THE SYSTEMS Li2SO4–K2SO4–H2O AND Li2SO4–Na2SO4–H2O AT 25 °C.

1958 ◽  
Vol 36 (1) ◽  
pp. 171-175 ◽  
Author(s):  
A. N. Campbell ◽  
E. M. Kartzmark

The 25° isotherm of the system Li2SO4–K2SO4–H2O shows the existence of the double salt, Li2SO4. K2SO4, whereas that of the system Li2SO4–Na2SO4–H2O yields no double salt but extensive solid solution of lithium sulphate in sodium sulphate. On the other hand, a study at 39.5 °C. of the latter system shows that the double salt, Li2SO4. Na2SO4, does form at this temperature, accompanied as before by solid solution of lithium sulphate in sodium sulphate. The transition temperature for the reaction[Formula: see text]is 29.3 °C. A further transition, of unknown nature, occurs between 49° and 57°.

2006 ◽  
Vol 980 ◽  
Author(s):  
Sho Tokui ◽  
Kazuhiro Ishikawa ◽  
Kiyoshi Aoki

AbstractIt has been demonstrated that the as-cast Nb40Ti30Ni30 duplex phase alloy, which consists of the primary (Nb, Ti) solid solution and the fine lamellar type eutectic {TiNi+(Nb, Ti)} phase, shows higher hydrogen permeability ¶ than that of pure Pd without the hydrogen embrittlement at 673K. In this alloy, the eutectic phase contributes to the suppression of the hydrogen embrittlement, while the primary one does mainly to the hydrogen permeation. It is important to note that even if the eutectic microstructure disappears and is replaced by the small spherical (Nb, Ti) phase embedded in the TiNi matrix by rolling and subsequent annealing, its high hydrogen permeability and large resistance to the hydrogen embrittlement are sustained. Furthermore, the present authors have observed that the primary (Nb, Ti) phase is largely elongated along the rolling direction. Consequently, it is expected that rolled and annealed Nb-Ti-Ni alloys show the large anisotropy of the microstructure and the hydrogen permeability. In the present work, the microstructure and hydrogen permeability ¶nof the Nb40Ti30Ni30 alloy after rolling and annealing treatments are examined in order to develop highly hydrogen permeable alloys utilizing the anisotropic microstructure.The primary (Nb, Ti) phase and the very fine eutectic {TiNi+(Nb, Ti)} phase are observed in the as-cast Nb40Ti30Ni30 alloy by scanning electron microscopy (SEM). The X-ray diffractometry (XRD) indicates that this alloy consists of the B2-TiNi intermetallic compounds and the bcc- (Nb, Ti) solid solution. The primary (Nb, Ti) phase is largely elongated along the rolling direction by forging and subsequent rolling at 1173 K. On the other hand, the eutectic microstructure becomes unclear with increasing the rolling reduction. The composite alloys in which the (Nb, Ti) phase is elongated along to the rolling direction are obtained by 69 % rolling reduction. ¶n of this sample is four times higher than that of as-cast one. On the other hand, ¶ for the sample vertical to the rolling direction is reduced to about one third of that of as-cast one. Thus, the hydrogen permeability of the Nb40Ti30Ni30 alloy varies about ten times or more depending on the direction of the primary¡]Nb, Ti¡^ phase. We conclude that it is possible to produce highly hydrogen permeable Nb-Ti-Ni alloys using the anisotropy of the microstructure prepared by hot forging and rolling.


1954 ◽  
Vol 32 (7) ◽  
pp. 696-707 ◽  
Author(s):  
A. N. Campbell ◽  
W. J. G. McCulloch ◽  
E. M. Kartzmark

The binary eutectics Li2SO4•H2O–ice and (NH4)2SO4–ice as well as the ternary eutectics Li2SO4•H2O–Li2SO4•(NH4)2SO4–ice and (NH4)2SO4–Li2SO4•(NH4)2SO4–ice have been determined as to temperature and composition. The complete solubility isotherms at 0.1°, 71.8°, and 95.2 °C. have been investigated. The enthalpies of solution of lithium sulphate monohydrate, of ammonium sulphate, and of double salt have been determined (in water at room temperature), and from these data, as well as from the solubility isotherms, it has been shown that the temperature of the transition of the double salt, Li2SO4•(NH4)2SO4, to its component single salts (in the presence of water) is approached by lowering the temperature, but this transition temperature is still far from reached when the system freezes completely.


Materials ◽  
2020 ◽  
Vol 13 (11) ◽  
pp. 2616 ◽  
Author(s):  
Killang Pratama ◽  
Jenifer Barrirero ◽  
Frank Mücklich ◽  
Christian Motz

Thick films of supersaturated solid solution nanocrystalline Co-Cu (28 at.% Cu) were synthesized through the pulsed electrodeposition technique. Microstructural changes of nanocrystalline Co-Cu were intensively studied at various annealing temperatures. Annealing at 300 °C results in a spinodal decomposition within the individual grains, with no grain coarsening. On the other hand, distinct phase separation of Co-Cu is detected at annealing temperatures beyond 400 °C. Static micro-bending tests show that the nanocrystalline Co-Cu alloy exhibits a very high yield strength and ductile behavior, with no crack formation. Static micro-bending tests also reported that a large plastic deformation is observed, but no microstructure change is detected. On the other hand, observation on the fatigue resistance of nanocrystalline Co-Cu shows that grain coarsening is observed after conducting the cyclic micro-bending test.


2008 ◽  
Vol 368-372 ◽  
pp. 1433-1435 ◽  
Author(s):  
Young Seok Kim ◽  
Young Joon Jung ◽  
Kyu Ho Lee ◽  
Tae Ho Kim ◽  
Bong Ki Ryu

The effect of coordination number on glass properties was investigated by measuring the glass forming region, glass transition temperature, dilatometric softening temperature, density and chemical durability of the glasses. The coordination number of B and Zn in the system 20BaO-xZnO-(80-x) B2O3 glasses (x=0~40mol%) was measured by IR, respectively. No change in the coordination number (CN) of B was revealed, and the coordination of Zn was 4 at ZnO 10mol%, which increased the properties of glasses. On the other hand, the coordination number (CN) of B and Zn changed from CN4 to CN3, CN4 to CN6 over ZnO 20 and 10mol% respectively, which decreased the properties of glasses.


2009 ◽  
Vol 23 (06n07) ◽  
pp. 920-926 ◽  
Author(s):  
LIREN CHENG ◽  
ZHANYI CAO ◽  
RUIZHI WU ◽  
MILIN ZHANG

Microstructural characterization of as-cast and extruded experimental alloys as (A) Mg -6.86 Li -3.02 Al -1.12 Ce -0.7 Ca (B) Mg -8.15 Li -3.07 Al -1.12 Ce -0.72 Ca (C) Mg -10.54 Li -3.54 Al -1.23 Ce -0.94 Ca are researched in this paper. The results show that the as-cast specimens of (A) and (B) are composed of α ( Mg ) phase, β ( Li ) phase, rod-like and bulk Al 2 Ce compound. On the other hand, β phase ( Li ), bulk and rod-like Al 2 Ce compound, Al2 Ca compound at boundaries are observed in the as-cast (C) alloy. The addition of Ce and Ca also shows in the microstructure the presence of Al - Ce - Ca phase, a solid solution of Ca in Al 2 Ce compound. In the extruding alloys, the microstructure is refined and the β phase has the effect of coordination during deformation. The long rod-like and the bulk compounds become short rods and fine clumps distributing evenly in the extruding direction after extruding process. The microstructure of extruded Mg -10.54 Li -3.54 Al -1.23 Ce -0.94 Ca alloy testified the existence of eutectic structure.


Micromachines ◽  
2021 ◽  
Vol 12 (10) ◽  
pp. 1225
Author(s):  
Daniel Koske ◽  
Andrea Ehrmann

Poly(lactic acid) (PLA) is one of the most often used polymers in 3D printing based on the fused deposition modeling (FDM) method. On the other hand, PLA is also a shape memory polymer (SMP) with a relatively low glass transition temperature of ~60 °C, depending on the exact material composition. This enables, on the one hand, so-called 4D printing, i.e., printing flat objects which are deformed afterwards by heating them above the glass transition temperature, shaping them and cooling them down in the desired shape. On the other hand, objects from PLA which have been erroneously deformed, e.g., bumpers during an accident, can recover their original shape to a certain amount, depending on the applied temperature, the number of deformation cycles, and especially on the number of broken connections inside the object. Here, we report on an extension of a previous study, investigating optimized infill designs which avoid breaking in 3-point bending tests and thus allow for multiple repeated destruction and recovery cycles with only a small loss in maximum force at a certain deflection.


2009 ◽  
Vol 7 (2) ◽  
pp. 222-227 ◽  
Author(s):  
Piotr Tabero ◽  
Elzbieta Filipek ◽  
Mateusz Piz

AbstractThe IR spectrum of V4Nb18O55 has been compared with the IR spectra of selected niobates of known structures to show structural relations between these compounds. This comparison shows that V4Nb18O55 has crystal structure related to T-Nb2O5, W16Nb18O94 and Ba2NaNb5O15. On the other hand, reaction between V2O5 and H-Nb2O5 yields a solid solution of V2O5 in VNb9O25. It has been proposed two models of synthesized solid solution with formulas V1+xNb9-xO25 or V1+xNb9O25+5x/2.Independently of Nb2O5 polymorph, used for synthesis, the metastable compound VNbO5 cannot be synthesized in the solid state below 650°C


CORROSION ◽  
1969 ◽  
Vol 25 (3) ◽  
pp. 137-146 ◽  
Author(s):  
E. E. LANGENEGGER ◽  
F. P. A. ROBINSON

Abstract It is demonstrated by means of freely corroding total immersion tests and anodic and cathodic polarization experiments, that small amounts of arsenic in solid solution in α-brass, effectively prevent dezincification even in the most agressive media. On the other hand, the addition of relatively large amounts of arsenic ions to these corrosive solutions has little effect on the rate of dezincification of non-arsenical α-brass. Although a contribution towards a better understanding of the function of arsenic has been made, a clear-cut explanation of the mechanism appears to fall outside the scope of this experimentation.


1999 ◽  
Vol 173 ◽  
pp. 249-254
Author(s):  
A.M. Silva ◽  
R.D. Miró

AbstractWe have developed a model for theH2OandOHevolution in a comet outburst, assuming that together with the gas, a distribution of icy grains is ejected. With an initial mass of icy grains of 108kg released, theH2OandOHproductions are increased up to a factor two, and the growth curves change drastically in the first two days. The model is applied to eruptions detected in theOHradio monitorings and fits well with the slow variations in the flux. On the other hand, several events of short duration appear, consisting of a sudden rise ofOHflux, followed by a sudden decay on the second day. These apparent short bursts are frequently found as precursors of a more durable eruption. We suggest that both of them are part of a unique eruption, and that the sudden decay is due to collisions that de-excite theOHmaser, when it reaches the Cometopause region located at 1.35 × 105kmfrom the nucleus.


Author(s):  
A. V. Crewe

We have become accustomed to differentiating between the scanning microscope and the conventional transmission microscope according to the resolving power which the two instruments offer. The conventional microscope is capable of a point resolution of a few angstroms and line resolutions of periodic objects of about 1Å. On the other hand, the scanning microscope, in its normal form, is not ordinarily capable of a point resolution better than 100Å. Upon examining reasons for the 100Å limitation, it becomes clear that this is based more on tradition than reason, and in particular, it is a condition imposed upon the microscope by adherence to thermal sources of electrons.


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