INFLUENCE OF BLOWING PARAMETERS AND SLAG REGIME ON SILICON AND SULFUR CONTENT IN BLAST-FURNACE CAST IRON

At two blast furnaces (BF) with a volume of 1386 and 1500 m³, the influence of the parameters of blast and slag modes on the content of silicon and sulfur in cast iron was investigated. The blast mode was evaluated by the consumption of pulverized coal fuel (PCF) and oxygen, the slag mode was evaluated by its basicity CaO / SiO₂. It was found that the injection of pulverized coal into the hearth of 1500 m³ BF in the range of flow rates from 108 to 120 g/m³·s, and in the hearth of 1386 m³ BF in the range from 90 to 110 g/m³·s was accompanied by a decrease in the silicon content in cast iron. The deterioration of the transition of silicon into cast iron with an increase in the consumption of pulverized coal is explained by the complex effect of factors that retard the reduction of its oxides. Extreme relationships were also established between the intensity of melting in terms of oxygen consumption and the silicon content in the cast iron of the furnaces under study. The extreme dependences of the studied variables are due to the dual effect of the melting intensity on the reduction of silicon oxides: a reduction in the time of contact of the metal with furnace gases reduces the possibility of transition of silicon into metal, and an increase in the volume of the silicon reduction zone improves these possibilities. When operating a 1386 m³ furnace on calcium slag in the range of CaO / SiO₂ basicity change from 0.9 to 1.3 without removing the blast furnace operation periods associated with a change in operating conditions, the absence of dependence of the silicon content in cast iron on the CaO/SiO₂ modulus was found/ In its turn this indicated the complexity of factors influencing the reduction of silicon oxides. In the same range of changes in basicity and different operating modes of the furnace, a noticeable effect of basicity on the sulfur content in cast iron was observed, which indicates the decisive role of basicity in the process of blast-furnace desulfurization.

A Review of the Progress of Thin-Film Transistors and Their Technologies for Flexible Electronics

Flexible electronics enable various technologies to be integrated into daily life and fuel the quests to develop revolutionary applications, such as artificial skins, intelligent textiles, e-skin patches, and on-skin displays. Mechanical characteristics, including the total thickness and the bending radius, are of paramount importance for physically flexible electronics. However, the limitation regarding semiconductor fabrication challenges the mechanical flexibility of thin-film electronics. Thin-Film Transistors (TFTs) are a key component in thin-film electronics that restrict the flexibility of thin-film systems. Here, we provide a brief overview of the trends of the last three decades in the physical flexibility of various semiconducting technologies, including amorphous-silicon, polycrystalline silicon, oxides, carbon nanotubes, and organics. The study demonstrates the trends of the mechanical properties, including the total thickness and the bending radius, and provides a vision for the future of flexible TFTs.

Bio-functionalization of silicon and its applications in mammalian and cancer cell manipulation and proliferation

Currently fabricated bio-matrices lack important characteristics such as nanometer scale, ‘bumpy’ morphology and an interlinked structure. Therefore, cells cultured on such matrices may not truly represent phenotypes of cells grown in the natural environment. This thesis deals with the synthesis of a three dimensional nanofibrous silicon matrix that is interlinked and possesses a ‘bumpy’ structure that mimics the natural extra cellular matrix. This silicon matrix can be tailored to suit applications of cell proliferation and manipulation. Cell-biomaterial studies show that osteoblasts and fibroblasts proliferated by 300% on three dimensional nanofibrous matrix compared to virgin silicon. To induce controlled cell proliferation, the addition of gold to the silicon matrix was perceived. The phase of gold was altered and combined with silicon forming a unique hybrid structure that prevented the growth of cells in areas of increased gold concentration. Increased gold concentration indicated lower adhesion forces and reduced zeta potentials which consequently lead to decreased cell growth. In addition, the interaction of cancer cells with the three dimensional silicon and gold-silicon hybrid nanofibrous network was studied. Results indicate a 96% reduction in cancer cells compared to virgin silicon. The reduction in cells is attributed to- different phases of silicon and silicon oxides in nanoparticle form, the encapsulation of cells by the nanofibers and apoptosis of cells owing to nanoparticles entering cells passively. To control the growth of cells, silicon surface bio-functionalization was performed to study manipulation of mammalian cells such as fibroblasts as well as cervical and breast cancer cells. The manipulative property is attributed to a mixture of phases of silicon and silicon oxides as well as varied crystal orientations of silicon. It is hypothesized that the mixtures of phases on the substrate alter its surface morphology and consequently induce cell manipulation. Therefore, laser irradiated bio functionalized silicon and its nanostructures are a versatile material for biomedical applications. Based on the process of bio functionalization, both proliferation and cell control and manipulation was achieved in this thesis.

Bio-functionalization of silicon and its applications in mammalian and cancer cell manipulation and proliferation

Currently fabricated bio-matrices lack important characteristics such as nanometer scale, ‘bumpy’ morphology and an interlinked structure. Therefore, cells cultured on such matrices may not truly represent phenotypes of cells grown in the natural environment. This thesis deals with the synthesis of a three dimensional nanofibrous silicon matrix that is interlinked and possesses a ‘bumpy’ structure that mimics the natural extra cellular matrix. This silicon matrix can be tailored to suit applications of cell proliferation and manipulation. Cell-biomaterial studies show that osteoblasts and fibroblasts proliferated by 300% on three dimensional nanofibrous matrix compared to virgin silicon. To induce controlled cell proliferation, the addition of gold to the silicon matrix was perceived. The phase of gold was altered and combined with silicon forming a unique hybrid structure that prevented the growth of cells in areas of increased gold concentration. Increased gold concentration indicated lower adhesion forces and reduced zeta potentials which consequently lead to decreased cell growth. In addition, the interaction of cancer cells with the three dimensional silicon and gold-silicon hybrid nanofibrous network was studied. Results indicate a 96% reduction in cancer cells compared to virgin silicon. The reduction in cells is attributed to- different phases of silicon and silicon oxides in nanoparticle form, the encapsulation of cells by the nanofibers and apoptosis of cells owing to nanoparticles entering cells passively. To control the growth of cells, silicon surface bio-functionalization was performed to study manipulation of mammalian cells such as fibroblasts as well as cervical and breast cancer cells. The manipulative property is attributed to a mixture of phases of silicon and silicon oxides as well as varied crystal orientations of silicon. It is hypothesized that the mixtures of phases on the substrate alter its surface morphology and consequently induce cell manipulation. Therefore, laser irradiated bio functionalized silicon and its nanostructures are a versatile material for biomedical applications. Based on the process of bio functionalization, both proliferation and cell control and manipulation was achieved in this thesis.

Influence of Nano-Modification on Structural, Mechanical and Physico-Chemical Characteristics of Bentonite

The paper studies the influence of nanodispersed aluminum and silicon oxides on the structural, physico-chemical and mechanical characteristics of calcium-magnesium bentonite deposits of the Republic of Tatarstan, in order to determine the optimal concentrations of the nanomodifier, and to improve the performance of respective materials. It was found that nanomodification of bentonite increases the strength of samples after firing by more than 1,5 times, the adsorption index by 20–25 %. The optimal concentration of nanoparticles was determined by changing the properties. The methods of Brunauer-Emmett-Teller (BET), x-ray phase analysis and infrared spectroscopy show an increase in the specific surface area, a change in the phase composition of the annealed samples, the intensity and position of the characteristic absorption bands, as well as the chemical bond silicon-oxygen in bentonite, modified by nanoparticles of aluminum and silicon oxides of similar nature.

Separation of titanium and silicon oxides during plasma-arc melting of quartz-leucoxene concentrate

The aim of the work was investigation of separation of titanium’s and silicon’s oxides during plasma-arc melting of quartz-leucoxene concentrate from Yarega deposit. The melting was proceeded in laboratory plasma-arc furnace in graphite crucible at 16 – 40 kW of arc power. The microstructure and R-x phase analysis of solidified melt were investigated after arc melting. The melt separated on two layers. The upper layer consisted mainly of SiO2 in the form of glass, the lower layer — mainly of cemented titanium oxide particles ≈ 100 μm in dimension. TiO2, Ti8O15, Ti6O11, Fe3TiO3O10, Ti3O5 were observed. These particles formed during melting and moved throw liquid glass to the bottom of crucible with the speed of V ≈ 10–4 m/s. The separation of TiO2 and SiO2 required energy W ≈ 100 GJ/t of concentrate in laboratory plasma arc furnace. The possibility of industrial employment of the arc melting separation was discussed. The estimated energy requirement was about 5 GJ/t in 20-t arc furnace.

Nanoparticles of cerium, iron, and silicon oxides change the metabolism of phenols and flavonoids in butterhead lettuce and sweet pepper seedlings

The aim of the study was to determine the effects of CeO2, Fe2O3, and SiO2 nanoparticles on the metabolism of phenols and flavonoids and the antioxidant status of butterhead lettuce...

Revealing crystal structures and relative dielectric constants of fluorinated silicon oxides

Low dielectric constant (low-k) fluorinated silica is one of the most important materials used in ultralarge scale integrated circuits (ULSIs); however, it is remains unclear what the minimum k possible...