The highly efficient removal of HCN over Cu8Mn2/CeO2 catalytic material

In this work, porous CeO2 flower-like spheres loaded with bimetal oxides were prepared to achieve effective removal of HCN in the lower temperature region of 30–150 °C.

Thermophysical properties of polymer composites based on secondary polypropylene filled with chalk

One of the most common ways to create polymer composites based on polypropylene is to fill it with chalk, which allows you to improve the appearance of the resulting plastic products and their performance properties. The thermoplasticity of the resulting polymer composites determines the possibility of involving retired polymer materials in re-processing, which requires the study of the laws of the influence of heating on the thermophysical properties of the polymer phase. In this paper, we study the regularities of changes in the thermophysical parameters of polymer composites based on secondary polypropylene in the process of filling it with a chalk additive. It is shown that processing of primary polypropylene by injection molding leads to a decrease in the thermal stability of the resulting secondary polymer material without changing the melting and crystallization temperatures of the polymer phase, but is accompanied by a decrease in the melting enthalpy (by 9 – 11 %) and the degree of crystallinity of the polymer (by 5.6 – 6.5 %). Filling secondary polypropylene with chalk further reduces the temperature of the beginning of decomposition of the composite, while the temperature corresponding to the maximum rate of thermal-oxidative destruction is shifted by 18 – 25 °С to the lower temperature region. The introduction of a 2 mass.p. chalk additive into polypropylene reduces the melting point by 3.6 °С and increases the crystallization temperature of the polymer phase by 1.3 °С. Filling of secondary polypropylene with a chalk additive in the amount of 5 – 10 mass.p. reduces the degree of crystallinity of the polymer, which can lead to changes in the physical and mechanical properties of plastic products.

Copper salt–assisted polymerization of bispropargyl ether–bismaleimide blend

Bispropargyl ether (BPE) of bisphenol-A was prepared. It was blended with 4,4’-bismaleimido diphenyl methane (BMI, 0.5:0.5 mol). The copper sulphate pentahydrate (CuSO4·5H2O) was blended (1% w/w) separately with pure BPE and BPE-BMI blend and the materials were thermally cured. The structural characterization of the materials was done using a Fourier-transform infrared spectrophotometer. The curing behaviour of the materials was investigated using differential scanning calorimetry. The presence of copper salt in BPE shifted the curing temperature to lower temperature region. The presence of copper salt in BPE-BMI blend also decreased the curing onset temperature by approximately 15°C. The thermal property of the polymers was investigated using thermogravimetry. The incorporation of copper salt in BPE-BMI blend led to polymer with increased thermal stability.

Study of averaged collision strength of non-Maxwellian distribution in plasma

In this paper, kappa distribution of electronic energy is discussed for non-Maxwellian distribution. Taking silicon III 189.2 nm line in solar atmospheric plasma as an example, we discuss the kappa distribution and the Maxwellian distribution when temperature varies from [Formula: see text] K to [Formula: see text] K, and we calculate the averaged collision strengths of the kappa distribution and the Maxwellian distribution. Results indicate that the kappa distribution is close to the Maxwellian distribution with the increase of parameter [Formula: see text], and the difference of the averaged collision strength between the kappa distribution and the Maxwellian distribution is not very large in the higher temperature region from [Formula: see text] K to [Formula: see text] K, while that is large in the lower temperature region from [Formula: see text] K to [Formula: see text] K. This discussion will be significant in study of plasma quantitatively.

Comparative study of in situ polymerized waterborne polyurethane/nano-silica composites and polyethersiloxanediol-modified polyurethane

The waterborne polyurethane/nano-silica composites (WPU/nano-silica, WPUS) and WPU composites modified by polyethersiloxanediol (WPUPES) were prepared, respectively. The properties of WPUS and WPUPES were investigated by various characterizations. The results showed both WPUS and WPUPES had better waterproof property and thermal stability than neat WPU. However, WPUPES has a lower elongation at break due to the higher micro-phase separation. This is ascribed to migration and aggregation of siloxane segments during the film formation. The tensile strength of WPUS was higher than that of neat WPU. This is attributed to the WPUS chain restriction caused by the network and physical cross-link points of nano-silica particles. Moreover, the glass transition temperature of WPUS shifted to higher temperature region while that of WPUPES shifted to lower temperature region.

PREPARATION AND ELECTRICAL PROPERTIES OF BiFeO3/La0.7Sr0.3MnO3 MULTILAYERS

( La 0.7 Sr 0.3 MnO 3 12 nm/ BiFeO 3 12 nm)10 was grown on SrTiO 3 (001) substrate using rf magnetron sputtering. The structure analysis indicated that BiFeO 3/ La 0.7 Sr 0.3 MnO 3 multilayers were highly (001)-oriented. Compared with bottom La 0.7 Sr 0.3 MnO 3 electrode, the top La 0.7 Sr 0.3 MnO 3 electrode displayed a rougher surface. The electric transport characteristics of the sample were investigated mainly at low temperature, and it was found that the sample exhibited resistance–temperature curves similar to those of La 0.7 Sr 0.3 MnO 3 with the exception of an upturn at lower temperature region. Furthermore, a nonlinear I–V curve, which is characteristic of a tunneling conduction mechanism, was observed at 50 K. At higher temperature, the I–V curves were found to be diode-like. When the temperature was further increased to 300 K, the sample showed a space charge limited conduction (SCLC) characteristic.

Study on the Reaction and Thermo-Physical Properties of PC and PBT Blend

Blends of polycarbonate (PC) and poly(butylene terephthalate) (PBT) were investigated. For 40 wt % PBT, it forms a continuous phase, the glass transition temperature (Tg) shifts to the lower temperature region. This direct comparison of XRD patterns of pure PBT and PBT containing 1.1% TPPi studied the impact of the crystallization of PBT and TPPi. We can see that diffraction peaks of XRD diagram of PBT/TPPi were broadened. When PBT content was added to 1.1% TPPi, the FWHM increases from 3.8 to 4.2 when diffraction angle was in the range of 16.9 degrees to 17.1 degrees. Thus, the addition of TPPi resulted in the small spherulite size of PBT phase, thus elaborating the sample transparency phenomenon.

Electrical Conduction in Some Nickelates

This paper reports electrical conductivity (s) and Seebeck coefficient (s) study on rare-earth nickelates RNiO3 where R = Nd, Sm and Eu in the temperature range 400-1200 K. They have orthorhombic unit cell. The majority charge carriers are holes throughout the measurement. Both s and S variations show three regions. In higher temperature region (Above 1000K) dominant conduction mechanism is intrisic band type whereas below this temperature, hopping of holes from Ni3+ to Ni2+ centres takes place. In lower temperature region, the electrical conductions is taken over by acceptor type impurities. The conduction mechanism is explained on the basis of every band model. Break temperatures as well as mobility have also been evaluated.

Synthesis of ZnO Nanostructures by Thermal Evaporation on Graphite

ZnO nanostructures have been synthesized on graphite substrates by thermal evaporation of ZnO powder without a metal catalyst at a temperature of 1300. The colors of the as-synthesized products gradually change from white and brown to gray as the distance from the source material increases. ZnO particles were formed at higher temperature region. ZnO particles gradually changed into ZnO nanowire as the temperature decreased. Finally, ZnO nanowires disappeared completely and only Zn particles were observed at lower temperature region.

The formation of boron, silicon and calcium containing molecular species in a graphite furnace in Ar/O2 mixtures

The composition of the Ar/O2/C gas system in the presence of traces of either B, Si or Ca was calculated under the assumption of thermal equilibrium in the temperature range 500.5500 K. The mole concentration of oxygen was taken to be 1.4 %. Two sets of calculations were carried out. In the first one the presence of solid phase (graphite) was ignored and the calculations were performed for a single-phase (gas) system, at variable ratios C/O (0.5, 0.96, 1 and 2). In the second set of calculations the presence of solid carbon (graphite) was taken into account and the composition of the gas system in equilibrium with solid carbon, at p = 1 atm, was determined. The results presented show that the equilibrium composition, particularly the concentration of different compounds involving the trace elements , is very sensitive to the amounts, and the ratio of the amounts of oxygen and carbon. Increasing the O/C ratio results in increasing partial pressures of molecular and atomic oxygen, which favours the formation of oxides of the trace elements and moves their atomization temperatures to higher values. On the other hand, increasing the C/O ratio (C/O >1) favours atomization, but also carbide formation in the lower-temperature region. It was found that, over a relatively wide temperature interval (1000 < T < 3500 K), the composition of theAr/O2/C/X (X = B, Si, Ca) system, with comparable amounts of oxygen and carbon (C/O = 1), does not significantly depend on the presence of the solid phase. The results of calculations enable a reasonable interpretation of numerous experiments carried out on similar systems.