Decrease in grain size

PbO2–MnO2 electrodes were prepared by electrochemical codeposition methods. The electrodes were characterized by scanning electron microscope, X-ray photoelectron spectroscopy, energy dispersive X-ray spectroscopy, and X-ray diffraction. The content of manganese in the electrodes increased with the increase in manganese ion concentration in the solution, which can reach 48.4%. The codeposition of manganese decreased the grain sizes and formed the porous structure.

10p tudichquannguyet 29-11-2021 8 2   Download

In this study we report the effect of sintering temperature on the low field magnetoresistance (LFMR) of La0,7Ca0,3MnO3 manganite synthesized through sol-gel technique. The La0,7Ca0,3MnO3 has been sintered at 600˚C, 700˚C, 800˚C, 900˚C and 1200˚C. The crystallite as well as particle size also show strong dependence on the sintering temperature. While the ferromagnetic – paramagnetic (FM-PM) transition temperature remains almost constant, the metal – insulation transition temperature drop gradual and the low field magnetoresistance (LFMR) increase with a decrease in grain size.

11p nguyenxuankha_bevandan 14-08-2020 15 3   Download

The study of microstructure shows no obvious change of grain size and shape. The magnetic properties of the as-prepared samples show the linear magnetic field dependence of magnetization, suggesting the antiferromagnetic feature of polycrystalline ceramics. The field dependence of magnetization measured after two-years synthesis and after applying an electric field reveal a decrease of maximum magnetization but the hysteresis loops retain the antiferromagnetic behavior.

10p nguyenxuankha_bevandan 14-08-2020 18 2   Download

In this paper, the effects of the welding current in the WAAM process on the shape and the microstructure evolution of thin-walled low-carbon steel components were studied. For this purpose, the thin-walled low-carbon steel samples were built layer-by-layer on the substrates by using an industrial gas metal arc welding robot with different levels of the welding current. The shape, microstructures, and mechanical properties of the thin-walled samples were then analyzed.

12p nguyenxuankha_bevandan 14-08-2020 17 1   Download

Particle size is important parameter affecting the composition, quality and final applications of the producer gas. Fine grained or fluffy feed stock may cause flow problems in the gasifier as well as an inadmissible pressure drop over the reduction zone and a high proportion of dust in the gas. To avoid such problems briquetted material considered for gasification. The developed gasifier was tested with different sizes of briquettes of 15, 30 and 45 mm width and 90 mm diameter. The volatile matter, fixed carbon and ash content of briquette were found as 71.87%, 17.07% and 4.

4p nguaconbaynhay6 23-06-2020 7 0   Download

A study was conducted to see the thousand grain weight variation in Green gram stored in different types of bags. Green gram (Vigna radiate) grains were procured from local market, cleaned and graded by two screen cleaner-cum-grader. Storage study was conducted by storing large sized green gram grains in 4 types of bags (jute, plastic, polythene, hermetic) without and with treatment (aluminium phosphide tablets) at 3 different initial moisture contents (12.34, 14.07, 16.04 % w.b.). Total 21 such bags having different treatment combinations were kept in laboratory for 33 weeks.

7p chauchaungayxua3 07-02-2020 11 1   Download

The study was conducted to investigate some physical properties of soybean at various moisture levels. The dependence of physical properties of soybean on moisture content was determined. In the moisture range from 9.98- 27.10% (wb).The soaked soybean size increased linearly in length (6.34 - 8.95 mm), width (5.42 -6.50 mm), and thickness (4.23 - 5.35 mm) according to final moisture content. In this study, length, width and thickness models based on moisture content are defined as linear models and the regression coefficients (R2 ) related to these models are found between 0.84, 0.72 and 0.

13p quenchua2 15-12-2019 12 0   Download

This paper investigated the Sr doping effect on the microstructure, chemical stability, and conductivity of Ba1 xSrxCe0.65Zr0.25Nd0.1O3 d (0 6 x 6 0.2) electrolyte prepared by sol-gel method. The lattice constants and unit cell volumes were found to decrease as Sr atomic percentage increased in accordance with the Vegard law, confirming the formation of solid solution. Incor- poration of Sr into the composition resulted in smaller grains besides suppressing the formation of secondary phases of SrCeO3. Among the synthesized samples BaCe0.65Zr0.25Nd0.

13p kequaidan1 16-11-2019 17 2   Download

Microstructural analysis indicated that there was no noticeable change in the microstructure of the oxide corresponding to water chemistry changes within the test duration of 100 days (pretransition stage) and no significant difference in the overall thickness of the oxide layer. Equiaxed grains with nano-size pores along the grain boundaries and microcracks were dominant near the water/oxide interface, regardless of water chemistry conditions. As the metal/oxide interface was approached, the number of pores tended to decrease.

9p minhxaminhyeu3 25-06-2019 8 1   Download

The average bubble size increases and the bubble density decreases with an increasing irradiation temperature from 200
C to 350
C. Both the average size and density of the bubbles increase with an increasing irradiation dose from 2 dpa to 8 dpa. Bubbles with smaller size and lower density were observed in the SMATed samples but not in the un-SMATed samples irradiated in the same conditions, which indicate that GBs play an important role during irradiation, and sink strength increases as grain size decreases.

8p minhxaminhyeu3 25-06-2019 15 0   Download