Papers by Keyword: Sodium Nitrate

Abstract: Nanocomposites of tellurium and sodium nitrate were synthesized via a simple thermal dissolution of polycrystalline tellurium powder in nitric acid, followed by tellurium reduction in the presence of sodium dithionite solution. Thin solid films based on these composites have been fabricated and characterized. The morphology, composition and structure of the films were investigated by SEM, EDS, and XRD methods and the possible chemical reactions for the synthesis of relevant nanocomposites were formulated. It has been established that composites consist of nanowires with a diameter of ~100 nm and lengths up to 1,0 micrometers and nanoparticles of 100 ÷ 300 nanometers comprising about 35 at% Te and 7.0 at% of sodium nitrate. It is expected that nanocomposites synthesized via this method can be of interest in producing functional thin films, having both electronic and ionic conductivity.

Abstract: Many advanced machining processes have higher initial investment, maintenance and tooling costs. In these circumstances micro electrochemical machining [µECM] processes meet the requirements with better efficiency and economy. The micro electrochemical machining process parameter such as electrolyte concentration, machine voltage, and pulse on time and duty factor are optimized with considerations of the multiple performance characteristics such as material removal rate (MRR) and overcut. Increase in electrolyte concentration considerably improves MRR but yields a poorer over cut. Increased machine voltage serves to increase both MRR and over cut significantly. Increased pulse on time and duty factor did not have notable impact on MRR and overcut. Less concentration of sodium chloride [NaCl] is sufficient for machining compared with sodium nitrate [NaNO₃]. Higher MRR and better over cut are achieved with sodium chloride and moreover it is more economical than sodium nitrate.

Abstract: Emulsion explosive is one of common industrial explosives, its performance ability is important for producer. So the experiment and theory analysis were made to improve the performance ability of emulsion explosive in this paper. The results show that: performance ability of explosive becomes bigger when oxygen balance of explosive is zero or slightly negative; Water content also has a significant impact on stability, density and explosive performance of emulsion explosive; performance ability of emulsion explosive is generally rises with density increasing. The key approaches of improving the performance ability are that improving the explosion heat and hematocrit and selecting appropriate moisture content and density, and advanced process technology also should be put to use.

Abstract: The existence of high calcium contents in fly ash will contribute to the rapid stiffening and low workability of geopolymer paste. This study reports the feasibility of sodium nitrate and citric acid as the alternative admixtures for geopolymer binder. The effects of sodium nitrate and citric acid were independently evaluated at 0.5%, 1.5% and 2.5% of fly ash weight in geopolymer mixture. The effect of these admixtures on fresh geopolymer characteristic was evaluated through series of setting time and flow table workability tests, while degree of hydration, compressive strength and porosity tests were conducted to provide fundamental information on the hardened properties of geopolymer paste. Based on the result of degree of reaction, the inclusion of sodium nitrate in fly ash based geopolymer will increase the level of degree of hydration. Nevertheless, this result is in contrast with citric acid inclusion where degree of hydration decreased along with the increasing dosage of citric acid in the mixture. Strength development of geopolymer paste, particularly during the early age, appears to be affected by various geopolymerization rate presented by these admixtures.

Abstract: Single-crystal Na_0.5Bi_0.5TiO₃ nanoflakes have been successfully synthesized at 160°C with 8M NaOH by a hydrothermal method assisted by sodium nitrate. The as-prepared samples were characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM). The presence of sodium nitrate was found to play an important role in the growth of single-crystal Na_0.5Bi_0.5TiO₃ nanoflakes.

Abstract: The technology on the leaching process of sodium nitrate from nitratine was developed in this work. The effects of leaching duration, solid-to-liquid ratio on the leaching were studied. The results show that the utilizable sodium nitrate leaching ratio from the nitratine reach 90.2%, for leaching duration of 15 minute and at the solid-to-liquid ratio of 1.0 g.g^-1. A new scheme of step-by-step spray is advanced, according to the result of leaching repeatedly, which increased the concentration of lixiviation up to 29.58%( 400g.L^-1) at 25°C. The results reported will be useful for leaching process design and control.

Abstract: Thermal energy storage is an essential advantage of solar thermal power plants. The present paper focuses on latent heat storage using a phase change material (PCM). The paper lists literature and gives the current status of PCM work in the temperature range 200 to 350 °C. The system KNO3-NaNO3 is discussed in detail in terms of their thermo-physical properties in the liquid and solid phase. A comparison of literature data and own measurements for the density, heat capacity, thermal diffusivity and thermal conductivity is presented. Measurement results with the following methods are discussed: helium pycnometer, differential scanning calorimeter (DSC) and laser flash. Missing data of the thermal diffusivity and thermal conductivity are partly supplemented. Consistent thermo-physical properties in the liquid phase are presented.