THE SYSTEM LITHIUM SULPHATE – AMMONIUM SULPHATE – WATER

1954 ◽  
Vol 32 (7) ◽  
pp. 696-707 ◽  
Author(s):  
A. N. Campbell ◽  
W. J. G. McCulloch ◽  
E. M. Kartzmark
Keyword(s):  
Transition Temperature ◽  
Ammonium Sulphate ◽  
Room Temperature ◽  
Double Salt ◽  
Enthalpies Of Solution ◽  
Lithium Sulphate ◽  
Solubility Isotherms ◽  
Ternary Eutectics ◽  
Sulphate Water

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.

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
Keyword(s):  
Solid Solution ◽  
Transition Temperature ◽  
Sodium Sulphate ◽  
Double Salt ◽  
The Other ◽  
Other Hand ◽  
Lithium Sulphate

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°.

RECIPROCAL SALT PAIRS, INVOLVING THE CATIONS Li2, Na2, AND K2, THE ANIONS SO4, AND Cl2, AND WATER, AT 25 °C

1958 ◽  
Vol 36 (11) ◽  
pp. 1511-1517 ◽  
Author(s):  
A. N. Campbell ◽  
E. M. Kartzmark ◽  
E. G. Lovering
Keyword(s):  
Sodium Chloride ◽  
Potassium Chloride ◽  
Mole Fraction ◽  
Lithium Chloride ◽  
Invariant Point ◽  
Double Salt ◽  
Potassium Sulphate ◽  
Lithium Sulphate ◽  
Solid Phases ◽  
Chloride Monohydrate

In the reciprocal salt pair Li2, K2, Cl2, SO4, and water, at 25 °C there are large areas in which potassium sulphate and potassium lithium sulphate (KLiSO4) are separately in equilibrium with solution. Two incongruent invariant points exist. At one of these the composition of the solution is 0.917 mole fraction chloride, 0.437 mole fraction lithium, and 19.4 moles of water per total mole of salt, the equilibrium solid phases being potassium chloride, potassium sulphate, and the double salt. At the second, the composition of the solution is 0.967 mole fraction chloride, 0.870 mole fraction lithium, and 13.8 moles of water per mole of salt, the solid phases being potassium chloride, double salt, and lithium sulphate monohydrate. One congruent invariant point exists, at which the composition of the solution is 1.00 mole fraction chloride, 0.960 mole fraction lithium, and 9.6 moles of water per mole of salt, the solid phases being lithium sulphate monohydrate, lithium chloride monohydrate, and potassium chloride.In the reciprocal salt pair Li2, Na2, Cl2, SO4, and water, at 25 °C there is an incongruent invariant point at which the composition of the solution is 0.873 mole fraction chloride, 0.668 mole fraction lithium, and 15.1 moles water per total mole of salt, the solid phases being sodium chloride, solid solution of sodium and lithium sulphates, and lithium sulphate monohydrate. A congruent invariant point exists, at which the composition of the solution is practically entirely lithium chloride, the solid phases present being lithium chloride monohydrate, lithium sulphate monohydrate, and sodium chloride.

scholarly journals Computational Intelligence Approach for Estimating Superconducting Transition Temperature of Disordered MgB2Superconductors Using Room Temperature Resistivity

2016 ◽  
Vol 2016 ◽  
pp. 1-7 ◽  
Author(s):  
Taoreed O. Owolabi ◽  
Kabiru O. Akande ◽  
Sunday O. Olatunji
Keyword(s):  
Transition Temperature ◽  
Superconducting Transition Temperature ◽  
Room Temperature ◽  
Optimization Technique ◽  
Support Vector ◽  
Measuring Instruments ◽  
Room Temperature Resistivity ◽  
Superconducting Transition ◽  
Experimental Values ◽  
Temperature Resistivity

Doping and fabrication conditions bring about disorder in MgB2superconductor and further influence its room temperature resistivity as well as its superconducting transition temperature (TC). Existence of a model that directly estimatesTCof any doped MgB2superconductor from the room temperature resistivity would have immense significance since room temperature resistivity is easily measured using conventional resistivity measuring instrument and the experimental measurement ofTCwastes valuable resources and is confined to low temperature regime. This work develops a model, superconducting transition temperature estimator (STTE), that directly estimatesTCof disordered MgB2superconductors using room temperature resistivity as input to the model. STTE was developed through training and testing support vector regression (SVR) with ten experimental values of room temperature resistivity and their correspondingTCusing the best performance parameters obtained through test-set cross validation optimization technique. The developed STTE was used to estimateTCof different disordered MgB2superconductors and the obtained results show excellent agreement with the reported experimental data. STTE can therefore be incorporated into resistivity measuring instruments for quick and direct estimation ofTCof disordered MgB2superconductors with high degree of accuracy.

Silk Polymer Coating with Low Dielectric Constant and High Thermal Stability for Ulsi Interlayer Dielectric

1997 ◽  
Vol 476 ◽  
Author(s):  
P. H. Townsend ◽  
S. J. Martin ◽  
J. Godschalx ◽  
D. R. Romer ◽  
D. W. Smith ◽  
...  
Keyword(s):  
Thin Film ◽  
Dielectric Constant ◽  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Integrated Circuits ◽  
Room Temperature ◽  
Polymer Network ◽  
Flow Characteristics ◽  
Interlayer Dielectric

AbstractA novel polymer has been developed for use as a thin film dielectric in the interconnect structure of high density integrated circuits. The coating is applied to the substrate as an oligomeric solution, SiLK*, using conventional spin coating equipment and produces highly uniform films after curing at 400 °C to 450 °C. The oligomeric solution, with a viscosity of ca. 30 cPs, is readily handled on standard thin film coating equipment. Polymerization does not require a catalyst. There is no water evolved during the polymerization. The resulting polymer network is an aromatic hydrocarbon with an isotropie structure and contains no fluorine.The properties of the cured films are designed to permit integration with current ILD processes. In particular, the rate of weight-loss during isothermal exposures at 450 °C is ca. 0.7 wt.%/hour. The dielectric constant of cured SiLK has been measured at 2.65. The refractive index in both the in-plane and out-of-plane directions is 1.63. The flow characteristics of SiLK lead to broad topographic planarization and permit the filling of gaps at least as narrow as 0.1 μm. The glass transition temperature for the fully cured film is greater than 490 °C. The coefficient of thermal expansivity is 66 ppm/°C below the glass transition temperature. The stress in fully cured films on Si wafers is ca. 60 MPa at room temperature. The fracture toughness measured on thin films is 0.62 MPa m ½. Thin coatings absorb less than 0.25 wt.% water when exposed to 80% relative humidity at room temperature.

Influence of Gd Addition on the Structure and Capability of Ni-Mn-In Metamagnetic Shape Memory Alloys

2012 ◽  
Vol 535-537 ◽  
pp. 950-953
Author(s):  
Li Na Bai ◽  
Gui Xing Zheng ◽  
Zhi Jian Duan ◽  
Jian Jun Zhang
Keyword(s):  
Differential Scanning Calorimetry ◽  
Magnetic Properties ◽  
Magnetic Property ◽  
Transition Temperature ◽  
Martensitic Transformation ◽  
Room Temperature ◽  
Vibrating Sample Magnetometry ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray

The influences of Gd concentration on martensitic transformation and magnetic properties of NiMnIn alloys were investigated by differential scanning calorimetry (DSC) , vibrating sample magnetometry (VSM), X-ray diffraction (XRD) and etc. It is Observed through the experiment: the addition of Gd enhances martensite transition temperature;X-ray diffraction analysis of experimental alloys is revealed that to the mixture is martensite and austenite at room temperature; content of Gd is not proportional to the improvement of magnetic property.

The use of a bree simulation to investigate strain accumulation in 316 stainless steel at temperatures between room temperature and 500°c

1989 ◽  
Vol 24 (2) ◽  
pp. 95-102 ◽  
Author(s):  
D J Brookfield ◽  
D N Moreton
Keyword(s):  
Stainless Steel ◽  
Transition Temperature ◽  
Room Temperature ◽  
Elevated Temperatures ◽  
Cyclic Change ◽  
Strain Accumulation ◽  
Temperature Behaviour ◽  
Design Rules ◽  
Axial Tension ◽  
Applied Stresses

This paper details tests undertaken to determine the 1 per cent strain accumulation boundary in stainless steel type 316 strip subjected to constant axial tension and a cyclic change of curvature. Boundaries are obtained for temperatures between 300 and 500°C. These are compared with two design rules, both of which are shown to be conservative. Additionally, the temperature at which the transition from the characteristic room temperature behaviour of continued ratchetting to the ‘shakedown’ observed at elevated temperatures is investigated. Results obtained indicate that this transition temperature is influenced by the magnitude of the applied stresses.

Thermal Diffusivity and Conductivity of La0.7Ca0.3-xSrxMnO3 (x=0 to 0.10)

2012 ◽  
Vol 501 ◽  
pp. 319-323
Author(s):  
Hasan A. Alwi ◽  
Lay S. Ewe ◽  
Zahari Ibrahim ◽  
Noor B. Ibrahim ◽  
Roslan Abd-Shukor
Keyword(s):  
Thermal Conductivity ◽  
Electrical Conductivity ◽  
Grain Size ◽  
Transition Temperature ◽  
Thermal Diffusivity ◽  
Electrical Properties ◽  
Room Temperature ◽  
Electronic Contribution ◽  
Insulator Metal Transition ◽  
Thermal And Electrical Properties

We report the room temperature thermal conductivity κ and thermal diffusivity α of polycrystalline La0.7Ca0.3-xSrxMnO3 for x = 0 to 0.1. The samples were prepared by heating at 1220 and 1320oC. The insulator-metal transition temperature, TIM and thermal diffusivity increased with Sr content. Phonon was the dominant contributor to thermal conductivity and the electronic contribution was less than 1%. Enhancement of electrical conductivity σ and thermal diffusivity for x ≥ 0.08 was observed in both series of samples. The grain size of the samples (28 to 46 µm) does not show any affect on the thermal and electrical properties.

PROPERTIES OF BOVINE Ac-GLOBULIN CONCENTRATES AND METHODS OF PREPARATION

1963 ◽  
Vol 41 (1) ◽  
pp. 2409-2421 ◽  
Author(s):  
Nobuo Aoki ◽  
Charles R. Harmison ◽  
Walter H. Seegers
Keyword(s):  
Human Plasma ◽  
Ammonium Sulphate ◽  
Protein Concentration ◽  
Room Temperature ◽  
Specific Activity ◽  
Barium Carbonate ◽  
Dry Weight ◽  
Physical Chemical ◽  
Bovine Plasma ◽  
Refrigerator Temperature

A procedure is described for retaining bovine plasma Ac-globulin activity as one part of the protein from plasma for every 1000 parts removed. The yields averaged 15%. The procedure involves removal of prothrombin with barium carbonate, isoelectric fractionation, fractionation with ammonium sulphate, chromatography on Amberlite IRC-50, and a second fractionation with ammonium sulphate. The procedure requires 2 days; however, the first day completes up to chromatography and the concentrate at that time is quite useful for many purposes. It is more stable than the product obtained after chromatography and the yields are higher. In absence of salts Ac-globulin is quite insoluble at pH 5.0. The final product usually contained some impurity. With the analytical ultra-centrifuge the S20in 0.1 M potassium chloride solution was found to be 4.2 at a protein concentration of 12.4 mg/ml. The specific activity was 1500 U./mg dry weight. Bovine plasma contains 120 U./ml or about 9 mg/100 ml. Assuming the same specific activity for human plasma the concentration is most likely near 1 mg/100 ml. The best stability conditions found were: 50% glycerol, pH 7.0, and 0.1 M calcium chloride. Under those conditions at room temperature all activity was retained 6 to 7 hours, at refrigerator temperature 24 hours, and at −60 °C for 1 month. In rabbits, antibodies were readily produced. Oxidizing agents destroyed the activity, while reducing agents did not, nor did they tend to stabilize. SH blocking agents destroyed the activity. The loss of activity in the presence of 0.0025 M parachloromercuribenzoate was recovered with 0.04 M cysteine. The molecule deteriorated while attempts were made to obtain physical chemical data; consequently, the molecular weight was calculated from an amino acid analysis and found to be 98,800. The reliability of this value is problematical. Human plasma was analyzed and found to contain 13 U./ml Ac-globulin. After 4 days storage, at room temperature, the prolonged prothrombin time of that plasma was completely restored with 13 units of Ac-globulin, which is equivalent to 8 μg.

The Effect of Thermal History on Porcelain Expansion Behavior

1989 ◽  
Vol 68 (9) ◽  
pp. 1313-1315 ◽  
Author(s):  
C.W. Fairhurst ◽  
D.T. Hashinger ◽  
S.W. Twiggs
Keyword(s):  
Thermal Expansion ◽  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Heating Rate ◽  
Room Temperature ◽  
Heating Rates ◽  
Thermal Expansion Data ◽  
Temperature Range ◽  
Expansion Behavior

Porcelain-fused-to-metal restorations are fired several hundred degrees above the glass-transition temperature and cooled rapidly through the glass-transition temperature range. Thermal expansion data from room temperature to above the glass-transition temperature range are important for the thermal expansion of the porcelain to be matched to the alloy. The effect of heating rate during measurement of thermal expansion was determined for NBS SRM 710 glass and four commercial opaque and body porcelain products. Thermal expansion data were obtained at heating rates of from 3 to 30°C/min after the porcelain was cooled at the same rate. By use of the Moynihan equation (where Tg systematically increases in temperature with an increase in cooling/heating rate), the glass-transition temperatures (Tg) derived from these data were shown to be related to the heating rate.

scholarly journals The principal magnetic susceptibilities of some paramagnetic crystals at low temperatures

1933 ◽  
Vol 140 (842) ◽  
pp. 695-713 ◽  
Keyword(s):  
Ammonium Sulphate ◽  
Low Temperatures ◽  
Room Temperature ◽  
Manganese Carbonate ◽  
Small Range ◽  
Restricted Range ◽  
Nickel Sulphate ◽  
Temperature Range ◽  
Naturally Occurring ◽  
Ferrous Carbonate

Our knowledge of the temperature variation of the principal susceptibilities of paramagnetic crystals is as yet fragmentary. The principal susceptibilities of a number of paramagnetic crystals have been determined by Finke and by Rabi at room temperature but the first measurements on orientated crystals over any range of temperature were those of Foëx. He has published the principal susceptibilities of siderose (a mineral which is mainly ferrous carbonate but which contains appreciable quantities of the carbonates of manganese and other metals) over the range 87° to 400°K. and some measurements but not actual principal susceptibilities for manganese sulphate, MnSO 4 .4H 2 O. The writer measured the principal susceptibilities of cobalt ammonium sulphate and nickel sulphate, NiSO 4 . 7H 2 O over the temperature range 14°-290°K. and the writer and de Haas have published measurements on manganese ammonium sulphate crystals over the restricted range 14°-20° K. In addition Dupouy has repeated Foëx’s observations on siderose and has measured the principal susceptibilities of dialogite (a naturally occurring manganese carbonate) and oligist (Fe 2 O 3 ), all over a small range of temperature above 0° C. Quite recently Bartlett has employed Rabi’s method to determine the principal susceptibilities of the following compounds, CoSO 4 . 7H 2 O, CoSO 4 . (NH 4 ) 2 SO 4 . 6H 2 O, CoSO 4 . K 2 SO 4 . 6H 2 O, CuSO 4 . (NH 4 ) 2 SO 4 . 6H 2 O CuSO 4 . K 2 SO 4 . 6H 2 O, NiSO 4 . (NH 4 ) 2 SO 4 . 6H 2 O over the temperature range —45° to +55°C. In the writer’s opinion, however, Bartlett’s procedure is liable to several objections.

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