Hydrogen absorption of C14 Laves NiTiZr-NiVNb pseudo-binary alloys

2003 ◽  
Vol 801 ◽  
Author(s):  
Kazuhiro Ishikawa ◽  
Shintaro Noda ◽  
Kiyonori Suzuki ◽  
Kiyoshi Aoki
Keyword(s):  
Binary System ◽  
Hydrogen Absorption ◽  
Binary Alloys ◽  
Hydrogen Desorption ◽  
Absorption Capacity ◽  
The Other ◽  
Hydrogen Capacity ◽  
Desorption Temperature ◽  
Other Hand ◽  
Zr Alloy

ABSTRACTHydrogen absorption and desorption properties of C14 Laves NiTiZr-NiVNb and NiTiZr-NiVZr pseudo-binary alloys were investigated by using the Sieverts' apparatus, XRD and the hydrogen analyzer. The hydrogen capacity and the 50% hydrogen desorption temperature, Td, of the C14 Laves NiTiZr alloy is 1.5 (H/M) and 850 K, respectively. On the other hand, the hydrogen capacity of the C14 NiVNb alloy is 0.2 H/M. In the Ni(TiZr)1−x(VNb)x pseudo-binary system, the hydrogen capacity of the alloys is decreased with increasing x, but the 50% hydrogen desorption temperature is almost constant. The substitution of VNb reduces the hydrogen absorption capacity of the C14 Laves NiTiZr alloy. The hydrogen desorption temperature of Ni(Ti1−xVx)Zr alloy is reduced to 580 K without serious decrease of the hydrogen capacity with increasing x.

scholarly journals FAR-Ultralviolet Spectrophotometry of two do White Dwarfs from Voyager

1989 ◽  
Vol 114 ◽  
pp. 144-148
Author(s):  
E. Poulin ◽  
F. Wesemael ◽  
J.B. Holberg ◽  
G. Fontaine
Keyword(s):  
Binary System ◽  
White Dwarfs ◽  
Temperature Scale ◽  
Classification Scheme ◽  
The Other ◽  
Other Hand ◽  
Effective Temperatures

While the observed number of hot, helium-rich degenerates is noticeably larger than that of their hydrogen-rich counterparts, the calibration of their effective temperatures has been comparatively much less trustworthy. The spectroscopic classification scheme introduced three years ago by Wesemael, Green, and Liebert (1985, hereafter WGL), and the crude temperature domains associated with each class remain, to this date, the only comprehensive effort at defining a temperature scale for DO stars. The current uncertainty in this is perhaps best epitomized by two objects, HD149499B and PG1034+001. The former belongs to a binary system which also contains a KO V primary, 2” away. The temperature determined for the degenerate secondary ranges from 85,000±15,000 K (Wray, Parsons, and Henize 1979) to 55,000±5000 K (Sion, Guinan, and Wesemael 1982, hereafter SGW). PG1034+001, on the other hand, is the prototype of the so-called hot DO spectroscopic class; WGL assign an uncertain temperature of 80,000±20,000 K to this object.

Hydriding and Dehydriding Characteristics of As-Spun Nanocrystalline and Amorphous Mg20Ni10-xMnx (x = 0-4) Alloys

2011 ◽  
Vol 347-353 ◽  
pp. 3420-3424
Author(s):  
Yang Huan Zhang ◽  
Xiao Gang Liu ◽  
Le Le Chen ◽  
Hui Ping Ren ◽  
Guo Fang Zhang ◽  
...  
Keyword(s):  
Amorphous Phase ◽  
Hydrogen Absorption ◽  
Melt Spinning ◽  
Hydrogen Desorption ◽  
Absorption Capacity ◽  
Desorption Kinetics ◽  
Nanocrystalline And Amorphous ◽  
Cast Alloys ◽  
Mn Content ◽  
Kinetics Of

The nanocrystalline and amorphous Mg2Ni-type Mg20Ni10-xMnx (x = 0, 1, 2, 3, 4) alloys were synthesized by melt-spinning technique. The structures of the as-cast and spun alloys were characterized by XRD, SEM and HRTEM. The hydrogen absorption and desorption kinetics of the alloys were measured. The results show that the substitution of Mn for Ni, instead of changing the major phase Mg2Ni, leads to the formation of Mg and MnNi phases. No amorphous phase is detected in the as-spun Mn-free alloy, but the as-spun alloys substituted by Mn display the presence of an amorphous phase, suggesting that the substitution of Mn for Ni enhances the glass forming ability of the Mg2Ni-type alloy. The hydrogen absorption capacity of the as-cast alloys first increases and then decreases with the variation of the amount of Mn substitution. The hydrogen desorption capacity of the alloys markedly increases with growing Mn content.

Sound Absorption Behavior of Porous Al Produced by Spacer Method

2006 ◽  
Vol 15-17 ◽  
pp. 422-427
Author(s):  
Tetsumune Kuromura ◽  
Masataka Hakamada ◽  
Y. Chen ◽  
Hiromu Kusuda ◽  
Mamoru Mabuchi
Keyword(s):  
Absorption Coefficient ◽  
Pore Size ◽  
Sound Absorption ◽  
Size Range ◽  
Absorption Capacity ◽  
The Other ◽  
Sound Absorption Coefficient ◽  
Specimen Thickness ◽  
Pore Sizes ◽  
Other Hand

Porous Al specimens with a pore size range from 212-300 to 610-700 μm, a porosity from 85 to 95% and a specimen thickness from 2 to 20 mm were produced by the spacer method, and their sound absorption capacity was investigated. For these specimens, sound absorption coefficient increased with increasing porosity. On the other hand, sound absorption coefficient varied inconsistently with the variation of pore sizes. The latter may be attributed to variation of aperture sizes of each specimen because the porous Al specimens with differerent pore sizes produced by the spacer method should have different aperture sizes. Sound absorption coefficient increased at the frequency below 2000 Hz with increasing specimen thickness.

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 Functional properties of composite flours produced with Ivorian taro (Colocasia esculenta L. Cv Fouê) corms flour and wheat (Triticum aestivum L.) flour

2021 ◽  
Vol 15 (3) ◽  
pp. 164-176
Author(s):  
Anon Attoh Hyacinthe ◽  
Fagbohoun Jean Bedel ◽  
Koffi Amoin Gisèle ◽  
Anno Hermann Fourier Atta ◽  
Kouamé Lucien Patrice
Keyword(s):  
Triticum Aestivum ◽  
Functional Properties ◽  
Water Solubility ◽  
Triticum Aestivum L ◽  
Absorption Capacity ◽  
Colocasia Esculenta ◽  
The Other ◽  
Other Hand ◽  
Composite Flours ◽  
The Stability

The general objective of this work was to assess the functional properties of composite flours obtained from the flour of Ivorian taro corms (Colocasia esculenta, Cv Fouê) with wheat flour (Triticum aestivum L.). The results concerning the functional properties revealed significant differences (p <0.05). Indeed, the water absorption capacity, the water solubility index and the hydrated density increase considerably in the various composite flours. On the other hand, the bulk density, clarity, wettability and porosity have decreased in these flours. In addition, the stability of the foam and the dispersibility have increased over time. On the other hand, the hydrophilic / lipophilic ratio is greater than 1 with the exception of red oil.

Effect of Electroless Ni-P Plating on Mechanical Properties of Al-4%Ge Alloy

2016 ◽  
Vol 879 ◽  
pp. 897-902
Author(s):  
Teruto Kanadani ◽  
Norihito Nagata ◽  
Makoto Hino ◽  
Koji Murakami ◽  
Keitaro Horikawa ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Fatigue Strength ◽  
Aging Treatment ◽  
Hydrogen Desorption ◽  
Hydrogen Gas ◽  
The Other ◽  
Breaking Elongation ◽  
Other Hand ◽  
Stress Region ◽  
Electroless Ni

In this study, the effect of electroless Ni-P plating on the mechanical properties of Al-4%Ge alloy was investigated. As the results, the following points were clarified. (i) Tensile strength of the specimen subjected to the Ni-P plating after aging treatment or furnace cooling treatment was improved by about 10% in comparison to one of the non-processed specimens. (ii) Breaking elongation of the specimen subjected to the Ni-P plating after aging treatment showed no significant changes in comparison to one of the non-processed specimens. On the other hand, breaking elongation of the specimen subjected to Ni-P plating after a furnace cooling treatment was reduced to 70% in comparison to one of the non-processed specimens. (iii) Fatigue strength of the specimen subjected to the Ni-P plating after a furnace cooling treatment was overall reduced rather than one of non-processed specimens. (iv) Fatigue strength of the specimen subjected to the Ni-P plating after aging treatment was overall reduced, except for the low-stress region, rather than one of the non-processed specimens. (v) In the specimen subjected to Ni-P plating after a furnace cooling treatment or aging treatment, clear hydrogen desorption was recognized. On the other hand, there was only hydrogen desorption from a few of the non-processed specimens. Especially, it is considered that the poor fatigue strength and ductility of the plating materials are mainly due to the interaction between the surface precipitates and hydrogen gas.

Effect of Zr Addition on Recrystallization Behavior of Extruded Al-Mg-Si Alloys Containing Mn

2014 ◽  
Vol 794-796 ◽  
pp. 1169-1174
Author(s):  
Kentaro Ihara ◽  
Takahiro Shikama
Keyword(s):  
Formation Process ◽  
Homogenization Temperature ◽  
Hot Compression ◽  
The Other ◽  
Recrystallization Behavior ◽  
Zener Drag ◽  
Zr Addition ◽  
Other Hand ◽  
Grain Structures ◽  
Zr Alloy

Effects of Zr addition on recrystallized structure and texture in extruded Al-Mg-Si alloy containing Mn have been investigated. Materials were homogenized at temperatures in the range 550 °C to 590 °C and extruded at 500 °C at the speed of 10m/min. In extruded Al-Mg-Mn-Si-Zr alloy, the fraction of Cube oriented grains reached 40% as homogenization temperature raised to 590 °C. On the other hand, the fraction of Cube oriented grains in extruded Al-Mg-Mn-Si alloy was limited to 20-30 %. In addition, to clear the formation process of recrystallized grains in these alloys, observation of hot-compression deformed and recrystallized grain structures were carried out. It was suggested that moderate Zener drag promoted the preferential recrystallization of cube oriented grains

scholarly journals Spatial aspects of the Sectoral Operational Programme − Agriculture and Rural Development − implementation in the Slovak Republic

2008 ◽  
Vol 53 (No. 5) ◽  
pp. 217-223
Author(s):  
S. Buchta ◽  
Z. Rentková
Keyword(s):  
Spatial Distribution ◽  
Rural Development ◽  
Slovak Republic ◽  
Absorption Capacity ◽  
The Other ◽  
Other Hand ◽  
High Absorption

The contribution deals with the spatial distribution of approved projects under the Sectoral Operational Programme &minus; Agriculture and Rural Development (SOP ARD) in the programme period 2004&minus;2006. The approved projects from agrifood industry were concentrated in the production regions of western and southern Slovakia. It does not indicate only the high absorption capacity of the enterprise subjects, but also really well prepared projects in these regions. In the next programme period, we will have to count with unevenly distributed projects. On the other hand, the low absorption ability in the northern and mainly eastern areas of the SR may result in forming the islands of extreme extensity with negative socio-economical impacts. The SOP ARD (analogous to Sapard) accelerates the process of enterprising selection and significantly supports the increase of competitiveness in economically powerful farms.

scholarly journals Magnetic field in a young circumbinary disk

2018 ◽  
Vol 616 ◽  
pp. A56 ◽  
Author(s):  
F. O. Alves ◽  
J. M. Girart ◽  
M. Padovani ◽  
D. Galli ◽  
G. A. P. Franco ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Binary System ◽  
Thermal Emission ◽  
The Other ◽  
Toroidal Magnetic Field ◽  
Continuum Emission ◽  
Disk Model ◽  
Radiation Fields ◽  
Other Hand ◽  
The Magnetic Field

Context. Polarized continuum emission at millimeter-to-submillimeter wavelengths is usually attributed to thermal emission from dust grains aligned through radiative torques with the magnetic field. However, recent theoretical work has shown that under specific conditions polarization may arise from self-scattering of thermal emission and by radiation fields from a nearby stellar object. Aims. We use multi-frequency polarization observations of a circumbinary disk to investigate how the polarization properties change at distinct frequency bands. Our goal is to discern the main mechanism responsible for the polarization through comparison between our observations and model predictions for each of the proposed mechanisms. Methods. We used the Atacama Large Millimeter/submillimeter Array to perform full polarization observations at 97.5 GHz (Band 3), 233 GHz (Band 6) and 343.5 GHz (Band 7). The ALMA data have a mean spatial resolution of 28 AU. The target is the Class I object BHB07-11, which is the youngest object in the Barnard 59 protocluster. Complementary Karl G. Jansky Very Large Array observations at 34.5 GHz were also performed and revealed a binary system at centimetric continuum emission within the disk. Results. We detect an extended and structured polarization pattern that is remarkably consistent between the three bands. The distribution of polarized intensity resembles a horseshoe shape with polarization angles following this morphology. From the spectral index between Bands 3 and 7, we derived a dust opacity index β ~ 1 consistent with maximum grain sizes larger than expected to produce self-scattering polarization in each band. The polarization morphology and the polarization levels do not match predictions from self-scattering. On the other hand, marginal correspondence is seen between our maps and predictions from a radiation field model assuming the brightest binary component as main radiation source. Previous molecular line data from BHB07-11 indicates disk rotation. We used the DustPol module of the ARTIST radiative transfer tool to produce synthetic polarization maps from a rotating magnetized disk model assuming combined poloidal and toroidal magnetic field components. The magnetic field vectors (i.e., the polarization vectors rotated by 90°) are better represented by a model with poloidal magnetic field strength about three times the toroidal one. Conclusions. The similarity of our polarization patterns among the three bands provides a strong evidence against self-scattering and radiation fields. On the other hand, our data are reasonably well reproduced by a model of disk with toroidal magnetic field components slightly smaller than poloidal ones. The residual is likely to be due to the internal twisting of the magnetic field due to the binary system dynamics, which is not considered in our model.

scholarly journals Entropy of Mixing of Cadmium-based Liquid Alloys

1970 ◽  
Vol 26 ◽  
pp. 40-45
Author(s):  
S. K. Chakrabarti ◽  
B. K. Jha ◽  
I. S. Jha
Keyword(s):  
Thermodynamic Properties ◽  
Binary Alloys ◽  
The Other ◽  
Chemical Model ◽  
Liquid Alloys ◽  
Atomic Composition ◽  
Reactive Metal ◽  
Entropy Of Mixing ◽  
Binary Liquid ◽  
Other Hand

Cadmium is a highly reactive metal. At the time of formation of binary alloys in liquidphase it often forms complexes. In the present work we have considered two such complexforming binary liquid alloys of cadmium e.g. Cd-Na and Cd-Mg. The former alloy showsanomaly in its thermodynamic properties of mixing. On the other hand, the alloyingbehavior of the latter one is symmetric around the equi-atomic composition. We havecomputed their entropy of mixing (SM) for different concentrations of the ingredients byusing the quasi-lattice chemical model. The results explain the observed anomaly as well assymmetry in SM of the present alloys.Keywords: Binary liquid alloys of cadmium; Quasi-lattice chemical model; Entropy of mixingDOI: 10.3126/jncs.v26i0.3629Journal of Nepal Chemical SocietyVol. 26, 2010Page:40-45

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