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Wyszukujesz frazę "fourier transform infrared spectroscopy" wg kryterium: Temat


Tytuł:
Impact of Grape Variety, Yeast and Malolactic Fermentation on Volatile Compounds and Fourier Transform Infrared Spectra in Red Wines
Autorzy:
Stój, Anna
Czernecki, Tomasz
Sosnowska, Bożena
Niemczynowicz, Agnieszka
Matwijczuk, Arkadiusz
Powiązania:
https://bibliotekanauki.pl/articles/2019465.pdf
Data publikacji:
2022-03-01
Wydawca:
Instytut Rozrodu Zwierząt i Badań Żywności Polskiej Akademii Nauk w Olsztynie
Tematy:
fermentation
Saccharomyces cerevisiae
Saccharomyces bayanus
Oenococcus oeni
aroma compounds
Fourier transform infrared spectroscopy
Opis:
Volatile compounds are very important to the flavour and quality of the wine. The study aimed to determine the effect of grape variety (Rondo and Zweigelt), yeast, malolactic fermentation (MLF) and yeast×MLF interaction on the content of volatile compounds in red wines. The wines were produced by sequential inoculation with five commercial yeast strains and a commercial lactic acid bacteria (LAB) strain (induced malolactic fermentation) as well as by inoculation with five commercial yeast strains and without LAB inoculation (spontaneous malolactic fermentation). The volatile compounds were determined by headspace solid-phase microextraction/gas chromatography-mass spectrometry (HS-SPME-GC/MS). Forty-six volatile compounds belonging to alcohols, esters, acids, aldehydes, ketones, furan compounds, sulfur compounds and volatile phenols were identified in the wines. The grape variety was the factor with a significant impact on the highest number of volatile compounds, 32 out of 46. Furthermore, 7 compounds were affected by yeast, 10 by MLF and only 3 by yeast×MLF interaction. Characteristic bands in Fourier transform infrared (FTIR) spectra were assigned to the vibrations of functional groups of volatile compounds. The whole FTIR spectra were analysed in detail; three characteristic spectral ranges for different classes of volatile compounds such as 3650-2700, 1750-1500, and below 1500 cm-1 were shown. The most remarkable spectral changes were observed for the last two areas.
Źródło:
Polish Journal of Food and Nutrition Sciences; 2022, 72, 1; 39-55
1230-0322
2083-6007
Pojawia się w:
Polish Journal of Food and Nutrition Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Synthesis, spectroscopic and thermogravimetric interpretations of UO2(II), ZrO(II), Zr(IV), VO(II) and V(V) ciprofloxacin antibiotic drug complexes
Autorzy:
Albedair, Lamia A.
Powiązania:
https://bibliotekanauki.pl/articles/1849331.pdf
Data publikacji:
2021
Wydawca:
Zachodniopomorski Uniwersytet Technologiczny w Szczecinie. Wydawnictwo Uczelniane ZUT w Szczecinie
Tematy:
ciprofloxacin
complexation
FTIR
Fourier transform infrared spectroscopy
diamagnetic
TEM
transmission electron microscopy
nanoscale
Opis:
New five ciprofloxacin (CIP) complexes of dioxouranium(II), oxozirconium(II), zirconium(IV), oxovanadium(II) and vanadium(IV) in the proportion 1:2 have been prepared using CIP as a drug chelate with UO2(NO3)2. 6H2O, ZrOCl2. 8H2O, ZrC4, VOSO4. xH2O and V2O5 respectively. The CIP complexes have been characterized based on the elemental analysis, molar conductance, magnetic, (FTIR & 1HNMR) spectral and thermal studies. The molar conductance studies of the synthesized complexes in DMSO solvent with concentration of 10–3 M indicate their non-electrolytic properties. At room temperature, the magnetic moment measurements revealed a diamagnetic behavior for all CIP prepared complexes. The different formulas of the new complexes can be represented as [UO2(CIP)2(NO3)2] (I), [VO(CIP)2(SO4)(H2O)] (II), [V2(O)(O2)2(CIP)2] (III), [Zr(O)(CIP)2(Cl)2] (IV), and [Zr(CIP)2(Cl)4] (V). The thermal analysis data of the complexes indicates the absence of coordinated water molecules except for vanadyl(II) complex (II). The CIP chelate is a uni-dentate ligand coordinated to the mentioned metal ion through terminal piperazinyl nitrogen. The transmission electron microscopy (TEM) investigation confirms the nano-structured form of the complexes.
Źródło:
Polish Journal of Chemical Technology; 2021, 23, 1; 45-52
1509-8117
1899-4741
Pojawia się w:
Polish Journal of Chemical Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Mass spectrometry approaches in proteomic and metabolomic studies
Autorzy:
Rodziewicz, P.
Swarcewicz, B.
Chmielewska, K.
Powiązania:
https://bibliotekanauki.pl/articles/80650.pdf
Data publikacji:
2014
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
proteomics
metabolomics
genomic DNA
nuclear magnetic resonance
mass spectrometry
Fourier transform infrared spectroscopy
Raman spectroscopy
Źródło:
BioTechnologia. Journal of Biotechnology Computational Biology and Bionanotechnology; 2014, 95, 3
0860-7796
Pojawia się w:
BioTechnologia. Journal of Biotechnology Computational Biology and Bionanotechnology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Conformational changes in wheat gluten after using Ag-nanoparticles
Autorzy:
Nawrocka, A.
Powiązania:
https://bibliotekanauki.pl/articles/973221.pdf
Data publikacji:
2014
Wydawca:
Polska Akademia Nauk. Instytut Agrofizyki PAN
Tematy:
conformational change
wheat gluten
silver
nanoparticle
trisodium citrate
Fourier transform infrared spectroscopy
secondary structure
Opis:
Silver nanoparticles have antimicrobial properties since they can be regarded as an efficient protector against pathogenic microorganisms. Fourier transform infrared spectroscopy was used to examine conformational changes in the secondary structure of wheat gluten washed out from grain treated with an aqueous solution of silver nanoparticles stabilized by trisodium citrate. Silver nanoparticles were used as a protective layer on the grain surface against bacterial and fungal infections (antimicrobial agent). Analysis of the amide I band revealed significant changes in the secondary structure after using silver nanoparticles. An increase in the -sheet content (from 36.2 to 39.2%) was observed at the expense of the -helix and -turn content. To find factors causing these changes, the wheat grains were treated by an aqueous solution of trisodium citrate and water. The results obtained indicate that the changes in the gluten structure were connected mainly with the trisodium citrate action due to presence of a small number of free molecules of the stabilizer in the solution of silver nanoparticles. Additionally, the conformational changes in gluten pointed out that gluten flexibility increased (decrease in the H/S ratio from 1.40 for the control sample to 1.26 for the silver nanoparticle-treated samples) as well as the solubility of gluten decreased (decrease in the -turn content from 13.1 to 11.4%)
Źródło:
International Agrophysics; 2014, 28, 3
0236-8722
Pojawia się w:
International Agrophysics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Influence of thermal treatment on selected properties of chestnut wood and full range of its visual features
Autorzy:
Lo Monaco, Angela
Pelosi, Claudia
Agresti, Giorgia
Picchio, Rodolfo
Rubino, Gianluca
Powiązania:
https://bibliotekanauki.pl/articles/342665.pdf
Data publikacji:
2020
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Technologii Drewna
Tematy:
Castanea sativa Mill.
heat treatment
colour
surface properties
reflectance spectrophotometry
Fourier Transform Infrared spectroscopy
Opis:
The use of chestnut wood (Castanea sativa Mill.) is highly relevant in Central Italy, as it is one of the most important and abundant broad-leaf species in this geographical area. The comprehension of the modifications induced by thermal treatment is of crucial importance to define the optimal temperature that could improve the mechanical and physical properties without affecting significantly the visual appearance. In this paper a careful and complete investigation on the effect of thermal treatment on chestnut wood (Castanea sativa Mill.) is reported. The aim of this study is addressed to understand the chemical-physical modifications occurred on the surface of wood samples, as a consequence of heating, in order to choose the most suitable temperature of treatment, also in the view of applying a possible coating. No such complete and homogeneous study on chestnut wood was found in the literature, so this paper contributes to add relevant scientific and technological information on it. Samples of chestnut were thermally treated 6 hours in a conventional oven at 140°C, 170°C and 200°C. Surface properties of heated wood, in comparison with untreated, were evaluated through the measurements of: roughness, colour, Vickers and Brinell hardness, surface profile and contact angle. The behaviour of earlywood and latewood was evaluated by studying separately the effect of heating on contact angle and surface micro- -hardness. Fourier transform infrared spectroscopy was also used to evaluate the chemical modification of wood components due to thermal treatment. Heating at 140°C has little influence on wood characteristics whereas 200°C has a great impact on colour, mechanical properties and hydrophobicity behaviour. The intermediate temperature, i.e. 170°C, seems to give the best results in term of improved mechanical properties and also aesthetical appearance of wood surfaces.
Źródło:
Drewno. Prace Naukowe. Doniesienia. Komunikaty; 2020, 62, 205; 5-24
1644-3985
Pojawia się w:
Drewno. Prace Naukowe. Doniesienia. Komunikaty
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Changes of albumin secondary structure after palmitic acid binding : FT-IR spectroscopic study
Autorzy:
Oleszko, A
Hartwich, J.
Gąsior-Głogowska, M.
Olsztyńska-Janus, S.
Powiązania:
https://bibliotekanauki.pl/articles/307332.pdf
Data publikacji:
2018
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
kwas palmitynowy
albumina
spektrometria FTIR
palmitic acid
albumin
Fourier transform infrared spectroscopy
protein secondary structure
Opis:
Purpose: Albumin is an universal transport protein. Plasma pool of free fatty acids arising from triglyceride hydrolysis, critical in energy metabolism and etiology of metabolic disorders is transported by albumin. According to various studies albumin has from seven to nine binding sites with diverse affinity to long chain fatty acids. X-ray diffraction crystallography measurements have provided data only for pure human serum albumin or albumin with fully saturated binding sites. These results have shown that amount of -helices is higher after fatty acids binding. Molecular mechanics simulations suggest that binding of fatty acids in two high-affinity sites leads to major conformational changes in albumin structure. The aim of this research was to investigate albumin secondary structure upon gradually increasing fatty acids to protein mole ratio. Methods: Fourier transform infrared spectroscopy was applied to study changes of bovine serum albumin (as an analogue of human serum albumin) -helical structures after binding palmitic acid in a range of 0–20 palmitic acid: albumin molar ratios representing pure protein, partial, full saturation and excess binding sites capacity. Results: Amount of -helices was increasing along with the amount of palmitic acid: bovine serum albumin molar ratio and reached maximum value around 2 mol/mol. Conclusions: Our studies confirmed molecular mechanics simulations and crystallographic studies. Palmitic acid binding in two high-affinity sites leads to major structural changes, filling another sites only slightly influenced bovine serum albumin secondary structure. The systematic study of fatty acids and albumin interactions, using an experimental model mimicking metabolic disorders, may results in new tools for personalized nanopharmacotherapy.
Źródło:
Acta of Bioengineering and Biomechanics; 2018, 20, 1; 59-64
1509-409X
2450-6303
Pojawia się w:
Acta of Bioengineering and Biomechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Influences of operating parameters on dry ball mill performance
Autorzy:
Cayirli, S.
Powiązania:
https://bibliotekanauki.pl/articles/110047.pdf
Data publikacji:
2018
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
conventional ball mill
particle size
surface area
grinding aid
fluidity index
Fourier Transform Infrared Spectroscopy
Opis:
The paper is aimed to investigate the influence of operating parameters on dry fine grinding of calcite in a laboratory scale conventional ball mill. Within the context, the influence of operating parameters such as mill speed, ball filling ratio, ball size distribution, powder filling ratio, grinding aid dosage and grinding time were studied. The results of grinding tests were evaluated based on the product particle size (d50, d80) and surface area (m2/kg). As a result of this study, optimum grinding test conditions determined to be 70% of Nc, J=0.35 for ball filling ratio, 40 mm (10%), 32 mm (10%), 20 mm (40%), 12 mm (40%) for ball size distribution, fc=0.125 for powder filling ratio, 2000 g/Mg for grinding aid dosage and 60 min for grinding time. After determining optimum grinding conditions, the influence of grinding aid dosage on powder fluidity was determined. The use of 2000 g/Mg grinding aid dosage had a greater fluidizing effect compared to the other dosages and no aid condition (0 g/Mg). The influence of grinding aid on dry fine grinding of calcite was also examined by Fourier Transform Infrared Spectroscopy (FTIR). FTIR measurements indicated that grinding aid was adsorbed on the ground calcite particles surface.
Źródło:
Physicochemical Problems of Mineral Processing; 2018, 54, 3; 751-762
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Spektroskopia w podczerwieni w ocenie modyfikacji powierzchniowych mikroorganizmów
Autorzy:
Zdarta, A.
Gajewska, I.
Smułek, W.
Kaczorek, E.
Powiązania:
https://bibliotekanauki.pl/articles/273624.pdf
Data publikacji:
2016
Wydawca:
Roble
Tematy:
modyfikacja powierzchniowa mikroorganizmów
spektroskopia w podczerwieni
spektroskopia fourierowska
FTIR
surface modification of microorganisms
infrared spectroscopy
Fourier transform infrared spectroscopy
Opis:
Modyfikacje powierzchniowe mikroorganizmów są zmianami zachodzącymi na powierzchni komórek indukowanymi przez czynniki środowiskowe. Dzięki nim możliwa jest adaptacja drobnoustrojów do warunków otoczenia, która zapewnia im przetrwanie i efektywne wykorzystanie substratów metabolicznych. W przeprowadzonych analizach jako czynniki modyfikujące wykorzystano naturalne środki powierzchniowo czynne – saponiny. Surfaktanty te występują powszechnie w ekstraktach z różnych części roślin wyższych. W przedstawionych badaniach podjęto próbę oceny efektywności wykorzystania spektroskopii w podczerwieni w analizie modyfikacji właściwości powierzchniowych komórek mikroorganizmów zachodzących w wyniku dostępności określonych substratów w hodowli. Uzyskane wyniki potwierdzają, że spektroskopia FTIR może być stosowana jako metoda szybkiej i efektywnej identyfikacji zmian właściwości powierzchniowych bakterii.
Źródło:
LAB Laboratoria, Aparatura, Badania; 2016, 21, 4; 14-18
1427-5619
Pojawia się w:
LAB Laboratoria, Aparatura, Badania
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
In situ methanolic solvent synthesis, spectroscopic and thermogravimetric characterizations of three new transition metal complexes of trimethoprim drug
Autorzy:
Refat, Moamen S.
Al-Humaidi, Jehan Y.
El-Sayed, Mohamed Y.
Hassan, Reham F.
Powiązania:
https://bibliotekanauki.pl/articles/1849325.pdf
Data publikacji:
2021
Wydawca:
Zachodniopomorski Uniwersytet Technologiczny w Szczecinie. Wydawnictwo Uczelniane ZUT w Szczecinie
Tematy:
complexation
trimethoprim
transition metals
TGA
thermogravimetric analysis
FTIR
Fourier transform infrared spectroscopy
ESR
kinetic thermodynamic parameters
Opis:
Trimethoprim drug (TMP) complexes of copper (II), cobalt (II), and nickel (II) were prepared and discussed by using elemental analysis (C, H, N analysis), magnetic, molar conductance, FTIR, Raman spectroscopy, electron spin resonance (ESR) and UV-vis spectroscopy analyses. TMP drug coordinated as a tridentate ligand towards the respected three metal ions through two nitrogen atoms of amino groups and nitrogen atom of pyrimidine ring which flanked between –NH2 groups, these assignments confirmed by spectroscopic, magnetic, ESR and thermogravimetric analyses with formulas [Cu(TMP)(H2O)3]Cl2, [Co(TMP)(H2O)3]Cl2 and [Ni(TMP) (H2O)]Cl2. Copper (II) and cobalt (II) complexes have an octahedral geometrical structure included one TMP molecule, three coordinated water molecules and two uncoordinated chlorine atoms while, nickel(II)–TMP complex has a tetrahedral geometric configuration that involved one TMP molecule, one coordinated water molecule and two uncoordinated chlorine atoms. The activation energies and other kinetic thermodynamic parameters were estimated based on the employed of the Coats-Redfern and Horowitz-Metzger equations. The nano–structured form of the synthesized TMP complexes was confirmed dependent on the transmission electron microscopy (TEM).
Źródło:
Polish Journal of Chemical Technology; 2021, 23, 1; 60-67
1509-8117
1899-4741
Pojawia się w:
Polish Journal of Chemical Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The Behavior of Jordanian Oil Shale during Combustion Process from the El-Lajjun Deposit
Autorzy:
Gougazeh, Mousa
Alsaqoor, Sameh
Borowski, Gabriel
Alsafasfeh, Ashraf
Hdaib, Ismail I.
Powiązania:
https://bibliotekanauki.pl/articles/2173323.pdf
Data publikacji:
2022
Wydawca:
Polskie Towarzystwo Inżynierii Ekologicznej
Tematy:
El-Lajjun oil shale
combustion
X-ray diffraction
thermogravimetric
fourier transform infrared spectroscopy
X-ray fluorescence
Opis:
The results of X-ray diffraction, thermogravimetric and FTIR spectroscopy analyses of mineral composition indicated that the El-Lajjun oil shale is principally composed of calcite, quartz with minor amounts of kaolinite), gypsum, and apatite. The obtained oil shale ash products at 830 °C and 1030 °C are dominated by lime, quartz, anhydrite, portlandite, gehlenite, and amorphous phases. The TGA weight loss curves clearly indicate that it occurred in the temperature range from 310 to 650 °C. The decomposition of oil shale carbonates was detected above 750°C. The functional groups in the organic material of oil shale are dominated by the aliphatic hydrocarbons, the semi-ash of which had diverse structures of polycyclic aromatic hydrocarbons. The most intensive of combustion occurred in the temperature range of 400–750 °C. In this temperature range, about 75 wt.% was accounted for the total mass loss.
Źródło:
Journal of Ecological Engineering; 2022, 23, 8; 133--140
2299-8993
Pojawia się w:
Journal of Ecological Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Mycoremediation of Heavy Metals Contaminated Soil by Using Indigenous Metallotolerant Fungi
Autorzy:
Akram, Muhammad Bilal
Khan, Ibrar
Ur Rehman, Mujaddad
Sarwar, Abid
Ullah, Najeeb
ur Rahman, Shafiq
Aziz, Tariq
Alharbi, Metab
Alshammari, Abdulrahman
Alasmari, Abdullah F.
Powiązania:
https://bibliotekanauki.pl/articles/27315654.pdf
Data publikacji:
2023
Wydawca:
Zachodniopomorski Uniwersytet Technologiczny w Szczecinie. Wydawnictwo Uczelniane ZUT w Szczecinie
Tematy:
Mycoremediation
Heavy Metals Contaminated Soil
Korangi Industrial Estate
FTIR
Fourier Transform Infrared Spectroscopy
SEM
Scanning Electron Microscope
Opis:
The present study was aimed to identify the indigenous fungal strains which could possibly be applied to the bioremediation of heavy metal-contaminated soil. The contaminated soil samples of Korangi Industrial Estate Karachi were found to have total concentration of Cu 1.044 mgL1 , and Pb 0.631 mgL–1. A total of eight indigenous strains of the fungus were isolated and screened for bioremediation capacity from heavy metals-contaminated soil. For the bioremediation of Lead (Pb) these same indigenous eight fungal strains were used for biological remediation. All the fungal isolated with enhanced bioremediation capability were through phenotypic and genotypical characterization. The topology of the phylograms established that the fungal isolates used in this study were allocated to: K1 (Penicillium notatum), K2 (Aspergillus parasiticus), K3 (Aspergillus fumigatus), K4 (Aspergillus flavus), K5 (Aspergillus terries), K6 (Fusarium solani), K7 (Penicillium chrysogenum), K8 (Aspergillus niger), K9 (Penicillium piceum) and K10 (Penicillium restrictum). Thus, K8 fungal isolate was found to be more efficient with maximum bioremediation capacity, for copper and lead removal efficiency, and selected for FTIR and SEM to find out the uptake of Cu and Pb which of the functional groups are involved, and further to detect the effects of bioleaching of both heavy metals on to the surface of K8 fungus biomass. The current study indicates that indigenous fungal isolates could be used with high potency to remediate or clean up the heavy metals-contaminated soil either by the technique of in situ or ex-situ bioremediation.
Źródło:
Polish Journal of Chemical Technology; 2023, 25, 3; 1--13
1509-8117
1899-4741
Pojawia się w:
Polish Journal of Chemical Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Preparation, characterization and optimization of cross-linked fructosyltransferase aggregates for the production of prebiotic fructooligosaccharides
Autorzy:
Ademakinwa, A.N.
Ayinla, Z.A.
Omitogun, O.G.
Agboola, F.K.
Powiązania:
https://bibliotekanauki.pl/articles/81247.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
fructosyltransferase
Aureobasidium pullulans
fructooligosaccharide
prebiotic
statistical optimization
scanning electron microscopy
X-ray spectroscopy
Fourier transform infrared spectroscopy
biotransformation
chemometric analysis
Źródło:
BioTechnologia. Journal of Biotechnology Computational Biology and Bionanotechnology; 2018, 99, 4
0860-7796
Pojawia się w:
BioTechnologia. Journal of Biotechnology Computational Biology and Bionanotechnology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A comparison of methods for obtaining nanocellulose using acid and ionic liquid hydrolysis reactions
Autorzy:
Babicka, Marta
Ratajczak, Izabela
Dwiecki, Krzysztof
Powiązania:
https://bibliotekanauki.pl/articles/24072146.pdf
Data publikacji:
2019
Wydawca:
Szkoła Główna Gospodarstwa Wiejskiego w Warszawie. Wydawnictwo Szkoły Głównej Gospodarstwa Wiejskiego w Warszawie
Tematy:
1-butyl-3-methylimidazolium chloride
sulphuric acid(VI)
acid hydrolysis
ionic liquid hydrolysis
dynamic light scattering
fourier transform infrared spectroscopy
Opis:
A comparison of methods for obtaining nanocellulose using acid and ionic liquid hydrolysis reactions. In this study, two methods were compared, i.e. acid hydrolysis using sulphuric acid (VI) and ionic liquid hydrolysis using 1-methyl-3-butylimidazolium chloride to obtain nanocellulose from Sigmacell Cellulose Type 20. The efficiency of both processes was tested for weight loss of the material during the reaction. The study showed that much more material can be obtained using ionic liquid hydrolysis than using acid hydrolysis. A dynamic light scattering study was performed to determine material particle size before and after these processes. Particles of nanometric size were recorded only for cellulose after the reaction with an ionic liquid. In addition, Fourier transform infrared spectroscopy was performed to determine the chemical structure of the materials tested.
Źródło:
Annals of Warsaw University of Life Sciences - SGGW. Forestry and Wood Technology; 2019, 107; 19--23
1898-5912
Pojawia się w:
Annals of Warsaw University of Life Sciences - SGGW. Forestry and Wood Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Diagnostyka stanu eksploatacyjnego glikolowych cieczy niskokrzepnących użytkowanych w przemysłowych instalacjach wymiany ciepła
Diagnostics of the exploitative state of glycol coolants used in industrial heat exchange installations
Autorzy:
Mroczkowska, A.
Molenda, J.
Powiązania:
https://bibliotekanauki.pl/articles/257457.pdf
Data publikacji:
2011
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Technologii Eksploatacji - Państwowy Instytut Badawczy
Tematy:
ciecz niskokrzepnąca
wymienniki ciepła
starzenie eksploatacyjne
biocydy
dodatki przeciwkorozyjne
chromatografia gazowa
spektrometria FTIR
coolants
heat exchangers
exploitative ageing
biocides
anticorrosive additives
gas chromatography
Fourier transform infrared spectroscopy
Opis:
Za pomocą spektrometrii FTIR oraz chromatografii GC/MS zbadano składy chemiczne dwóch glikolowych cieczy niskokrzepnących: cieczy nieużytkowanej oraz pracującej w układzie chłodzenia pośredniego przez okres 6 miesięcy. Na podstawie porównania wyników przeprowadzonych analiz spektralnych i chromatograficznych stwierdzono znaczne zmiany jakościowe, co wskazuje na przydatność zastosowanych technik analitycznych do monitorowania stanu eksploatacyjnego glikolowych cieczy niskokrzepnących. Należy zwrócić uwagę na powstawanie nowych substancji, a w szczególności długołańcuchowych węglowodorów i estrów oraz obniżenie zawartości wielu składników pochodzących z dodatków uszlachetniających, w szczególności krzemianów, pełniących funkcję inhibitorów korozji oraz pochodnych penicyloaminy, będących biocydami. Zużywanie się w trakcie eksploatacji tych substancji prowadzić może do pogorszenia parametrów eksploatacyjnych cieczy niskokrzepnącej. W związku z powyższym niezbędne jest okresowe uzupełnianie komponentów cieczy, a optymalny czas takiej operacji można zidentyfikować na podstawie monitoringu składu jakościowego eksploatowanego płynu za pomocą spektrometrii w podczerwieni oraz chromatografii gazowej sprzężonej ze spektrometrią mas.
Chemical compositions of two glycol coolants, unused liquid, and another liquid working in an indirect cooling system for 6 months were tested by means of FTIR spectroscopy and GC-MS gas chromatography. Using the results of these tests, a comparison was made of the chromatographic and spectral analyses, and considerable qualitative changes were found, which indicates the utility of these analytical techniques for monitoring the exploitative state of glycol coolants. The formation of new substances, like long-chain hydrocarbons and esters, should be taken under consideration as well as the decrease of components derived from additives, like silicates, acting as corrosion inhibitors and penicillamine derivatives, which are biocides. Deterioration of these substances during operation may lead to the general deterioration of the coolants. Therefore, periodic replacement of coolant components is essential. The optimal time of the operation can be identified on the basis the qualitative composition monitoring of the exploited liquid by means of an FTIR spectrometer and GC-MS chromatograph.
Źródło:
Problemy Eksploatacji; 2011, 2; 277-287
1232-9312
Pojawia się w:
Problemy Eksploatacji
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Surface functionalization of poly(L-lactide-co-glycolide) membranes with amphiphilic poly(2-oxazoline) for guided tissue regeneration and treatment of bone tissue defects
Autorzy:
Tryba, A. M.
Krok-Borkowicz, M.
Paluszkiewicz, C.
Pamuła, E.
Powiązania:
https://bibliotekanauki.pl/articles/283890.pdf
Data publikacji:
2018
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Polskie Towarzystwo Biominerałów
Tematy:
poly (L-lactide-co-glycolide)
poly (ethylene glycol)
poly (2-oxazolines)
phase separation
Fourier transform infrared spectroscopy (FTIR)
osteoblast-like cells
guided tissue regeneration (GTR)
bone tissue engineering
Opis:
The main challenge of this research was to functionalize the surface of poly(L-lactide-co-glycolide) (PLGA) membranes with amphiphilic poly(2-oxazoline) (POx) in order to change PLGA chemical state and properties. Poly(2-oxazolines) are very powerful polymers, which thanks to active pendant groups can be easily functionalized with biologically active molecules or peptides. The membranes were prepared by dissolving PLGA, POx, and poly(ethylene glycol) (PEG, 1000 Da) in methylene chloride (DCM), followed by PEG leaching. POx molecules were preferentially adsorbed at the interface PLGA-POx-PEG thanks to affinity to both hydrophilic (PEG) and hydrophobic (PLGA) chains. The properties of the membranes were characterized with Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and wettability tests. Cytocompatibility of the materials in contact with osteoblast-like MG-63 cells was studied by evaluation of cell viability (Alamar-Blue test), live/dead and phalloidin/DAPI staining. The results show that the presence of POx influenced topography of the PLGA membranes, but did not have an impact on their wettability. All membranes were fo-und cytocompatible with model osteoblasts. Presence of POx resulted in better cell adhesion as shown by microscopic studies after fluorescence staining for nuclei and cytoskeleton actin filaments. In summary, one-step phase separation process between PLGA, PEG, and POx, dissolved in DCM followed by drying and PEG leaching resulted in cytocompatible PLGA membranes with immobilised POx, which might be considered for guided tissue regeneration technique in periodontology and in bone tissue engineering.
Źródło:
Engineering of Biomaterials; 2018, 21, 147; 16-20
1429-7248
Pojawia się w:
Engineering of Biomaterials
Dostawca treści:
Biblioteka Nauki
Artykuł

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