Effect of Structural Relaxation on the In-Plane Electrical Resistance of Oxygen-Underdoped ReBa_2Cu_3O_{7-\delta } (Re = Y,Ho) Single Crystals

The effect of jumpwise temperature variation and room-temperature storing on the basal-plane electrical resistivity $\rho _{ab}$ of underdoped ReBa $_2$ Cu $_3$ O $_{7-\delta }$ (Re = Y, Ho) single crystals is investigated. Reducing the oxygen content has been revealed to lead to the phase segregation accompanied by both, labile component diffusion and structural relaxation in the sample volume. Room-temperature storing of ${\text {YBa}}_2{\text {Cu}}_3{\text {O}}_{7-\delta }$ single crystals with different oxygen hypostoichiometries leads to a substantial widening of the rectilinear segment in $\rho _{ab}(T)$ in conjunction with a narrowing of the temperature range of existence of the pseudogap state. It is established that the excess conductivity obeys an exponential law in a broad temperature range, while the pseudogap’s temperature dependence is described satisfactory in the framework of the BCS-BEC crossover theory. Substituting yttrium with holmium essentially effects the charge distribution and the effective interaction in CuO planes, thereby stimulating disordering processes in the oxygen subsystem. This is accompanied by a notable shift of the temperature zones corresponding to transitions of the metal-insulator type and to the regime of manifestation of the pseudogap anomaly.     

Motion and Detachment Behaviors of Liquid Inclusion at Molten Steel–Slag Interfaces

Metallurgical and Materials Transactions B - The fundamental physics of particles adsorbed at the liquid interfaces has numerous applications in a wide field. In the current study, the motion and...     

Stabilization of polymers of vinylchloride with sulfur

The high stabilizing efficiency of element sulfur was revealed by the thermooxidative destruction of polymers of vinylchloride (VC). It was shown that the stabilizing efficiency of sulfur in compositions of polymers of VC is comparable with the efficiency of phenolic antioxidants. Element sulfur inhibits process of autooxidation of esters‐plastifiers of polymers of VC, apparently, because of destruction of formed hydroperoxides. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 4538–4542, 2006     

Review of solid/liquid desiccant in the drying applications and its regeneration methods

Desiccant material has been used in drying applications because of its low energy consumption, among other advantages. Desiccant material can produce hot and dry air that is beneficial for the drying process. The advantages of using desiccant material in a drying system include continuous drying even during off-sunshine hours, increased drying rate due to hot and dry air, more uniform drying, and increased product quality especially for heat-sensitive products. Some problems in desiccant system such as pressure drop in solid desiccant, carry over of liquid desiccant by air stream and low moisture adsorption capacity may be improved by optimization of the design of desiccant system. Numerous researchers have studied the low cost and low regeneration temperature of desiccant material, and the optimization of desiccant application to produce more competitive energy. The use of heat to regenerate desiccant material in a drying system has limitations in energy saving. However the use of low energy or free available energy such as solar energy and waste heat from industrial processes for regeneration of desiccant material will make the system more cost-effective. This paper presents several works on the regenerative method of the desiccant system and its application in the drying system for both solid and liquid desiccant materials.     

Synthesis and transport properties of prospective photovoltaic systems related to CuInSe2 and CuGaSe2

Solid solutions in CuGaSe₂–ZnSe and CuInSe₂–ZnSe systems have been obtained by radio frequency heating. In order to prepare n-type phases based on CuGaSe₂, p-type (CuGa)_1−xZn_2xSe₄ and (CuIn)_1−xZn_2xSe₄ (0.05x0.1) single crystals were doped by Ag, Hg, Cd, Zn implantation. The crystal structure of the solid solutions was studied by X-ray diffraction; the substitutors as well as the implantant valence states were analyzed using X-ray photoelectron spectroscopy. Hall effect, electrical conductivity, and the charge carrier mobility of an n-type zinc-implantated solid solution (CuGa)_1−xZn_2xSe₄ and (CuIn)_1−xZn_2xSe₄ (0.05x0.1) were studied.     

Surface chemistry of the titanium powder studied by XPS using internal standard reference

Surface chemistry of the titanium powder has particularly growing interest due to the increasing application of titanium components prepared by powder metallurgy, in particular metal injection moulding and additive manufacturing. Due to the high chemical activity, number of titanium oxides, calcium and complex Ca–Ti–oxides can be expected on the component/medical implant surface, depending on powder and component manufacturing and post-treatment, but are very difficult to analyse due to the lack of the experimental data and analysis methodology. Therefore, a methodology for the analysis of the surface chemistry of the Ti-powder by XPS utilising internal standard reference was developed. The obtained methodology was used for the surface analysis of titanium powder and identification of its surface oxide composition. The results show that the powder surface is covered by TiO₂ layer in the form of rutile with a thickness of 4.4?nm. Carbon and nitrogen impurities were also found present on the powder surface.