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Wyszukujesz frazę "spectroscopic characterization" wg kryterium: Wszystkie pola


Tytuł:
Spectroscopic Characterization of Titanium Alloy Surface in a Biological Medium
Autorzy:
Nouicer, E.
Benlahreche, F.
Nouicer, A.
Powiązania:
https://bibliotekanauki.pl/articles/1030371.pdf
Data publikacji:
2017-01
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
82.45.Bb
82.80.Fk
Opis:
This work is aimed to study the effect of a biological medium simulated body fluid on surface modification of titanium alloy Ti6Al4V. Electrochemical techniques and the Raman spectroscopy are used. Polarization curves, plotted at different scan rates (5, 1, 0.5, and 0.2 mV/s), show a large range of passivation (above 3000 mV), with no occurrence of transpassivation. The return sweep shows the negative hysteresis with the shift of the corrosion potential in the more noble direction. The corrosion current is generally very low. These observations clearly confirm the high stability of the TiO₂ passive film. The Raman spectroscopy shows that titanium dioxide formed consists of rutile phase. It was found that the scan rate has not a significant effect on the passivation phenomenon. However, it influences the corrosion potential and the current density. Electrochemical impedance spectroscopy allowed to establish the Nyquist diagrams and Bode around the equilibrium potential, and at different imposed potentials in the passivation field. The system behavior is not purely capacitive and so it is necessary to take in consideration the constant phase element. The impedance diagrams at different imposed potentials on the passivation field are composed only of a single loop.
Źródło:
Acta Physica Polonica A; 2017, 131, 1; 28-31
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Synthesis, spectroscopic characterization and antimicrobial evaluation of some (E)-N-(4-substitutedbenzylidene)-4-fluorobenzenesulfonamides
Autorzy:
Jayanthi, P.
Jesu Retna Raj, G.
Sekar, M.
Thanikachalam, V.
Powiązania:
https://bibliotekanauki.pl/articles/1113828.pdf
Data publikacji:
2017
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
4-fluorobenzenesulfonamide
Bauer-Kirby
IR spectra
NMR spectra
antimicrobial activities
Opis:
In the present study, six numbers of Schiff bases (1-6) have been synthesized by the condensation of 4-fluorobenzenesulfonamide and substituted aromatic aldehyde. The purities of these Schiff bases have been checked by their physical constants, IR, 1H NMR and 13CNMR spectral data. The antimicrobial activities of these Schiff bases have been evaluated using Bauer-Kirby method.
Źródło:
World News of Natural Sciences; 2017, 13; 101-112
2543-5426
Pojawia się w:
World News of Natural Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Synthesis and Spectroscopic Characterization of l-aspartic Acid Complexes with Metals of the Lanthanides Family
Autorzy:
Mohamed, M. E.
Powiązania:
https://bibliotekanauki.pl/articles/412075.pdf
Data publikacji:
2013
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
L-aspartic acid
Lanthanides (III) complexes
IR and NMR
Opis:
The complexes between l-aspartic acid and metals of lanthanide series (La3+, Pr3+, Eu3+, Gd3+) have been prepared and characterized using a variety of techniques including, infrared spectroscopy, 1H NMR, 13C NMR, elemental analysis and metal contents. The sought metal effect on the electronic environment of the chiral carbon and its neighbouring atoms was observed in case of Europium and Praseodymium. The 13C downfield shift indicates a lower electron density at the carbon with consequent downfield shift observed on the ?-H attached to it increasing its acidity.
Źródło:
International Letters of Chemistry, Physics and Astronomy; 2013, 6; 91-115
2299-3843
Pojawia się w:
International Letters of Chemistry, Physics and Astronomy
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Spectroscopic Characterization of Ethylenediamine-di(o-hydroxyphenyl)acetic Acid and its Complexes with Lanthanide(III) Ions
Autorzy:
Hnatejko, Z.
Lis, S.
Elbanowski, M.
Powiązania:
https://bibliotekanauki.pl/articles/1945635.pdf
Data publikacji:
1996-08
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
78.55.-m
42.62.Hk
78.40.Ha
78.40.-q
Opis:
Binding properties of ethylenediaminedi(o-hydroxyphenyl)acetic acid (EHPG) with lanthanide(III) ions were studied using spectroscopic methods. Luminescence intensity and lifetime of the Tb(III) ion were measured in a wide pH range in order to characterize the Ln-EHPG complexation. The calculated hydration number of the Tb-EHPG system proved the replacement of six water molecules by the EHPG ligand in the inner coordination sphere of Tb(III). Energy transfer from Tb(III) to Eu(III) in the Tb(III)-EHPG-Eu(III) system indicated an existence of only monomeric form of the Tb-EHPG complex. Analysis of the ^1H NMR and FTIR spectra of the EHPG ligand and its complexes with lanthanide(III) ions confirmed the hexadentate manner of EHPG complexation with the lanthanides. The system of Dy(III)-EHPG, showing a linear dependence of luminescence intensity (λ$\text{}_{em}$=578 nm) of Dy(III) on its concentration, in the range of 3.3×10-7 to 1×10-5 mol. l-1, can be applied for spectrofluorimetric determination of Dy(III).
Źródło:
Acta Physica Polonica A; 1996, 90, 2; 353-359
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The Needles of Aleppo Pine From the Province of Taza-Morocco – A Biomaterial of Great Potential
Autorzy:
Mahmoud, Rachid
Hjouji, Kaoutar
Mehdaoui, Imane
Saoudi Hassani, El Mokhtar
Ben Abbou, Mohamed
Majbar, Zineb
Taleb, Mustapha
Rais, Zakia
Powiązania:
https://bibliotekanauki.pl/articles/2202321.pdf
Data publikacji:
2023
Wydawca:
Polskie Towarzystwo Inżynierii Ekologicznej
Tematy:
Aleppo pine
pine needle
physicochemical characterization
spectroscopic characterization
adsorbent
biomaterial
essential oil
Opis:
The needles of the Aleppo pine (Pinus halepensis) (PA) are very abundant in the forest of the National Park of Tazekka (Ta-za-Morocco) and are unexploitable. Moreover, they constitute a potential danger because they facilitate the outbreak of wildfires. To solve this problem, we have considered turning these needles into a biomaterial that could be used as raw material for different uses, such as wastewater treatment. The biomaterial of the Aleppo pine is obtained from its needles which are harvested in spring, dried, cut, crushed, and sieved. The powder obtained is analyzed before and after the extraction of essential oil. The physicochemical and spectroscopic analyses show that this biomaterial is porous, hygroscopic, slightly acidic, moderately moist, and not very conducive. Its average density in the anhydrous state is 0.6. It is rich in carbon (79.91%) and oxygen (18.91%) in the form of aromatic compounds and ketone imprints; thus, relating the presence of cellulose, pectin, lignin, and hemicellulose. Its composition in mineral elements (Na, Mg, Ca, K, Cl, S) is deficient. Gas chromatography-mass spectrometry (GC-MS) analysis of the oils extracted from the needle powder relates that it is a complex mixture of bioactive compounds such as mono-terpenoid α and β-pinene hydrocarbons. These results show that our biomaterial can be used as an adsorbent in wastewater treatment and the extracted essential oils can be used in the pharmacological, agro-food field.
Źródło:
Journal of Ecological Engineering; 2023, 24, 1; 41--50
2299-8993
Pojawia się w:
Journal of Ecological Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Microwave Synthesis, spectroscopic characterization and DFT investigation of 4-(4-(2-(4-substitutedphenyl)-4-oxothiazolidin-3-yl)benzyl)oxazolidin-2-one derivatives
Autorzy:
Rosy, P. Jacquline
Kalyanasundaram, S.
Santhanalakshmi, K.
Muthukumar, S.
Powiązania:
https://bibliotekanauki.pl/articles/1182446.pdf
Data publikacji:
2017
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
2-arylthiazolidine
FT-IR
HOMO–LUMO
hyperpolarizability
Opis:
A series of some novel 4-(4-(2-(4-substitutedphenyl)-4-oxothiazolidin-3-yl)benzyl)oxazolidin-2-one (6-10) derivatives were designed and synthesized under microwave irradiation. The synthesized compound was purified by crystallization using ethanol. The structure of the synthesized compound was assigned on the basis of the spectral data. IR spectrum showed the expected absorption frequencies and signals of this compound. To identify the stable structure, conformational analysis was performed using B3LYP/6-31 G(d,p) level of calculation. For the stable conformer the bond parameters were calculated by the same basis set. Results obtained at this level of theory were used for a detailed interpretation of the FT-IR spectra. The energy gap of the molecule was found using HOMO and LUMO calculation. Atomic charges of the carbon, nitrogen and oxygen were calculated using same level of calculations. The optimized geometric parameters and the theoretical vibrational frequencies were found to be in good agreement with the corresponding experimental data and with the results found in the literature.
Źródło:
World Scientific News; 2017, 69; 122-142
2392-2192
Pojawia się w:
World Scientific News
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Structural and Spectroscopic Characterization of 1-(5-Bromothiophen-2-yl)-3-(4-nitrophenyl)prop-2-en-1-one: An Analysis of Electronic and NLO Properties
Autorzy:
Tamer, Ö.
Avcı, D.
Atalay, Y.
Powiązania:
https://bibliotekanauki.pl/articles/1204951.pdf
Data publikacji:
2014-08
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
31.15.E-
33.20.Ea
33.20.Lg
42.65.-k
67.80.Jd
Opis:
The molecular structure of 1-(5-bromothiophen-2-yl)-3-(4-nitrophenyl)prop-2-en-1-one with $C_{13}H_8BrNO_3S$ empirical formula was simulated using B3LYP and CAM-B3LYP levels of density functional theory. After BTNP was optimized on the ground state, its characterization was enhanced via IR, NMR and UV-vis spectroscopies. Conformational analysis was performed based on B3LYP level so as to find the stable conformers of BTNP. Electronic transitions were calculated, and the important contributions from the molecular orbitals to the electronic transitions were investigated. HOMO and LUMO energies were calculated, and obtained energies displayed that charge transfer occurs in BTNP. It was displayed that BTNP is an efficient NLO material due to the coplanar of phenyl-nitro group and carbonyl group. NBO analysis also proved that charge transfer, conjugative interactions and intramolecular hydrogen bonding interactions occur through BTNP.
Źródło:
Acta Physica Polonica A; 2014, 126, 3; 679-687
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Scleroderma citrinum melanin: isolation, purification, spectroscopic studies with characterization of antioxidant, antibacterial and light barrier properties
Autorzy:
Łopusiewicz, Łukasz
Powiązania:
https://bibliotekanauki.pl/articles/1156260.pdf
Data publikacji:
2018
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
Scleroderma citrinum
antibacterial
antioxidant
earthball
light barrier
melanin
Opis:
The aim of this study was to isolate and evaluate biological properties of raw and purified melanins isolated from Scleroderma citrinum. Native melanin was isolated from the gleba of fresh S. citrinum fruiting bodies by alkaline extraction. Obtained pigment was purifed by acid hydrolysis and washed by organic solvents. Chemical tests, FT-IR and Raman spectroscopy analysis were conducted to determine the melanin nature of the isolated pigments. UV-Vis, transmittance, total polyphenolic content and colour properties were evaluated. Antioxidant activity was determined using ABTS and antibacterial activity by a well diffusion method. The results of the study demonstrated that melanins isolated from S. citrinum had antioxidant, light barrier and antibacterial properties. A purified form of melanin offered better light properties and higher antioxidant activity than the raw form. Both melanins inhibited the growth of E. facealis and P. aeruginosa. This study revealed that S. citrinum may be considered as a promising source of natural melanin. Isolated pigments presented all the physical and chemical properties common to natural and synthetic melanins. Raw and purified melanins showed differences in chemical composition, antioxidant activity and light barrier properties. Results suggest that, melanins from S. citrinum possess remarkable therapeutic action and could be applied in the food, cosmetics and pharmaceutical industries.
Źródło:
World Scientific News; 2018, 94, 2; 115-130
2392-2192
Pojawia się w:
World Scientific News
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Synthesis, Spectroscopic Interpretations, and Antioxidant Efficiency of Two Vital Selenium Complexes
Autorzy:
Al-Khodir, F.
Powiązania:
https://bibliotekanauki.pl/articles/1030094.pdf
Data publikacji:
2017-10
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
nicotinamide
riboflavin
selenium
syntheses
characterization
antioxidant
Opis:
This paper aimed to synthesis, spectroscopic characterizations, and antioxidant assessment of two new selenium complexes with nicotinamide (Nic) and riboflavin (RF) as drug chelates. The speculated structures of the synthetic selenium complexes have been discussed by using different tools of spectroscopic analyses like infrared, the Raman, electronic, ¹H-NMR, and mass. Accordingly, the Fourier transform infrared and ¹H-NMR spectra, the mode of complexation is supported, as four molecules of nicotinamide drug act as a monodentate chelate through the N-atom of the pyridine ring with [Se(Nic)₄]·H₂O formula. The two riboflavin drug molecules coordinated to selenium metal as a bidentate chelate through azomethine nitrogen of pyrazine ring and O-atom of C=O pyrimidine-2,4-dione group with general formula [Se(RF)₂]. Both of Nic and RF chelates act as neutral charge ligands. The conductivity measurements indicated that the selenium complexes are non-electrolytes behaviors. Thermal analyses (thermal gravimetric-differential thermal analysis) of the studied complexes show that the decomposition process takes place in one broadening step with a wide temperature range. The surface morphology of the mentioned complexes was studied by scanning electron microscope and the particle size is calculated using X-ray powder diffraction. Thermodynamic kinetic parameters are calculated by using the Coats and Redfern equation. Screening of antioxidant activities of selenium complexes in vitro are assessed. The antioxidant activity is studied by three methods (DPPH assay, β-carotene/linoleic acid bleaching assay, and ferric reducing power assay), the studied complexes have a significant antioxidant activity compared to synthetic antioxidants like trolox and BHT.
Źródło:
Acta Physica Polonica A; 2017, 132, 4; 1265-1271
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Characterization of optical and electrical properties of transparent conductive boron-doped diamond thin films grown on fused silica
Autorzy:
Bogdanowicz, R.
Powiązania:
https://bibliotekanauki.pl/articles/221053.pdf
Data publikacji:
2014
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
CVD
boron-doped diamond
optical properties
optical coatings
spectroscopic ellipsometry
Opis:
Abstract A conductive boron-doped diamond (BDD) grown on a fused silica/quartz has been investigated. Diamond thin films were deposited by the microwave plasma enhanced chemical vapor deposition (MW PECVD). The main parameters of the BDD synthesis, i.e. the methane admixture and the substrate temperature were investigated in detail. Preliminary studies of optical properties were performed to qualify an optimal CVD synthesis and film parameters for optical sensing applications. The SEM micro-images showed the homogenous, continuous and polycrystalline surface morphology; the mean grain size was within the range of 100-250 nm. The fabricated conductive boron-doped diamond thin films displayed the resistivity below 500 mOhm cm-1 and the transmittance over 50% in the VIS-NIR wavelength range. The studies of optical constants were performed using the spectroscopic ellipsometry for the wavelength range between 260 and 820 nm. A detailed error analysis of the ellipsometric system and optical modelling estimation has been provided. The refractive index values at the 550 nm wavelength were high and varied between 2.24 and 2.35 depending on the percentage content of methane and the temperature of deposition.
Źródło:
Metrology and Measurement Systems; 2014, 21, 4; 685-698
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł

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