Structural and superconducting properties of Nb3Sn film for superconducting radio-frequency cavities synthesized via bronze route

Superconducting Nb3Sn films were synthesized via the ex-situ annealing of Nb-coated bronze precursors. The precursors were prepared by sputtering 2 [Formula: see text]m of niobium film onto a bronze surface. The annealing was conducted in a vacuum tubular furnace at a temperature not higher than 700[Formula: see text]C. By changing the annealing time and temperature, a series of Nb3Sn samples with critical temperatures ([Formula: see text] > 16 K were obtained. X-ray diffraction confirmed the existence of the cubic Nb3Sn phase (A15 structure), whereas magnetic moment measurements indicated that critical temperature of the studied samples ranged from 16.2 to 16.5 K. Therefore, this study explores a new technique appropriate for creating copper-based Nb3Sn thin-film-coated superconducting radio-frequency (TFSRF) cavities.

ABOUT SOME FEATURES OF LABORATORY RESEARCHES FOR PROCESS OF PULVERIZED FUEL BURNING

The analysis of scientific publications containing information about the equipment and methods of modeling the process of pulverized fuel combustion is carried out. The basic requirements for ensuring the reliability of research results are formulated. The conclusion is made about the possibility and expediency of using installations of the type "vertical tubular furnace" to find ways to increase the completeness of pulverized coal combustion in the blast furnaces raceway. Emphasis is placed on the importance of ensuring a uniform supply of fuel to the reaction zone, a time-stable ratio of fuel and oxidant, qualitative technical analysis of the source fuel, as well as the residue after its combustion. Based on a comparative analysis of methods for determining the completeness of burnout of pulverized fuel used in such studies, a convenient formula for its calculations is proposed.

An Experimental Analysis of Soybean Straw Combustion on Both CO and NOX Emission Characteristics in a Tubular Furnace

In this study, an experiment is conducted to explore the potential to protect both the environment and resource shortage of soybean straw, for combustion in a tubular furnace. Then, the combustion characteristics, gas emissions, and energy consumption of soybean straw are analyzed at a combustion temperature range of 773–1173 K. The results show that the total emissions of CO and NOX are the largest at a temperature of 873 K. For NOX, the emission time is significantly improved at temperatures of 973–1173 K. At high temperatures, the reaction of NOX with CO and coke reduces the total emission of NOX. The average weight loss rate at combustion temperatures of 973, 1073, and 1173 K increased by 27.38%, 61.47% and 77.97%, respectively, relative to that of 873 K. However, the energy consumption increases with the increase in combustion temperature, resulting in unnecessary waste. To get an optimal characteristic between energy utilization and pollutant discharge, a temperature range of 873–973 K is determined as the appropriate temperature for burning soybean straw.

SOME WAYS OF MODERNIZATION INSTALLATION OF METHANOL CRUDE CATALYTIC SYNTHESIS

With due regard for economy of energy resources and optimization of process technological parameters the possibility of replacement of the tubular furnace for heating of gas raw mix by electro heater is considered

Nanoporous Activated Carbons Derived from Peach Stones

In this work, nanoporous activated carbons from Peach Stone powder was achieved using phosphoric acid as an activating agent and carbonization has been conducted at temperatures ranging from 400oC to 700oC using Nitrogen as inert gas in a tubular furnace, to understand the effect of the adsorption capacity with variation in temperature. Evaluation of microporosity of each of these specimens was performed by Iodine Number technique, of which the results showed a maximum amount of micropores in the carbon at the carbonization temperature of 500oC. The morphology of the carbon samples at two extreme temperatures of 400oC and 700oC was studied using FE-SEM images, which demonstrated large amount of nanoporous in the carbon surfaces at the higher temperature. Raman Spectroscopy outcomes delineate the similar amorphous nature of the carbonaceous specimen at these temperatures with both G band and D band. These results indicate a potential to develop a good adsorbent material applicable for water purification.

Characteristics of Low-Temperature Polyvinyl Chloride Carbonization by Catalytic CuAl Layered Double Hydroxide

A good way to make carbon materials was presented in low-temperature polyvinyl chloride (PVC) carbonization by catalysis. The process of low-temperature PVC carbonization by CuAl-layered double hydroxide (CuAl-LDH) was investigated by thermogravimetric analysis (TGA) and tubular furnace. The results show that CuAl-LDH accounting for 5% of PVC mass enabled acceleration of the dehydrochlorination in PVC as soon as possible and maximized the yield of the PVC carbonized product. The vacuum with 0.08 MPa, 20 °C/min heating rate and 90 min carbonized maintenance time were optimal for PVC carbonization. Moreover, the best morphology and yield of the carbonized product was provided at a carbonization temperature of 300 °C.