Temperature rise of LaNi5-based alloys by hydrogen absorption

2021 ◽  
Author(s):  
Nanxu Zhou ◽  
Masakuni Yamaguchi ◽  
Hiroki Miyaoka ◽  
Yoshitsugu Kojima
Keyword(s):  
Temperature Rise ◽  
Atmospheric Pressure ◽  
Hydrogen Absorption ◽  
Metal Hydrides ◽  
Type Alloy ◽  
Critical Temperatures

The temperature rise of AB5-type alloy by hydrogen absorption was limited by their critical temperatures (Tc). We found the relation between H2 desorption temperatures of metal hydrides at atmospheric pressure...

Properties and Environmental Considerations Related to AFBC Solid Residues

1986 ◽  
Vol 86 ◽  
Author(s):  
E. E. Berry ◽  
E. J. Anthony
Keyword(s):  
Trace Elements ◽  
Fluidized Bed ◽  
Temperature Rise ◽  
Atmospheric Pressure ◽  
Alkaline Ph ◽  
Fluidized Bed Combustion ◽  
Dissolved Solids ◽  
Factors Influencing ◽  
Coal Ashes ◽  
Environmental Considerations

ABSTRACTAtmospheric-pressure fluidized bed combustion (AFBC) produces solid residues that are different from the familiar pulverized coal ashes. When limestone beds are used to adsorb SOx, high-Ca residues, comprised largely of CaO and SO4, are produced. Leachates from high-Ca AFBC residues are strongly alkaline (pH >11) and contain high levels of dissolved solids (TDS >3000 mg/L). If water is added during handling, hydration of CaO may cause a temperature rise and hydration of CaSO4 may result in premature hardening of the residues. Trace elements and organic components may leach from disposal sites. This paper presents an overview of the nature of AFBC residues and the factors influencing their disposal.

Preparation and Hydrogen Storage Kinetics of Nanocrystalline and Amorphous Mg2Ni-Type Alloys

2013 ◽  
Vol 275-277 ◽  
pp. 1929-1933
Author(s):  
Yang Huan Zhang ◽  
Chen Zhao ◽  
Haitao Wang ◽  
Tai Yang ◽  
Hong Wei Shang ◽  
...  
Keyword(s):  
Hydrogen Storage ◽  
Hydrogen Absorption ◽  
Melt Spinning ◽  
Hydrogen Desorption ◽  
Amorphous Structure ◽  
Absorption Capacity ◽  
Type Alloy ◽  
Cu Alloy ◽  
Nanocrystalline And Amorphous ◽  
Kinetics Of

In order to obtain a nanocrystalline and amorphous structure in the Mg2Ni-type alloy, the melt spinning technology has been used to prepare the Mg20Ni8M2 (M = Co, Cu) hydrogen storage alloys. The microstructures of the alloys were characterized by XRD, SEM and HRTEM. The effects of the melt spinning on the gaseous and electrochemical hydrogen storage kinetics of the alloys were investigated. The results indicate that the as-spun (M = Co) alloys display a nanocrystalline and amorphous structure as spinning rate grows to 20 m/s, while the as-spun (M = Cu) alloys hold an entire nanocrystalline structure even if a limited spinning rate is applied, suggesting that the substitution of Co for Ni facilitates the glass formation in the Mg2Ni-type alloy. The melt spinning remarkably ameliorates the gaseous hydriding and dehydriding kinetics of the alloys. As the spinning rate is raised from 0 (As-cast was defined as the spinning rate of 0 m/s) to 30 m/s, the hydrogen absorption saturation ratio ( ), a ratio of the hydrogen absorption capacity in 5 min to the saturated hydrogen absorption capacity, are enhanced from 80.43% to 94.38% for the (M = Co) alloy and from 56.72% to 92.74% for the (M = Cu) alloy. The hydrogen desorption ratio ( ), a ratio of the hydrogen desorption capacity in 20 min to the saturated hydrogen absorption capacity of the alloy, are increased from 24.52% to 51.67% for the (M = Co) alloy and from14.89% to 40.37% for the (M = Cu) alloy. Furthermore, the high rate discharge ability (HRD) and the hydrogen diffusion coefficient (D) of the alloys notably mount up with the growing of the spinning rate.

scholarly journals Combined Light and Electron Scattering for Exploring Proximity Effects on Hydrogen Absorption in Vanadium

Energies ◽  
2021 ◽  
Vol 14 (24) ◽  
pp. 8251
Author(s):  
Wen Huang ◽  
Xin Xiao ◽  
Parker Steichen ◽  
Sotirios A. Droulias ◽  
Martin Brischetto ◽  
...  
Keyword(s):  
Thermodynamic Properties ◽  
Electron Scattering ◽  
Hydrogen Absorption ◽  
Light Transmission ◽  
Finite Size ◽  
Proximity Effects ◽  
Finite Size Scaling ◽  
Critical Temperatures ◽  
Size Scaling ◽  
Superlattice Structure

We investigate proximity effects on hydrogen absorption in ultra-thin vanadium layers through combing light transmission and electron scattering. We compare the thermodynamic properties of the vanadium layers, which are based on the superlattice structure of Cr/V (001) and Fe/V (001). We find an influence of the proximity effects on the finite-size scaling of the critical temperatures, which can be explained by a variation of dead layers in the vanadium. In addition to this, the proximity effects on hydrogen absorption are also verified from the changes of excess resistivity.

Scuffing Failure of Steel Discs: Conditions for the Failure of Elastohydrodynamic Lubrication

1990 ◽  
Vol 204 (2) ◽  
pp. 91-97 ◽  
Author(s):  
A Dyson ◽  
H P Evans ◽  
G Karami ◽  
M C Paliwal ◽  
R W Snidle
Keyword(s):  
Atmospheric Pressure ◽  
Elastohydrodynamic Lubrication ◽  
Bulk Temperature ◽  
Critical Temperatures ◽  
Lubricating Oils ◽  
Scuffing Failure

Scuffing tests run on circumferentially finished discs were analysed to determine the conditions for the failure of elastohydrodynamic lubrication according to Dyson's theory. The critical lubricant temperatures and viscosities derived from this analysis were compared with the temperatures and viscosities at atmospheric pressure and at the bulk temperature of the discs, as recorded by thermocouples embedded below the surfaces. Tests and corresponding calculations were made for three different lubricating oils and for two steels. The results of the comparison between measured and calculated critical temperatures and viscosities support the concept of scuffing failure as being related to the physical failure of elastohydrodynamic lubrication, even though the lubricants differed significantly in their scuffing behaviour.

Y1Ba2Cu3O7‐x Films from Nitrate Solution using Rf Plasma Deposition

1989 ◽  
Vol 169 ◽  
Author(s):  
A. Shah ◽  
T. Haugan ◽  
S. Witanachchi ◽  
S. Patel ◽  
D. T. Shaw
Keyword(s):  
Atmospheric Pressure ◽  
Plasma Deposition ◽  
Substrate Surface ◽  
Nitrate Solution ◽  
Rf Plasma ◽  
X Ray Diffraction ◽  
Critical Temperatures ◽  
X Ray ◽  
Inductively Coupled ◽  
Current Densities

AbstractA nitrate solution of Y, Ba and Cu was atomized and introduced into an inductively coupled argon ‐ oxygen plasma operated at 4.4 kW and 13.56 MHz under atmospheric pressure. As‐deposited superconducting films were grown on (100) YSZ substrates heated to 650°C. Critical temperatures of 85 K and critical current densities of 7.0 x 104 amp/cm2 at 77 K have been achieved. X‐ray diffraction shows the films to be oriented with the c‐axis perpendicular to the substrate surface. The effects of process parameters, solution composition, and aerosol concentration on the superconducting properties and microstructures will be discussed.

Film Condensation of Steam on Horizontal Finned Tubes: Effect of Fin Spacing

1986 ◽  
Vol 108 (4) ◽  
pp. 960-966 ◽  
Author(s):  
A. S. Wanniarachchi ◽  
P. J. Marto ◽  
J. W. Rose
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Transfer Coefficient ◽  
Temperature Rise ◽  
Atmospheric Pressure ◽  
Smooth Tube ◽  
Film Condensation ◽  
Coolant Temperature ◽  
Finned Tubes ◽  
Fin Spacing

The film condensation heat transfer performance of six externally finned copper tubes has been evaluated. All tubes had rectangular-shaped fins with a height and thickness of 1 mm. The spacing between fins was 0.5, 1.0, 1.5, 2.0, 4.0, and 9.0 mm. Data were also obtained for a smooth tube whose outside diameter of 19.0 mm was equal to the diameter at the base of the fins for all of the finned tubes. Tests were performed both at atmospheric pressure and under vacuum (∼ 11.3 kPa). Steam flowed vertically downward with a velocity of approximately 1 and 2 m/s at atmospheric pressure and under vacuum, respectively. The smooth tube was fitted with wall thermocouples for the evaluation of the water-side heat transfer coefficient. This was used, subsequently, to determine the steam-side heat transfer coefficient for the finned tubes for which only overall measurements were made. Strenuous efforts were made to obtain high-accuracy data; in particular, the coolant temperature rise was determined by both quartz-crystal thermometers and a 10-junction thermopile. The two temperature-rise measurements always agreed to within ± 0.03 K. Care was taken to avoid errors due to the presence of noncondensing gases and to ensure that filmwise condensation conditions prevailed over the entire tube throughout all tests. The steam-side heat transfer coefficient for the smooth tube agreed closely with values found by other recent workers. Maximum steam-side enhancement was found for the tube with a fin spacing of 1.5 mm. At this fin spacing, the heat transfer enhancement ratios were around 3.6 and 5.2 for low-pressure and atmospheric pressure runs, respectively.

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