Differential Enthalpies of Solution of Components in Binary Systems 2 CaO . Al2O3 . SiO2-CaO . Al2O3 . 2 SiO2, CaO . SiO2-CaO . Al2O3 . 2 SiO2 and CaO . SiO2-2 CaO . Al2O3 . SiO2

1993 ◽  
Vol 58 (9) ◽  
pp. 1989-1996 ◽  
Author(s):  
Ladislav Kosa ◽  
Ivan Nerád ◽  
Jozef Strečko ◽  
Ivo Proks ◽  
Katarína Adamkovičová

Differential enthalpies of solution of components in binary systems 2 CaO . Al2O3 . SiO2-CaO . Al2O3 . 2 SiO2, CaO . SiO2-CaO . Al2O3 . 2 SiO2 and CaO . SiO2-2 CaO . Al2O3 . SiO2 as the function of composition and temperature were determined on the base of isothermal composition dependences of enthalpies of mixing and temperature dependences of heats of fusion of their pure components. From the values of the first differential heat of solution of CaO . Al2O3 . 2 SiO2 and 2 CaO . Al2O3 . SiO2 in CaO . SiO2 over temperature range considered we can conclude that the reactions were closed chains of SiO4 tetrahedra in CaO . SiO2 melt break, are exothermic. On the other hand positive values of this quantity for CaO . SiO2 in CaO . Al2O3 . 2 SiO2 and 2 CaO . Al2O3 . SiO2 led us to the conclusion that the progressive breaking originally closed chains in CaO . SiO2 melt has endothermic character.

1976 ◽  
Vol 54 (23) ◽  
pp. 3651-3657 ◽  
Author(s):  
Fathi Habashi ◽  
Shaheer A. Mikhail

The reduction of a binary sulfate mixture cannot be predicted from the behavior of the individual components. Thus, while CuSO4 is reduced to Cu at 400 °C and NiSO4 is reduced to Ni3S2, the sulfate mixture yields Cu, Ni3S2, and Cu2S. Also while FeSO4 is completely stable in H2 at 400 °C, (Cu,Fe) SO4 yields Cu and Cu5FeS4. The formation of Cu2S in the first case and Cu5FeS4 in the second was unexpected. On the other hand, (Cu,Mn)SO4 is stable in H2 up to 550 °C although pure CuSO4 is completely reduced at 400 °C. CoSO4 also interferes when reduced in presence of CuSO4, while Na2SO4, MgSO4, Al2(SO4)3, ZnSO4, CdSO4 do not interfere within limited temperature range. Of these only Na2SO4 forms a complex sulfate with CuSO4. No Cu2SO4 was identified when CuSO4 was reduced in presence of other sulfates although it is an intermediate product during the reduction of pure CuSO4.


1992 ◽  
Vol 06 (23n24) ◽  
pp. 3953-3958 ◽  
Author(s):  
Kazuyoshi Tanaka ◽  
Anvar A. Zakhidov ◽  
Kazunari Yoshizawa ◽  
Kenji Okahara ◽  
Tokio Yamabe ◽  
...  

Magnetic properties of C 60 and C 70 complexes with tetrakis(dimethylamino)ethylene (TDAE) have been studied based on the measurements of the Faraday-balance magnetization and the electron spin resonance (ESR). It has been found that both TDAE- C 60 and TDAE- C 70 possess about one radical spin per fullerene molecule. TDAE- C 60 has been confirmed to show ferromagnetic-type transition at Tc=16.7–17.5 K . Appearance of a new broad and intense ESR signal below Tc of TDAE- C 60 suggests that the radical spins in the magnetically ordered state rather localize on each C 60 molecule and are ferromagnetically correlated. On the other hand, TDAE- C 70 does not show ferromagnetism in all the temperature range down to 4.5K.


1971 ◽  
Vol 44 (1) ◽  
pp. 40-51 ◽  
Author(s):  
N. B. Levine

Abstract The nitroso copolymer shows excellent promise which has not been realized due to a lack of ability to achieve a suitable cure. The CNR terpolymer, on the other hand, retains the excellent solvent and oxidizer resistance, nonflammability, and wide useful temperature range of the copolymer and can, in addition, be easily fabricated and cured by several techniques into many useful products.


2018 ◽  
Author(s):  
Wenfa Ng

Temperature affects growth of bacteria by influencing enzyme and growth kinetics. Specifically, evolution selects for specific temperature range in which a microbe could thrive, and thus fix the temperature range in which biomolecule structure and function are finely tuned for coping with the thermal conditions prevailing within a cell at a particular temperature. Using aerobic culture in LB Lennox medium in shake flasks, this study aimed to understand the growth of Pseudomonas protegens Pf-5 (ATCC BAA-477) and Pseudomonas aeruginosa PRD-10 (ATCC 15442) at 25, 30 and 37 oC. Experiment results revealed that P. protegens Pf-5 grew very poorly at 37 oC (with maximal optical density of 0.66), while better growth was observed at 25 and 30 oC. Specifically, P. protegens Pf-5 appeared to be better adapted to growth at 25 oC, where the maximal optical density obtained was 5.3 compared to 4.6 at 30 oC. More importantly, two phase growth behaviour was observed during growth at 30 oC where a faster initial phase of growth was followed by a slower one. Growth at 25 and 30 oC exhibited similar pH trend, which suggested similar metabolic processes was activated during growth. On the other hand, P. aeruginosa PRD-10 demonstrated a more efficient conversion of LB Lennox medium into biomass where the maximal optical density obtained at all three growth temperatures were higher than those of P. protegens Pf-5. More importantly, growth of P. aeruginosa PRD-10 exhibited a clear adaptation to growth at 25 and 37 oC, while growth at 30 oC resulted in a lower biomass yield compared to that of 25 and 37 oC. On the other hand, pH variation during culture revealed that P. aeruginosa PRD-10 likely activated similar metabolic processes at all three growth temperatures, where a higher growth temperature would result in the net secretion of more alkaline metabolites. Collectively, P. protegens Pf-5 and P. aeruginosa PRD-10 demonstrated clear temperature adaptation at an evolutionary level. In addition, experiment data suggested that P. aeruginosa PRD-10 might have co-evolved with humans on a substantial time scale resulting in a temperature preference of 37 oC over 30 oC.


1997 ◽  
Vol 482 ◽  
Author(s):  
K. P. Koron ◽  
A. Wysmolek ◽  
J. M. Baranowskil ◽  
K. Pakul ◽  
J. P. Bergman ◽  
...  

AbstractPhotoluminescence connected with excitons and their phonon replicas in undoped homoepitaxial MOCVD grown GaN layers have been studied in the temperature range 2 - 100 K. It is shown that the coupling between LO phonons and neutral acceptor bound excitons (ABE) is much stronger than the coupling between LO phonons and neutral donor bound excitons (DBE). In spite that emission due the DBE no-phonon is one order of magnitude stronger than the ABE one, the predominant feature of the first LO phonon replica of the excitonic structures is related to the ABE. It is argued that this fact is connected with delocalization of the acceptor wavefunction in the k-space which leads to a higher number of interacting LO phonons in the first replica. On the other hand, the second LO phonon replica of the excitonic structures is predominantly connected with the DBE. In the case of two LO phonons interacting with bound excitons the k - conservation has not so direct influence. In addition, the temperature dependence of LO phonon replicas and their kinetics in ps regime are also reported.


1977 ◽  
Vol 35 ◽  
pp. 141-145
Author(s):  
Alan H. Batten

There are two centres at which papers on spectroscopic binaries are filed and catalogues produced — Toulouse, France and Victoria, B.C., Canada. The aims of these two are somewhat different. At Toulouse a running file of all references to spectroscopic binaries is kept, and many workers have found the comprehensive series of Catalogues Complémentaires (e.g. Pedoussaut and Carquillat 1973) very useful. At Victoria, on the other hand, we concentrate more specifically on spectroscopic determinations of orbital elements, and our catalogue of them was a direct successor of the five such catalogues published by the Lick Observatory. While the Toulouse catalogues are comprehensive, we at Victoria try to make a critical assessment of each orbit we include, and we regard this as one of the most important aspects of our catalogues. Such a critical catalogue obviously cannot be published as frequently as are the Catalogues Complémentaires, which, just as their name implies, are complementary to the Victoria work. There is no fixed interval between the publication of successive Lick-Victoria catalogues. The five from Lick appeared at a mean interval of about a decade, but the transfer to Victoria delayed the appearance of the Sixth Catalogue (Batten 1967) to almost twenty years after that of the Fifth (Moore and Neubauer 1948). After another decade, the Sixth Catalogue is out of date and out of print, and we are well advanced on the preparation of a Seventh, which we hope will appear in 1977. The Sixth Catalogue contained orbital elements for 737 spectroscopic binary systems. About 200 (or 25 per cent) new systems have now to be added, and about one per cent of those already in should be deleted. In addition, new orbital information is available for over 100 of the systems already in the Sixth Catalogue.


2009 ◽  
Vol 635 ◽  
pp. 49-54 ◽  
Author(s):  
Tomoyuki Kakeshita ◽  
Takashi Fukuda ◽  
Tomoyuki Terai ◽  
Toyotaka Osakabe ◽  
Kazuhisa Kakurai

We have investigated stress and temperature dependences of the structure of the X-phase in Ni2MnGa to understand structural relation between the X-phase and other phases. Position and intensity of satellites of the X-phase are different from those of the intermediate (I-) phase under compressive stress, but they approach those of the I-phase with decreasing stress. That is, the structure change associated with the I → X transformation is discontinuous under a compressive stress, while it is continuous under zero stress. In addition, the transformation from the X-phase to the L21-type parent phase is continuous regardless of applied stress. These results strongly suggest the existence of multi-critical point in Ni2MnGa. On the other hand, the transformation from the X-phase to the martensite phase is discontinuous regardless of applied stress.


2018 ◽  
Author(s):  
Wenfa Ng

Temperature affects growth of bacteria by influencing enzyme and growth kinetics. Specifically, evolution selects for specific temperature range in which a microbe could thrive, and thus fix the temperature range in which biomolecule structure and function are finely tuned for coping with the thermal conditions prevailing within a cell at a particular temperature. Using aerobic culture in LB Lennox medium in shake flasks, this study aimed to understand the growth of Pseudomonas protegens Pf-5 (ATCC BAA-477) and Pseudomonas aeruginosa PRD-10 (ATCC 15442) at 25, 30 and 37 oC. Experiment results revealed that P. protegens Pf-5 grew very poorly at 37 oC (with maximal optical density of 0.66), while better growth was observed at 25 and 30 oC. Specifically, P. protegens Pf-5 appeared to be better adapted to growth at 25 oC, where the maximal optical density obtained was 5.3 compared to 4.6 at 30 oC. More importantly, two phase growth behaviour was observed during growth at 30 oC where a faster initial phase of growth was followed by a slower one. Growth at 25 and 30 oC exhibited similar pH trend, which suggested similar metabolic processes was activated during growth. On the other hand, P. aeruginosa PRD-10 demonstrated a more efficient conversion of LB Lennox medium into biomass where the maximal optical density obtained at all three growth temperatures were higher than those of P. protegens Pf-5. More importantly, growth of P. aeruginosa PRD-10 exhibited a clear adaptation to growth at 25 and 37 oC, while growth at 30 oC resulted in a lower biomass yield compared to that of 25 and 37 oC. On the other hand, pH variation during culture revealed that P. aeruginosa PRD-10 likely activated similar metabolic processes at all three growth temperatures, where a higher growth temperature would result in the net secretion of more alkaline metabolites. Collectively, P. protegens Pf-5 and P. aeruginosa PRD-10 demonstrated clear temperature adaptation at an evolutionary level. In addition, experiment data suggested that P. aeruginosa PRD-10 might have co-evolved with humans on a substantial time scale resulting in a temperature preference of 37 oC over 30 oC.


2020 ◽  
Vol 312 ◽  
pp. 3-8
Author(s):  
L. Dermenji ◽  
K.G. Lisunov ◽  
Konstantin Nickolaevich Galkin ◽  
Dmitrii L. Goroshko ◽  
E.A. Chusovitin ◽  
...  

Resistivity, r (T), and Hall coefficient in weak (B < 1 T) magnetic fields, R (T), are investigated in Ca2Si and CaSi2 films at temperatures T between ~ 20 - 300 K. In CaSi2, r (T) is typical of metals increasing with T within the whole temperature range. On the other hand, the resistivity of Ca2Si is pertinent of semiconductors. Namely, it is activated below T ~ 200 K, exhibiting different slopes of ln r vs. T -1 plots at lower and higher T, and a weak increase between T ~ 200 - 300 K. Both materials demonstrate a complex dependence of R (T), including a change of the sign. Transport properties above have been analyzed assuming two groups of charge carriers, electrons and holes, contributing them.


1989 ◽  
Vol 157 ◽  
Author(s):  
F. Dyment ◽  
M. Behar ◽  
H. Oners ◽  
P.L. Grande ◽  
E. Savino ◽  
...  

ABSTRACTThe present contribution reports on measurements of the diffusion coefficients of Hf in a-Zr via the RBS technique. 250 8 Hf thin films were deposited on two kinds of polycrystalIine Zr samples and annealed in a 773-1115 K temperature range. Our results show that in both cases, the diffusion coefficients follow curved flrrhenius plots. On the other hand for the purest Zr sample we have obtained diffusion coefficients that are systematicaly and significativel ly lower than those corresponding to the Zr sample richer in impurities.


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