Search results for " solution"
showing 10 items of 3084 documents
Zn(II) and Ni(II) complexes with poly-histidyl peptides derived from a snake venom
2018
Abstract The snake venoms are complex mixtures containing many bioactive peptides and proteins; some of them are aimed to protect the snake glands, where the venom is stored, until the latter is inoculated in the victim. In the venom of some vipers of the genus Atheris , a set of peptides containing poly-His and poly-Gly segments was recently found. Poly-His peptides are not rare in Nature. Although their exact biological function is most often unknown, one thing is certain: they have good binding properties towards the transition metal ions. As a matter of fact, the imidazole side chain of histidine is one of the groups most frequently involved in metal complexation in the active sites of …
On the structural aspects of solid solutions of enantiomers: an intriguing case study of enantiomer recognition in the solid state
2018
Structural aspects of solid solutions of enantiomers have been considered and the corresponding definitions of type 1 and type 2 solid solutions have been revised based on the available structures reported in the literature. Examples of both types are presented indicating that (e.g., type 1 solid solutions) there is a straightforward relationship between the particular structural aspects and the enantiomer miscibility limits in the solid state. Furthermore, enantiomer recognition in a type 2 solid solution formed by the enantiomers of a pharmaceutically active ingredient, pimobendan, has been studied in more detail. It was found that upon rapid crystallization from a solution a structure po…
Behaviour of thermal expansion of (1-x)Pb(Ni1/3Nb2/3)O3–xPbTiO3 solid solutions
2017
The publication costs of this article were covered by the Estonian Academy of Sciences and the University of Tartu.
On the Phase Separation in n-Type Thermoelectric Half-Heusler Materials
2018
Half-Heusler compounds have been in focus as potential materials for thermoelectric energy conversion in the mid-temperature range, e.g., as in automotive or industrial waste heat recovery, for more than ten years now. Because of their mechanical and thermal stability, these compounds are advantageous for common thermoelectric materials such as Bi 2 Te 3 , SiGe, clathrates or filled skutterudites. A further advantage lies in the tunability of Heusler compounds, allowing one to avoid expensive and toxic elements. Half-Heusler compounds usually exhibit a high electrical conductivity σ , resulting in high power factors. The main drawback of half-Heusler compounds is their high lattice th…
Crystal chemical characterization of mullite-type aluminum borate compounds
2017
Abstract Al-rich aluminum borates were prepared by different synthesis routes using various Al/B ratios, characterized by diffraction methods, spectroscopy and prompt gamma activation analysis. The 11B NMR data show a small amount of BO4 species in all samples. The chemical analysis indicates a trend in the Al/B ratio instead of a fixed composition. Both methods indicate a solid solution Al5−xB1+xO9 where Al is substituted by B in the range of 1–3%. The structure of B-rich Al4B2O9 (C2/m, a=1488 pm, b=553 pm, c=1502 pm, s=90.6°), was re-investigated by electron diffraction methods, showing that structural details vary within a crystallite. In most of the domains the atoms are orderly distrib…
Dismantling and electrochemical copper recovery from Waste Printed Circuit Boards in H2SO4–CuSO4–NaCl solutions
2019
Abstract The worldwide growing of electrical and electronic equipment makes increasingly urgent to find environmentally friendly treatments for e-waste. In this paper, the attention has been focused on i) the eco-friendly dismantling of the electronic components from Waste Printed Circuit Boards and ii) recovering of pure metallic copper, which is the most abundant metal and one of the most valuable in Printed Circuit Boards. After an experimental optimization study, we found that a solution containing 0.5 M H2SO4, 0.4 M CuSO4, and 4 M NaCl can be successfully used to disassemble the electronic components from the boards by leaching of all exposed metals. Air was blown into the leaching sol…
Proton sponge lead halides containing 1D polyoctahedral chains
2021
Hybrid one-dimensional lead halides, containing the protonated 1,8-bis(dimethylamino)naphthalene moiety (C14H19N2, monoprotonated "proton sponge"), were prepared by simple one-pot methods and investigated in terms of crystal structure, morphology, thermal stability and electronic properties. The as-precipitated (C14H19N2)PbBr3 and (C14H19N2)PbI3 species are isostructural and crystallize in the orthorhombic Pbca space group, resulting in 1D crystal phases with ([PbX3](-))(infinity) chains (built by face-sharing [PbX6] octahedra; X = Br, I), among which the (C14H19N2)(+) cations are inserted. The two compounds display complete miscibility in the solid state: both (C14H19N2)PbI2Br and (C14H19N…
One-step electrodeposition of superhydrophobic coating on 316L stainless steel
2021
Superhydrophobic coatings were fabricated through a one-step electrochemical process onto the surface of 316L stainless steel samples. The presence of hierarchical structures at micro/nanoscale and manganese stearate into the coatings gave superhydrophobicity to the coating, with contact angle of ~160°, and self-cleaning ability. Corrosion resistance of 316L samples was also assessed also after the electrodeposition process through Electrochemical Impedance Spectra recorded in an aqueous solution mimicking seawater condition.
Theoretical and Experimental Study of (Ba,Sr)TiO 3 Perovskite Solid Solutions and BaTiO 3 /SrTiO 3 Heterostructures
2019
This study was supported by the ERA-NET HarvEnPiez project. The authors would like to thank their national funding agencies (Latvian State Education Development Agency, Slovenian Ministry of Higher Education, Science and Technology, Romanian National Authority for Scientific Research and Innovation, CCCDI-UEFISCDI, project number 49/2016 within PNCDI III – M-ERA NET Program).
Influence of cation order on the dielectric properties of (1 – x)Pb(Sc 0:5 Nb 0:5 )O 3 -xPb(Yb 0:5 Nb 0:5 )O 3 ceramics
2020
Ceramic lead niobates and their solid solutions (1 - x)Pb(Sc0:5Nb0:5)O3 - xPb(Yb0:5Nb0:5)O3 were synthesized by solid state reactions from oxides. The structure of investigated samples was characterized by X-ray diffraction (XRD). Dielectric studies of the ceramics were performed by means of broadband dielectric spectroscopy at the temperature ranging from 600 K to 140 K. For all ceramic samples a diffuse phase transition as well as relaxor ferroelectric behavior were observed. © 2020 Barbara Garbarz-Glos et al., published by Sciendo 2020. This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.