie wymiany oleju przyjętym przez użytkownika ciągnika. Analizie poddano 17 próbek przepracowanego oleju silnikowego, pochodzących z ciągników rolniczych różnych producentów i o różnym przebiegu eksploatacyjnym. Oleje do badań pobrano podczas wymiany oleju, każdorazowo rejestrując resurs oleju. Pozyskano je z serwisów zajmujących się naprawami ciągników rolniczych z terenu woj. lubelskiego. Przeprowadzone badania miały na celu sprawdzenie, czy podjęta przez użytkowników ciągników decyzja o wymianie oleju po określonym czasie pracy silnika, była właściwa. Ocenę przeprowadzono w oparciu o analizę liczby przekroczeń wartości granicznych parametrów, odpowiadających za zdolność oleju silnikowego do prawidłowego smarowania.
6
75%
PL
Wykorzystano metodę spektroskopii fourierowskiej (FT-IR) do oceny zmian struktury fazowej multiblokowych elastomerów uretanowych, zachodzących pod wpływem temperatury wygrzewania 60–120°C. Na podstawie gęstości wiązań wodorowych pomiędzy ugrupowaniami uretanowymi wyznaczono stopień separacji fazowej i stopień wymieszania faz. W celu oszacowania zmian masy cząsteczkowej wyznaczono lepkość istotną. Oznaczono także gęstość analizowanych materiałów. Stwierdzono, że wraz ze wzrostem temperatury wygrzewania znacznie rośnie średnia masa cząsteczkowa poliuretanów oraz stopień separacji faz. Nie odnotowano wpływu temperatury wygrzewania na gęstość poliuretanów.
EN
Poly(tetramethyleneoxide) contg. soft segments (60% by mass, mol. mass 1000) was converted in reaction with 4,4’-methylenebis(phenyl isocyanate) (6% excess) and 1,4-butanediol at 120°C for 30 min under pressure of 10 Pa to a prepolymer annealed then to a multiblock elastomer at 60–120°C. Phase sepn. of resulting polyurethanes was studied by Fourier-transform IR spectroscopy, while the mol. mass was detd. by intrinsic viscosity measurements. The increase in annealing temp. resulted in raise in phase sepn. and mol. mass, whilst no effect on the polymer d. was obsd.
7
Content available remote Interaction in the mixed adsorption monolayer at the liquid/liquid interface
75%
EN
The FT-IR spectrum for two chelating metal ion extractants: 2-hydroxy-5-nonylacetophenone oxime (HNAF) and 1-phenyldecane-1,3-dion (b-diketone) and decanol used as a modifier were presented. Moreover, two equimolar binary mixtures of extractant/extractant and extractant/modifier type were considered. The interaction between two extractants or the extractant and modifier molecules adsorbed at the mixed adsorption monolayer formed in extraction systems were discussed. The usefulness of the spectral technique (FT-IR) for studying the formation of a new ligand association adducts between the extractants and modifiers or two extractants in a binary mixture as well as a formation of self-association adducts of the extractants molecules were presented.
PL
W niniejszej pracy przedmiotem badań były wulkanizaty kauczuku butadienowo-styrenowego (SBR) z parafinami oraz oligomerami etylenu. Szybkość migracji zbadano metodą spektroskopii w podczerwieni, wykorzystując zjawisko całkowitego wewnętrznego odbicia (FTIR-IRS). Morfologię powierzchni wykwitów zbadano za pomoca mokroskopu sił atomowych (AFM). Badania tribologiczne wykonano w skali zarówno mikro jak i w makroskopowej. Stwierdzono występowanie korelacji pomiędzy dlugością łańcucha alifatycznego parafiny a szybkością migracji i morfologią wykwitu. Właściwości tribologiczne omówione zostały w kontekście budowy i struktury wykwitów.
EN
Rubber is multiphase and multicomponent system, containing among others some low molecular weight substances. They can migrate towards surface of a sample creating a bloom, what ensures protection of rubber goods against ozone. For this purpose n-parafin or microcrystalline waxes are introduced to rubber mixes. Although studying of low molecular weight substances surface migration has a long history its mechanism still reminds unexplained. Tribological consequences of blooming are seldom the subject of studies. In the present work migration of serval n-paraffins and oligomeric ethylenes in styrenebutadiene rubber (SBR) matrix was investigated. Kinetics of migration were determined by infrared spectroscopy, applying method of internal reflection (FTIR-IRS). Atomic force microscopy (AFM) was used for studying morphology of blooms. Tribological properties were investigated both in micro- and macroscale. Correlation between aliphatic chain length, blooming rate and bloom morphology was found. Tribological properties were discussed in relation to composition and structure of a bloom.
PL
Jednym z problemów podczas eksploatacji złóż węglowodorów jest wysoka produkcja wody złożowej z odwiertów ropnych lub gazowych. Ma to wpływ na ekonomikę procesu ich wydobycia, a tym samym na czas funkcjonowania odwiertów produkcyjnych o dużym zawodnieniu. By ograniczyć produkcję wody z tych odwiertów, stosuje się zabiegi mające na celu ograniczenie przepuszczalności za pomocą zatłaczanych środków chemicznych lub izolację w sposób mechaniczny ścieżek dopływu wody. Żele krzemianowe stanowią przyjazny dla środowiska zamiennik powszechnie stosowanych żeli polimerowych. W artykule przedstawiono laboratoryjną ocenę modyfikacji przepuszczalności skal zbiornikowych. W celu zrozumienia mechanizmu utraty przepuszczalności zostały wykonane badania interakcji cieczy zabiegowej z minerałami zawartymi w skale. Zmiany w strukturze zarówno żelu, jak i skały były analizowane z pomocą spektroskopii w podczerwieni FTIR.
EN
Water is commonly co-produced with the hydrocarbons saturating reservoir rock. Excessive water production is prevalent in mature fields and can have an impact on the profitability of oil and gas assets. Therefore, in order to mitigate water related issues, there is a need to use mechanical or chemical conformance technologies. One of the environmentally friendly alternatives for commonly used polymers are silicate systems. This paper presents evaluation of silicate gels as a water shut-off agent. In order to understand the permeability reduction phenomenon, interactions between treatment fluid and minerals were determined. The changes in gel structure were analyzed using FTIR technique.
PL
W artykule przedstawiono pomiary promieniowania procesu spalania biomasy. Do pomiarów wykorzystano spektrometr FTIR o otwartej ścieżce pomiarowej. Omówiono różnicę pomiędzy klasycznymi pomiarami spektroskopowymi, a pomiarami zdalnymi (pasywnymi, emisyjnymi). Dokonano analizy i porównania widma promieniowania z boku płomienia oraz od strony wylotu spalin.
EN
This paper describes measurements of the emission spectra of combustion of biomass fuel. Passive open path FTIR system has been used. By analysing the spectral measurements the state of the combustion process was unveiled. The radiation data was measured at different positions in the chamber.
11
Content available remote Methotrexate binding causes structural and functional changes in lung cystatin
71%
EN
Regulation of cysteine proteinases and their inhibitors is of utmost importance in diseases like lung cancer, chronic inflammatory conditions such as asthma, emphysema, and idiopathic pulmonary fibrosis. Protease-antiprotease imbalance accelerates disease progression. In the present study, the effect of antineoplastic and antirheumatic drug methotrexate (MTX) on lung cystatin (a cysteine protease inhibitor) was studied to explore drug induced changes in functional and structural integrity of the protein. The basic binding interaction was studied by UV-absorption, FT-IR and fluorescence spectroscopy. The quenching of protein fluorescence confirmed the binding of MTX with goat lung cystatin (GLC-I). Stern-Volmer analysis of MTX-GLC-I system at different temperatures indicates the presence of static component in the quenching mechanism. The thermodynamic parameters ΔH0 and ΔS0 were -3.8 kJ/mol and 94.97 J•mol-1•K-1, respectively, indicating that both hydrogen bonds and hydrophobic interactions played a major role in the binding of MTX to GLC-I. Methotrexate (7 µM) caused complete inactivation of lung cystatin after 6 hours. The results of FT-IR spectroscopy reflect perturbation of the goat lung cystatin on interaction with MTX. Methotrexate induced loss of function change in the inhibitor could provide a rationale for the off target tissue injury caused by the drug and for the design of agents against such an injury.
EN
This paper addresses problems arising from in situ measurement of gas content and temperature. Such measurements can be considered indirect. Transmittance or natural radiation of a gas is measured directly. The latter method (spectral radiation measurement) is often called spectral remote sensing. Its primary uses are in astronomy and in the measurement of atmospheric composition. In industrial processes, in situ spectroscopic measurements in the plant are often made with an open path Fourier Transform Infrared (FTIR) spectrometer. The main difficulty in this approach is related to the calibration process, which often cannot be carried out in the manner used in the laboratory. Spectral information can be obtained from open path spectroscopic measurements using mathematical modeling, and by solving the inverse problem. Determination of gas content based on spectral measurements requires comparison of the measured and modeled spectra. This paper proposes a method for the simultaneous use of multiple lines to determine the gas content. The integrated absorptions of many spectral lines permits calculation of the average band absorption. An inverse model based on neural networks is used to determine gas content based on mid-infrared spectra at variable temperatures.
EN
The 1:1 and 2:1 complexes of trigonelline (TRG) with HBr, HI, HNO3, HClO4 and HBF4 have been synthesized and their FTIR, 1H and 13C NMR spectra were analyzed. The 1:1 complexes are divided into two groups. The first group includes complexes with HBr,HI andHNO3, in which a proton is transferred from the acid to TRG and the anions are bonded with the carboxylic group, COOHźźźX- (1). The second comprises complexes with HClO4 and HBF4, with two molecules of protonated TRG forming dimer, like benzoic acid, and the anions interacting exclusively with the positively charged nitrogen atoms (2). All 2:1 complexes crystallized with one water molecule and their FTIR spectra are of Had4i type iii, characterized by an intense broad (continuum) absorption below 1600 cm-1 typical of a short-strong hydrogen bond (SSHB) with a delocalized proton and a single _C=O band. In these complexes the water molecule interacts electrostatically with one positively charged nitrogen atom and the anions with the second one (3). The water molecule additionally forms a hydrogen bond with Br, I and NO3 ions. The proton and carbon chemical shifts of the complexes in D2O have been determined and discussed.
14
Content available remote Synthesis and characterisation of SnO2 films obtained by a wet chemical process
71%
EN
SnO2 thin films, being n-type semiconductors, have wide application in the field of sensor technology. They are obtained by a wet chemical process, using SnCl2o2H2O as a tin containing precursor. The films thus obtained were subjected to optical, X-ray diffraction (XRD), microstructural, FTIR and Raman studies.
EN
Spectral remote sensing is a very popular method in atmospheric monitoring. The paper presents an approach that involves mid-infrared spectral measurements of combustion processes. The dominant feature in this spectral range is CO2 radiation, which is used to determine the maximum temperature of nonluminous flames. Efforts are also made to determine the temperature profile of hot CO2, but they are limited to the laboratory conditions. The paper presents an analysis of the radiation spectrum of a non-uniform-temperature gas environment using a radiative transfer equation. Particularly important are the presented experimental measurements of various stages of the combustion process. They allow for a qualitative description of the physical phenomena involved in the process and therefore permit diagnostics. The next step is determination of a non-uniform-temperature profile based on the spectral radiation intensity with the 8 m optical path length.
EN
Open-Path Fourier Transform Infrared OP-FTIR spectrometers are commonly used for the measurement of atmospheric pollutants and of gases in industrial processes. Spectral interpretation for the determination of gas concentrations is based on the HITRAN database line-by-line modeling method. This article describes algorithms used to model gas spectra and to determine gas concentration under variable temperatures. Integration of individual rotational lines has been used to reduce the impact of spectrometer functions on the comparison of both measured and synthetic modeled spectra. Carbon monoxide was used as an example. A new algorithm for gas concentration retrieval consisting of two ensemble methods is proposed. The first method uses an ensemble of local models based on linear and non-linear PLS (partial least square) regression algorithms, while the second is an ensemble of a calibration set built for different temperatures. It is possible to combine these methods to decrease the number of regression models in the first ensemble. These individual models are appropriate for specific measurement conditions specified by the ensemble of the calibration set. Model selection is based on comparison of gas spectra with values determined from each local model.
EN
This article presents the problem of determining the gas concentration under conditions of changing temperatures. The solution to this problem is based on spectral measurements using chemometric models. Such problems arise when measuring gases during various industrial processes, mainly the pyrolysis process. Chemometric models are built using synthetic calibration data. Line-by-line and statistical models were applied for spectra modelling. The effect of temperature on extracting the gas concentration from spectra of various resolutions was determined. Next, the global model was built and tested using calibration data for specific temperature ranges. The properties of the linear and nonlinear partial least-squares (PLS) models that were applied to the considered issues were demonstrated. CO and CH4 were used as example gases.
18
Content available remote Porous glasses with sodium nitrite impregnations
71%
EN
The properties of sodium nitrite introduced in porous glasses have been investigated. SEM graphs indicate existence of sodium nitrite inside glass pores. It has been shown that FTIR and Raman spectra are similar for bulk sodium nitrite and sodium nitrite embedded into porous glass. The nature of FTIR and Raman bands has been determined. The size-effect of sodium nitride introduced into porous glass was observed on the basis of dielectric measurements.
19
71%
EN
Solid and soluble products of THF and CH2Cl2 extraction of flame coal oxidised by four different oxidising agents (peroxyacetic acid (PAA), 5% HNO3, O2/Na2CO3, air/125 °C) were studied by elemental analysis and FTIR. The extraction yield with THF was much higher than that with CH2Cl2 for all samples. The greatest changes in elemental composition were in the extracts from coal oxidised by nitric acid. The sulphur content was lowest in extracts from coal oxidised with 5% HNO3 and PAA. FTIR confirmed that coal treatment with nitric acid incorporates nitrogen into the coal structure.
Open Chemistry
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2009
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tom 7
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nr 4
745-751
EN
The purpose of the present study is to synthesize hydroxyapatite by using CaCO3 and H3PO4 in various water-ethanol solvent systems. It was observed from experiments that formation of ammonium phosphate compounds hindered the formation of calcium phosphates in ethanol medium. Although the reactivity was better in aqueous medium, the carbonate contents of the products obtained were above 8.5%. Best results with a carbonate content as low as 3.82% was obtained in 50% ethanol containing mixed-aqueous medium at 80°C and the FTIR analysis showed that the product was a carbonated apatite with a calculated composition of 14CaO·4.2P2O5·CO3·7.2H2O. The amorphous and porous phosphate compound obtained with a BET surface area of 106.6 m2 g−1 seems to be useful as adsorbent in wastewater treatment. Upon sintering of the amorphous product at 750°C, crystalline hydroxyapatite with a BET surface area of 25.9 m2 g−1 is obtained that may be used in biomedical applications. [...]
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