Search results for "Spine"

Muscle Activity Adaptations to Spinal Tissue Creep in the Presence of Muscle Fatigue.

2016

Aim The aim of this study was to identify adaptations in muscle activity distribution to spinal tissue creep in presence of muscle fatigue. Methods Twenty-three healthy participants performed a fatigue task before and after 30 minutes of passive spinal tissue deformation in flexion. Right and left erector spinae activity was recorded using large-arrays surface electromyography (EMG). To characterize muscle activity distribution, dispersion was used. During the fatigue task, EMG amplitude root mean square (RMS), median frequency and dispersion in x- and y-axis were compared before and after spinal creep. Results Important fatigue-related changes in EMG median frequency were observed during m…

Afterglow, TL and OSL properties of Mn2+-doped ZnGa2O4 phosphor

2019

The work was supported by Latvian Research Council via LZP-2018/1–0214 research project as well as the Latvian-Ukrainian Joint Research Project (LV-UA/2016/1 in Latvia and M/8-2018 (No. 0118U001672) in Ukraine), and by the NATO SfP Project G4649. The work was also partially supported by the Polish National Science Center (project 2018/31/B/ST8/00774). A. Luchechko gratefully acknowledges a grant from Institute of Physics PAS for a research visit to the Institute.

Fast-neutron-induced and as-grown structural defects in magnesium aluminate spinel crystals with different stoichiometry

2019

Abstract Several hole-type paramagnetic defects (a hole localized at a regular oxygen ion near charged structural defect/defects) have been revealed in fast-neutron-irradiated MgO⋅2.5Al2O3 single crystals using the EPR method. Three of them (a dominant V1 and small amount of V2 and V22) were recently revealed in a neutron-irradiated stoichiometric MgAl2O4, while a novel V4 center, ascribed to a hole in a form of O− ion nearby a complex of a magnesium vacancy and a positively charged antisite defect (V4 ≡ O–‑VMg‑Al|Mg), was created by fast neutrons only in a nonstoichiometric single crystal. The pulse annealing of the EPR signal of these centers was compared to that of radiation induced opti…

Properties of Ni–Zn ferrite thin films deposited using spray pyrolysis

2012

Abstract Nanocrystalline, homogeneous spinel Ni 1 − x Zn x Fe 2 O 4 thin films were deposited on glass substrates by using spray pyrolysis of metal nitrate aqueous solutions. The thickness of deposited films was below 500 nm, but crystallite size was under 30 nm. It has been shown that the DC resistivity, dielectric loss and optical band gap of deposited films are influenced by the zinc content. High DC resistivity and low dielectric losses of thin Ni 1 − x Zn x Fe 2 O 4 films are explained by mixed n-p conductivity and nanograin structure of spray pyrolysis deposited coatings which are changing with the ratio of Ni/Zn.

61Ni MÖSSBAUER EFFECT STUDIES OF THE FERRIMAGNETIC SPINEL NiCr2O4 IN AN APPLIED MAGNETIC FIELD

1980

Spark plasma sintering of cobalt ferrite nanopowders prepared by coprecipitation and hydrothermal synthesis.

2007

International audience; Cobalt ferrite exhibits a high coercivity at room temperature and a strong magnetic anisotropy compared to the other spinel ferrites and, consequently appears as an interesting material for permanent magnets and high-density recording. The magnetic properties depend also on the crystallite size. In order to keep the powder properties in a bulk material, dense nanostructured cobalt ferrite has to be sintered. A field activated sintering process like spark plasma sintering (SPS) may be promising for such challenge. The present paper deals with: (i) the preparation of cobalt ferrite by two methods: coprecipitation and hydrothermal synthesis in supercritical water; (ii) …

Fabrication and characterization of ZnO/Zn2TiO4/ZnAl2O4 composite films by using magnetron sputtering with ceramic targets

2022

Abstract Transparent conducting oxides (TCO), including ZnO/Zn2TiO4/ZnAl2O4 composite films, are of considerable importance in optoelectronic applications. We fabricated composite film assisted with DC magnetron sputtering using ceramic target material (ZnO, TiO2, and Al2O3 powders mixture). The influence of processing gases composition (0–50% O2–Ar) on film characteristics, including structural, optical, and electronic properties, is assessed. All films contain hexagonal wurtzite ZnO structure and ZnAl2O4, Zn2TiO4 spinel phases, with (002), (100), and (101) as dominant orientation by increasing oxygen contents. The transmittance of deposited films is above 81% (except for 50% oxygen), and …

Mechanical activation conditions of the Fe2O3 and V2O3 mixture powders in order to obtain a nanometric vanadium spinel ferrite

1999

Abstract Co-milling of iron and vanadium oxides allows to obtain an intimate oxides mixture at a nanoscale, similar to a coprecipitate elaborated by soft chemistry. Reduction of such a mixture in the same temperature and oxygen partial pressure conditions (500°C and 10−25 Pa) as the soft chemistry products leads to a nanometric vanadium ferrite with the only spinel phase. The characterization of the powders is achieved by X-ray diffraction (XRD), scanning electron microscopy, infrared (IR) spectrometry, thermogravimetry and calorimetry. Homogeneity of grain size and chemical composition is reached if the initial oxides have similar grain size.

Evolution of the structural and optical properties from cobalt cordierite glass to glass-ceramic based on spinel crystalline phase materials

2007

Co 2+ -containing cordierite stoichiometric glasses have been prepared by melting colloidal gel precursors. After controlled thermal processing in the range of temperatures between 900 and 1300 C different polycrystalline, almost single phase materials displaying l-, a-, and b-cordierite crystalline forms were synthesized. In addition, spinel glass-ceramic materials were also prepared from the base glasses. All these materials were characterized by X-ray powder diffraction and infrared spectroscopy. Room temperature (RT) absorption and emission spectra of Co 2+ – cordierites and – spinel-glass material have allowed determining the local environment of the Co 2+ in the crystalline structure …

High pressure in-situ X-ray diffraction study on Zn-doped magnetite nanoparticles

2018

We have performed high pressure synchrotron X-ray powder diffraction experiments on two different samples of Zn-doped magnetite nanoparticles (formula Fe(3-x)ZnxO4; x = 0.2, 0.5). The structural behavior of then a noparticles was studied up to 13.5 GPa for x = 0.2, and up to 17.4 GPa for x = 0.5. We have found that both systems remain in the cubic spinel structure as expected for this range of applied pressures. The analysis of the unit cell volume vs. pressure results in bulk modulus values lower than in both end-members, magnetite (Fe3O4) and zinc ferrite (ZnFe2O4), suggesting that chemical disorder may favor compressibility, which is expected to improve the increase of the Neel temperatu…