Influence Of Elemental Composition Research Articles

Influence of elemental composition in environmental impacts of steel

The environmental behavior of four steels was analyzed. In the operation phase of concentrating solar power plants, steels withstand high temperature because of its contact with molten salts. Hence, choosing the steel type for the molten salt tanks remains a great challenge. In the cold tank, carbon steel is usually used although an approach with low chromium content steel is being studied for these applications. Likewise, in high temperature applications, such as hot store tank, austenitic stainless steel is the most frequent choice. However, ferritic steel is being considered as a promising material in these applications. As many researchers studied the steel technical properties without considering their environmental damages, this work aimed to introduce the environmental aspects into the material choice by using the life cycle assessment technique. On one hand, the results showed the environmental adequacy of carbon steel against low chromium content steel. On the other hand, the results obtained in those steels suitable in high temperature application revealed significant environmental benefits from the ferritic steel instead of the austenitic steel.

Combustion synthesis and luminescence properties of Eu-doped Ca–α-SiAlON

Investigated were the combustion synthesis of Eu-doped Ca–α-SiAlONs and their luminescence properties. Experimentally established were (a) green compositions ensuring maximal extent of conversion, (b) influence of elemental composition on phase composition and microstructure of synthesized Ca–α-SiAlONs, and (c) influence of elemental composition on the excitation and emission spectra of Ca–α-SiAlON luminophors.

Elemental composition effects on self-absorption for photons below 100 keV in gamma-ray spectrometry

The influence of elemental composition in the self-absorption phenomenon is observed. The effective atomic number (Zeff) is used to explain this influence for energies below 100keV. Monte Carlo simulations based on MCNPX and GESPECOR are used to demonstrate the separate impact of Zeff and density ρ on the self-absorption for a given extended sample. Results obtained by simulation are in good agreement with those obtained by the transmission method.

Influence of elemental composition on crystal structure and hydrogen storage performance for Mg-containing alloys

The influence of elemental composition on the crystal structure, hydrogen storage and electrochemical properties for Mg-containing alloys was investigated. As La/Mg ratio decreased, the slight change of Ni content was detected. XRD results indicated that these alloys were composed of LaNi5 and Mg-containing phases. The lattice parameters of Mg-containing phases decreased. Meanwhile, the mass fraction of Mg-containing phases varied with the change of La/Mg and Ni. The hydrogen storage capacity reached ∼1.6 wt.% for La/Mg ≧ 3:1 and decreased to ∼0.71 wt.% for La/Mg=1. Two hydrogen absorption processes were observed because of the existence of the multiphases for La/Mg ≧ 3:1. With decreasing La/Mg ratio, the equilibrium pressure rose due to the shrinkage of the lattice parameter. Meanwhile, one hydrogen absorption process was obviously present. The discharge capacity of these as-cast alloys was higher, but the cyclic stability was poor for La/Mg ≧ 3:1 due to the partial amorphisation. It was better for La/Mg≤2 although the discharge capacity was lower. The polarization resistance increased, contrarily the exchange current density decreased with decreasing Mg content.

Impacts of variations in elemental nutrient concentration of Chardonnay musts on Saccharomyces cerevisiae fermentation kinetics and wine composition

Chardonnay, being the predominant white wine-grape cultivar in the Australian wine sector, is subject to widely varying winemaking processes with the aim of producing a variety of wine styles. Therefore, juice composition might not always be ideal for optimal fermentation outcomes. Our aim was to better understand the composition of Chardonnay juice and how compositional parameters impact on fermentation outcomes. This was achieved through a survey of 96 commercially prepared Chardonnay juices during the 2009 vintage. Common juice variables were estimated using near infrared spectroscopy, and elemental composition was determined using radial view inductively coupled plasma optical emission spectrometry. The influence of elemental composition on fermentation outcomes was assessed by fermentation of a defined medium formulated to reflect the composition and range of concentrations as determined by the juice survey. Yeast (Saccharomyces cerevisiae) strain effects were also assessed. Key parameters influencing fermentation outcomes were verified by laboratory scale fermentation of Chardonnay juice. This exploration of Chardonnay juice identified interactions between juice pH and potassium concentration as key factors impacting on fermentation performance and wine quality. Outcomes differed depending on yeast strain.

A combinatorial study on the influence of elemental composition and heat treatment on the phase composition, microstructure and mechanical properties of Ni–W alloy thin films

Ni–W alloys are promising materials for applications where mechanical stability at relatively high temperature is required. Several Ni–W thin film gradients were synthesized by magnetron sputtering spanning the entire binary composition range. Microstructure and phase composition were characterized by means of X-ray diffraction and transmission electron microscopy, while the mechanical properties were assessed using nanoindentation. As-deposited films exhibit non-equilibrium phases such as amorphous phases in the center of the phase diagram and β-tungsten in the tungsten-rich regime. After annealing, a new X-phase is observed in the center of the phase diagram and non-equilibrium phase compositions are observed for most compositions, such as the presence of α-tungsten at a composition of 75% Ni. Microstructure and composition were successfully correlated to the mechanical properties.

The influence of elemental composition and surface topography on adhesion, proliferation and differentiation of osteoblasts

The influence of elemental composition and surface topography of substrates on the adhesion, proliferation and early differentiation stages of mouse osteoblasts, line MC3T3-E1, cultured on the surface of titanium and multicomponent bioactive nanostructured films (MuBiNaFs) Ti-Ca-(P)-C-O-N and Ti-Ca-Si-C-O-N has been studied. Osteoblasts spread both on the surface of uncoated titanium samples and on the samples coated with the films and had more elongated and irregular shape than the cells cultured on control glass substrate. Immunofluorescence study has shown that osteoblasts formed straight actin bundles associated with focal contacts. Osteoblasts on titanium films formed fewer focal contacts than the cells cultured on Ti-Ca-(P)-C-O-N films. The sandblast treatment did not affect the distribution of the focal contacts and actin structures within the cells. Osteoblasts actively divided on the surface of Ti-Ca-(P)-C-O-N and Ti-Ca-Si-C-O-N films and alteration of surface topography did not affect their growth rate. The quantitative colorimetrical test on alkaline phosphatase activity has shown that modification of surface topography does not affect the level of osteoblastic differentiation. Thus, the elemental composition plays an important role in the interaction of osteoblasts with the surface of films, while the modification of the surface topography in the range of Sq from 0.4 to 1 μm does not influence adhesion, proliferation, and differentiation of osteoblasts.

Influence of Elemental Composition on Fluorescence of Diagenetic Siderite: ABSTRACT

Influence of Elemental Composition on Fluorescence of Diagenetic Siderite: ABSTRACT

Influence of elemental composition on carbonization pyrolysis of sporopollenin and lignite as models of kerogens

Two organic substances (sporopollenin and lignite) were heat-treated as models of kerogens and the resulting chars have been studied by electron microscopy, differential thermal analysis, thermogravimetry and IR spectroscopy. Sporopollenin (H/C = 1.56, O/C = 0.34) melts with decomposition at 436°C. Molecular orientation (1000 Å in extent) appears at 460°C after the weight loss rate maximum. It coincides with the aromatic CH maximum, the OH and carbonyl-carboxyl minima and comes before the aliphatic CH minimum and before the maximum spin concentration as well. Experimental conditions variations (quantity, pressure, action of oxygen) noticeably modify molecular orientation extension (from 50 Å to more than 2000 Å). During pyrolysis, lignite (H/C = 1.12, O/C = 0.44) does not melt and shows a small molecular orientation extension which unlike sporopollenin is not sensitive to experimental conditions. This behaviour is due to persistent oxygenated functions, some of them bonding the aromatic layer stacks. Sporopollenin preheat-treated in air (reticulation) appears comparable to lignite, which confirms the major part played by oxygen as far as melting and molecular orientation are concerned.