Processes of removing zinc from water using zero-valent iron

Zero-valent iron has received considerable attention for its potential application in the removal of heavy metals from water. This paper considers the possibility of removal of zinc ions from water by causing precipitates to form on the surface of iron. The chemical states and the atomic concentrations of solids which have formed on the surface of zero-valent iron as well as the type of the deposited polycrystalline substances have been analyzed with the use of X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD), respectively. The BET surface area, the pH at point of zero charge (pHPZC), the ORP of the solutions, and the pH and chemical concentrations in the solutions have also been measured. Furthermore, the paper also considers the possibility of release of zinc from the precipitates to demineralised water in changing physicochemical and chemical conditions. In a wide range of pH values, Zn x Fe3 − x O4 (where x ≤ 1) was the main compound resulting from the removal of zinc in ionic form from water. In neutral and alkaline conditions, the adsorption occurred as an additional process

Electronic structure of CePtIn and LaPtIn compounds

The electronic structure of the ternary RPtIn (R = La, Ce) compounds, which crystallize in the hexagonal ZrNiAl-type structure, was studied by X-ray photoelectron spectroscopy measurements and calculation using the ab initio methods (linear mu n-tin orbital in the atomic sphere approximation, full potential linear mu n-tin orbital, full potential linear orbital). The results showed that the valence band in these compounds is formed by the Pt 5d and In 5s and 5p states. The band calculations with spin orbit coupling have shown that the Ce 4f peaks consist of two peaks above the Fermi level that correspond to the Ce 4f7=2 and 4f5=2 doublet and wide peaks corresponding to the La 4f states. The analysis of Ce 3d spectra on the basis of the Gunnarsson Schönhammer model gives hybridization of 4f orbitals with the conduction electron band equal to 170 meV

Electronic structure of CePtIn and LaPtIn compounds

The electronic structure of the ternary RPtIn (R = La, Ce) compounds, which crystallize in the hexagonal ZrNiAl-type structure, was studied by X-ray photoelectron spectroscopy measurements and calculation using the ab initio methods (linear mu n-tin orbital in the atomic sphere approximation, full potential linear mu n-tin orbital, full potential linear orbital). The results showed that the valence band in these compounds is formed by the Pt 5d and In 5s and 5p states. The band calculations with spin orbit coupling have shown that the Ce 4f peaks consist of two peaks above the Fermi level that correspond to the Ce 4f7=2 and 4f5=2 doublet and wide peaks corresponding to the La 4f states. The analysis of Ce 3d spectra on the basis of the Gunnarsson Schönhammer model gives hybridization of 4f orbitals with the conduction electron band equal to 170 meV

XPS Study of Superconducting LiTi2O4 and LiTi2-xCuxO4 Sol-Gel Derived Powders and Thin Films

In this work X-ray photoelectron studies of lithium titanate and copper doped lithium titanate are presented. Both, powder and thin lms samples were prepared by sol gel method. After preparation, the samples were heated in argon atmosphere at various temperatures in a range from 500 ◦C to 600 ◦C for 20 h. The crystalline structure of the samples was investigated by X-ray di raction, while the oxidation states of the elements were examined by X-ray photoelectron spectroscopy method. X-ray di raction measurements con rmed spinel phase of all manufactured samples. However it is well known that electrical and superconducting properties of lithium titanate are strongly correlated not only with structure, but also with oxidation state of Ti ions. X-ray photoelectron spectroscopy investigations revealed mixture of Ti3+ and Ti4+ ions, although the Ti3+/Ti4+ ratio is much smaller than 1 2 needed for superconductivity. In this work dependence between calcination temperature as well as amount of Cu dopant and Ti3+/Ti4+ proportion are reported

Breakdown of the de Gennes scaling in Y1-xDyxNi2B2C

Single crystals of Y1-xDyxΝi2B2C (1 ≤ x≤ 0.7) were examined by X-ray diffraction and stoichiometry was attested by XPS measurements. The superconducting transition temperature T^ and Neel temperature TN were determined by means of magnetisation measurements. A dramatic breakdown of the de Gennes scaling in the Dy-rich compounds was found when < TN

Mixed-valence state in Yb2CuGe6

We present here temperature dependent X-ray photoemission measurements on polycrystalline Yb2CuGe6. The analysis of these data shows the change in the effective valence, determined directly from the 4f intensity ratio, as a function of temperature

Superconducting properties of VN-SiO 2 sol-gel derived thin films

In this work studies of structure and superconducting properties of VN SiO2 lms are reported. The lms were obtained through thermal nitridation (ammonolysis) of sol gel derived V2O3 SiO2 coatings (in a proper V2O3/SiO2 ratio) at 1200 ◦ C. This process leads to the formation of disordered structure with VN metallic grains dispersed in the insulating SiO2 matrix. The structural transformations occurring in the lms as a result of ammonolysis were studied using X-ray photoelectron spectroscopy (XPS). The critical superconducting parameters are obtained. The magnetoresistance at high magnetic elds has been investigated

Crossover from Ferroelectric to Relaxor Behavior in Ba1−xCaxTiO3 (x = 0.17) System

The dielectric properties of Ba1xCaxTiO3 (x = 0.17) ceramics were studied in a wide frequency range of 20 Hz–53 GHz. Di used ferroelectric phase transition was revealed close to 339 K in the dielectric properties of ceramics. The behaviour of distributions of relaxation times in vicinity of the ferroelectric phase transition temperature is also typical for order-disorder ferroelectric phase transition. However, at lower temperatures (below 200 K), the most probable relaxation increased according to the Arrhenius law. At lower temperatures the maximum of the imaginary part of dielectric permittivity versus temperature strongly shifted to higher temperatures when the frequency increased (from 125 K at 1.21 kHz to 300 K at 33 GHz). This behaviour was attributed to the dynamics of Ti ions. The origin of the crossover from ferroelectric to relaxor behaviour of Ba1xCaxTiO3 (x = 0.17) ceramics is discussed in the paper

Some complementary data about the spectroscopic properties of manganese ions in spodumene crystals

The color change of the pink and colorless LiAlSi2O6 spodumene crystal due to irradiation and heating is explained. The hypothesis about the change of Mn3+ to Mn4+ after irradiation was rejected. For the studied crystals, it was shown that both Mn2+ and Mn3+ occupy the M2 (not the M1) crystal site. Spodumene crystals which are primary pink (kunzite) contain Mn3+ (and Mn2+) at the M1 site. By contrast, those that become pink due to irradiation and heating contain Mn3+ and Mn2+ at the M2 site. The emission band of the former is 625 nm, and for the latter, it is 591 nm

Ankieta na temat reformy ordynacji wyborczej do sejmu i senatu

Digitalizacja i deponowanie archiwalnych zeszytów RPEiS sfinansowane przez MNiSW w ramach realizacji umowy nr 541/P-DUN/201