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1

EPR and optical properties of KYb(WO4)2 and KTb0.2Yb0.8(WO4)2 single crystals

100%

Kaczmarek S., Macalik L., Fuks H., Leniec G., Skibiński T., Hanuza J.

Open Physics

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2012

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vol. 10

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issue 2

492-499

EN

Well oriented KYb(WO4)2 and KTb0.2Yb0.8(WO4)2 single crystals have been investigated for their magnetic and optical properties using the Raman and EPR techniques. The registered EPR signal is dominated by three lines ascribed to ytterbium ions: one main and two satellites. Tb ions, although non-paramagnetic, distinctly modify magnetic properties of the KYb(WO4)2 single crystal. Basic parameters of the spin Hamiltonian, including Zeeman and hyperfine terms (g and A matrices) as well the spatial orientation between principal and crystallographic axes systems were determined for both crystals.

2

Reversible electron charge transfer in single-wall carbon nanotubes

100%

Costa S., Bachmatiuk A., Borowiak-Palen E.

Polish Journal of Chemical Technology

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2008

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vol. 10

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issue 2

1-4

EN

Single-wall carbon nanotubes (SWCNT) have proved to be very special materials due to their unique electronic properties. Over the last years many scientists have dedicated their research to the study of the these materials as an electronic system. Amphoteric doping effects (n-type and p-type), which can be reversed, became a very popular way of manipulating the optic and electronic properties of carbon nanotubes. In the particular case of SWCNT, the most common and widely used procedure, which changes their properties, is acid treatment applied as a purification procedure. The effect of the addition of this kind of the dopant has been widely studied but not fully understood so far. Here, we present a study, of two kinds of SWCNT, produced within different techniques: (i) chemical vapors deposition and (ii) laser ablation. The main difference between the two types is the diameter distribution of the obtained materials, which is broad in the first technique and narrow in the second. After the acid treatment it is possible to observe a diameter sensitive doping effect on both samples. Resonance Raman spectroscopy, optical absorption spectroscopy (OAS) in UV/Vis/NIR and the Fourier transform middle-infrared (FTIR) spectroscopy have been applied for the characterization of the samples.

3

Study of diamond film nucleation by ultrasonic seeding in different solutions

88%

Varga M., Ižák T., Kromka A., Veselý M., Hruška K., Michalka M.

Open Physics

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2012

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vol. 10

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issue 1

218-224

EN

In this study we have investigated diamond nucleation on Si substrates by ultrasonic seeding with different liquid solutions of Ultradispersed Detonation Diamond (UDD) powder in a mixture of metal nano- or microparticles (Ni, Co, Y). The influence of different solutions on nucleation efficiency was investigated. For highlighting nucleation centers and better evaluation of the nucleation process the nucleated samples were moved into a Microwave Plasma Enhanced Chemical Vapor Deposition (MW CVD) reactor and a ”short-time” (10 min), then followed by a ”long-time” (+1 hour), diamond deposition was performed. The morphology of samples was characterized by Scanning Electron Microscopy (SEM) and the chemical composition of grown diamond layer was investigated by Raman Spectroscopy. From the measurements we found out that microsized metal particles positively influenced nucleation and the uniformity of the deposited diamond thin film. The lowest surface roughness was achieved in the case of nanodiamond powder mixed with Co and Y metal powder. The influence of Ni, Co and Y to the nucleation and early growth stage are discussed.

4

SERS approach for Zn(II) detection in contaminated soil

88%

Szabó L., Leopold L., Cozar B., Leopold N., Herman K., Chiş V.

Open Chemistry

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2011

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vol. 9

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issue 3

410-414

EN

Soil contamination by metals is a common problem encountered in many industrialized countries. In this work we present a new approach for heavy metals detection by using surface-enhanced Raman scattering (SERS) spectroscopy. Zn(II) can be clearly determined by SERS in contaminated soil by using 4-(2-pyridylazo) resorcinol (PAR) as chelating molecule for the metal ion. The SERS spectra of PAR, of its metal chelates and of the soil extract-PAR mixture were recorded using a hydroxylamine reduced silver colloid. An excellent match of the PAR-contaminated soil extracts SERS spectrum to the Zn(PAR)2 SERS spectrum can be observed, demonstrating the presence of Zn(II) in the soil probes. Density functional theory (DFT) based calculations were also performed for a reliable assignment of SERS spectra.

5

THE POSSIBILITY OF USING X-RAY POWDER DIFFRACTION, INFRARED AND RAMAN SPECTROSCOPY IN THE STUDY OF THE IDENTIFICATION OF STRUCTURAL POLYMORPHS OF ACETAMINOPHEN

88%

Stasiłowicz A., Mizera M., Tykarska E., Lewandowska K., Miklaszewski A., Cielecka-Piontek J.

Acta Poloniae Pharmaceutica - Drug Research

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2019

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vol. 76

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issue 6

997-1004

EN

Paracetamol (acetaminophen), a pain-killer with antipyretic properties, shows structural polymorphism. It occurs in three polymorphic forms: monoclinic, orthorhombic, and unstable form III. In the study, the commercially available samples of paracetamol (P1 and P2) were examined using X-ray powder diffraction, infrared, and Raman spectroscopy. Results demonstrated that all of the methods defined polymorphic forms of paracetamol in the samples. However, only Raman spectroscopy and PXRD methods detected impurities in the sample P1. These methods transpired to be more sensitive than the FT-IR method, which identified samples of paracetamol as one structural form (monoclinic polymorph). Moreover, the Raman spectroscopy identified impurities in the form P1 as changes in the crystalline form.

6

Physico chemical properties of irradiated i-SANEX diluents

75%

Mossini E., Macerata E., Giola M., Brambilla L., Castiglioni C., Mariani M.

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issue 4

893-898

EN

The development of effective processes to recover minor actinides from spent nuclear fuel cannot leave out of consideration the evaluation of the impact of ionizing radiations on safety, fluid dynamics and extraction efficiency. It is common knowledge from the literature that radiation damage mainly affects the diluents and, indirectly, the extractants [1], but a lack of knowledge remains regarding the radiolytic behavior of innovative selective actinide extraction (i-SANEX) diluents [2, 3]. As natural prosecution of the work already performed on diluted nitric acid solutions [4], 0.44 M nitric acid solutions were irradiated in contact with a mixture of kerosene + 5 vol.% 1-octanol by a Co-60 source at 2.5 kGy/h dose rate and up to 100 kGy absorbed dose, conditions of interest for the future industrial facility. Density, viscosity, acidity, nitrate anion concentration and phase transfers were systematically measured before and after γ-irradiation. This was performed because radiation-induced modifications of these parameters may induce alterations of both the fluid dynamics and the separation performances of the extracting system. The results suggest that the fluid-dynamics of the system should be unaltered. In fact, only slight alterations of the organic phase viscosity and of the aqueous phase acidity were measured after irradiation, suggesting the occurrence of limited phase transfers and of diluent by-products formation.

Refine search results

EPR and optical properties of KYb(WO4)2 and KTb0.2Yb0.8(WO4)2 single crystals

Reversible electron charge transfer in single-wall carbon nanotubes

Study of diamond film nucleation by ultrasonic seeding in different solutions

SERS approach for Zn(II) detection in contaminated soil

THE POSSIBILITY OF USING X-RAY POWDER DIFFRACTION, INFRARED AND RAMAN SPECTROSCOPY IN THE STUDY OF THE IDENTIFICATION OF STRUCTURAL POLYMORPHS OF ACETAMINOPHEN

Physico chemical properties of irradiated i-SANEX diluents