Thermodynamic properties and phase equilibria in alloys of Bi—Tm system

2021 ◽  
Vol 2021 (3) ◽  
pp. 93-101
Author(s):  
V. S. Sudavtsova ◽  
◽  
V. A. Shevchuk ◽  
V. G. Kudin ◽  
M. I. Ivanov ◽  
...  
Keyword(s):  
Enthalpy Of Mixing ◽  
Thermochemical Properties ◽  
Melt Mixing ◽  
Gibbs Energies ◽  
Temperature Excess ◽  
Ideal Solutions ◽  
Using Data ◽  
Increasing Temperature ◽  
First Time ◽  
Associated Solution

The thermochemical properties of the melts of the Bi—Tm system at a temperature of 1100 K in the range of compositions 0 ≤ xTm ≤ 0,2 were determined for the first time by the calorimetry method. It is established that the minimum value of the enthalpy of mixing of these liquid alloys is equal to –75,7 ± 0,5 kJ / mol at xTm = 0,65. = = –150,7 ± 16,7 kJ / mol, = –230,9 ± 21,8 kJ / mol. The activities of the components and molar particles of associates were calculated according to the model of an ideal associated solution (IAR), using data on the thermochemical properties of melts of the Bi—Tm system. It was found that the activities of the components in these metallic solutions show very large negative deviations from ideal solutions with a high content of TmBi and Tm2Bi associates. The obtained dependences of the first i i melts of the Bi—Tm system on temperature showed a large steepness of the Bi Bi curve in contrast to the gradual decrease of exothermic values Tm of Tm. This indicates large changes in the structure of the Bi atom with increasing temperature. Excess integral and partial Gibbs energies of Bi-Tm system melt mixing calculated from component activities The absolute values of G in the whole concentration range are smaller than H (G min = –41,8 kJ / mol at xTm = 0,58), and the function G of is more asymmetric, which is caused by the entropy contribution (entropy of mixing of the studied melts is negative, and Smin min = −30,5 J / mol ∙ K at xTm = 0,65). Keywords: thermochemical properties, compounds, melts, Bi, Tm.

Thermodynamic properties of melts of Bi—Eu system

2021 ◽  
Vol 2021 (2) ◽  
pp. 90-100
Author(s):  
V. S. Sudavtsova ◽  
◽  
V,A, Shevchuk ◽  
L. O. Romanova ◽  
M. I. Ivanov ◽  
...  
Keyword(s):  
Enthalpy Of Mixing ◽  
Enthalpies Of Formation ◽  
Thermochemical Properties ◽  
Melting Temperatures ◽  
Large Size ◽  
Intermediate Phases ◽  
Ideal Solutions ◽  
First Time ◽  
Enthalpy Data ◽  
The Eu

The thermochemical properties of alloys were determined for the first time by calorimetry Bi—Eu system at a temperature of 1200 K in the range of 0 ≤ xBi ≤ 0,2 and 0,77 ≤ xBi ≤ 1,0. It is established that the minimum value of the enthalpy of mixing is equal to –61,7 ± 0,5 kJ / mol at xBi = 0,5. = –184,7 ± 16,7 kJ / mol, = = –206,9 ± 21,8 kJ / mol. The activities of the components were calculated according to the model of an of the ideal associated solution (IAR), using the thermochemical properties of the melts of the Bі—Eu. system. It has been established that the activities of the components show large negative deviations from ideal solutions. To predict the enthalpies of formation of LnBi compounds, the available literature data on these parameters are analyzed and the most reliable ones are presented as a dependence on ∆fH = f(ZLn). It is established that the enthalpies of formation LnBi change smoothly and monotonically with the exception of Bi—Eu and Bi—Yb systems. This is due to the large size factors for the last two systems. To combine all the enthalpy data of Ln—Bi intermetallic formation of Ln—Bi systems depending on the sequence number Ln, we need similar values for the Eu—Bi compound. But at present they are not known, so based on the above, it was assumed that the value of the minimum enthalpy of mixing will be close to the enthalpy of formation of this compound. This hypothesis is confirmed by data on the enthalpies formation of phase YbBi and equiatomic melts of binary of Yb—Bi system. To confirm the thermodynamic data, we compare the known melting temperatures of the formed intermediate phases, known from the diagrams state Bi—Ln system. The obtained dependences correlate with ∆fH = f(ZLn ) і ∆V = f(ZLn). This means that the predictions of thermochemical properties accurately reflect the nature of the considered melts of the Bi—Eu system. Keywords: thermochemical properties, melts, compounds, Bi, Eu.

scholarly journals The Equilibrium Phase Formation and Thermodynamic Properties of Functional Tellurides in the Ag–Fe–Ge–Te System

Energies ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1314
Author(s):  
Mykola Moroz ◽  
Fiseha Tesfaye ◽  
Pavlo Demchenko ◽  
Myroslava Prokhorenko ◽  
Nataliya Yarema ◽  
...  
Keyword(s):  
Electromotive Force ◽  
Equilibrium Phase ◽  
Stoichiometric Composition ◽  
Negative Electrode ◽  
Electrochemical Cells ◽  
Thermodynamic Quantities ◽  
Positive Electrodes ◽  
Gibbs Energies ◽  
Buffer Region ◽  
First Time

Equilibrium phase formations below 600 K in the parts Ag2Te–FeTe2–F1.12Te–Ag2Te and Ag8GeTe6–GeTe–FeTe2–AgFeTe2–Ag8GeTe6 of the Fe–Ag–Ge–Te system were established by the electromotive force (EMF) method. The positions of 3- and 4-phase regions relative to the composition of silver were applied to express the potential reactions involving the AgFeTe2, Ag2FeTe2, and Ag2FeGeTe4 compounds. The equilibrium synthesis of the set of phases was performed inside positive electrodes (PE) of the electrochemical cells: (−)Graphite ‖LE‖ Fast Ag+ conducting solid-electrolyte ‖R[Ag+]‖PE‖ Graphite(+), where LE is the left (negative) electrode, and R[Ag+] is the buffer region for the diffusion of Ag+ ions into the PE. From the observed results, thermodynamic quantities of AgFeTe2, Ag2FeTe2, and Ag2FeGeTe4 were experimentally determined for the first time. The reliability of the division of the Ag2Te–FeTe2–F1.12Te–Ag2Te and Ag8GeTe6–GeTe–FeTe2–AgFeTe2–Ag8GeTe6 phase regions was confirmed by the calculated thermodynamic quantities of AgFeTe2, Ag2FeTe2, and Ag2FeGeTe4 in equilibrium with phases in the adjacent phase regions. Particularly, the calculated Gibbs energies of Ag2FeGeTe4 in two different adjacent 4-phase regions are consistent, which also indicates that it has stoichiometric composition.

scholarly journals Meteor head echo polarization at 930 MHz studied with the EISCAT UHF HPLA radar

2011 ◽  
Vol 29 (6) ◽  
pp. 1197-1208 ◽  
Author(s):  
G. Wannberg ◽  
A. Westman ◽  
A. Pellinen-Wannberg
Keyword(s):  
Angle Of Incidence ◽  
Resonance Effects ◽  
Observation Volume ◽  
Polarization Characteristics ◽  
Radar Measurements ◽  
Head Echo ◽  
Using Data ◽  
Static Head ◽  
First Time ◽  
Underdense Plasma

Abstract. The polarization characteristics of 930-MHz meteor head echoes have been studied for the first time, using data obtained in a series of radar measurements carried out with the tristatic EISCAT UHF high power, large aperture (HPLA) radar system in October 2009. An analysis of 44 tri-static head echo events shows that the polarization of the echo signal recorded by the Kiruna receiver often fluctuates strongly on time scales of tens of microseconds, illustrating that the scattering process is essentially stochastic. On longer timescales (> milliseconds), more than 90 % of the recorded events show an average polarization signature that is independent of meteor direction of arrival and echo strength and equal to that of an incoherent-scatter return from underdense plasma filling the tristatic observation volume. This shows that the head echo plasma targets scatter isotropically, which in turn implies that they are much smaller than the 33-cm wavelength and close to spherically symmetric, in very good agreement with results from a previous EISCAT UHF study of the head echo RCS/meteor angle-of-incidence relationship. Significant polarization is present in only three events with unique target trajectories. These all show a larger effective target cross section transverse to the trajectory than parallel to it. We propose that the observed polarization may be a signature of a transverse charge separation plasma resonance in the region immediately behind the meteor head, similar to the resonance effects previously discussed in connection with meteor trail echoes by Herlofson, Billam and Browne, Jones and Jones and others.

What drives housing prices, rent and new construction in China

2017 ◽  
Vol 10 (5) ◽  
pp. 662-686
Author(s):  
Dimitrios Staikos ◽  
Wenjun Xue
Keyword(s):  
Real Estate ◽  
Empirical Test ◽  
Housing Prices ◽  
Panel Cointegration ◽  
Real Estate Market ◽  
Estimation Methods ◽  
Content Type ◽  
New Construction ◽  
Using Data ◽  
First Time

Purpose With this paper, the authors aim to investigate the drivers behind three of the most important aspects of the Chinese real estate market, housing prices, housing rent and new construction. At the same time, the authors perform a comprehensive empirical test of the popular 4-quadrant model by Wheaton and DiPasquale. Design/methodology/approach In this paper, the authors utilize panel cointegration estimation methods and data from 35 Chinese metropolitan areas. Findings The results indicate that the 4-quadrant model is well suited to explain the determinants of housing prices. However, the same is not true regarding housing rent and new construction suggesting a more complex theoretical framework may be required for a well-rounded explanation of real estate markets. Originality/value It is the first time that panel data are used to estimate rent and new construction for China. Also, it is the first time a comprehensive test of the Wheaton and DiPasquale 4-quadrant model is performed using data from China.

Morphological and molecular characteristics of Bastiania sinensis sp. n., Tripyla aquatica Brzeski & Winiszewska-Ślipińska, 1993 and T. setifera Bütschli, 1873 (Nematoda: Triplonchida) from Shanxi Province, North China

Nematology ◽  
2021 ◽  
pp. 1-23
Author(s):  
Mei Na Liu ◽  
Yu Mei Xu ◽  
Zeng Qi Zhao ◽  
Jian Ming Wang
Keyword(s):  
North China ◽  
Large Subunit ◽  
Small Subunit ◽  
Rrna Genes ◽  
Shanxi Province ◽  
Molecular Characteristics ◽  
Separate Species ◽  
Using Data ◽  
First Time ◽  
Respective Species

Summary This paper describes a new species of Bastiania, presents a new record and redescribes a known species of Tripyla. These nematodes are all in the order Triplonchida and were collected from Shanxi Province, North China. Bastiania sinensis sp. n. is characterised by having the female with a relatively slender body 1049-1295 μm long, dorsally arcuate after heat relaxation, with outer labial setae and cephalic setae in a single circle, an oval amphid, 7-8 laterodorsal cervical setae scattered in the pharyngeal region, orthometamenes and pseudocoelomocytes present, tail conoid with a mucron 1-2 μm long, two pairs of caudal setae present, a = 58.1-75.5, b = 4.0-4.6, c = 12.7-19.7, c′ = 4.1-7.8 and V = 61.1-67.7. Males were not found. Tripyla aquatica is recorded for the first time from China, and is redescribed. Tripyla setifera has been reported from China but without a detailed description – now provided. In addition, phylogenetic relationships among the species were analysed using data from the near full length small subunit (SSU) and D2-D3 segments of large subunit (LSU) of rRNA genes. Bastiania sinensis sp. n. is monophyletic with the Bastiania sequences available in GenBank, but is on an independent branch supporting its status as a separate species; T. aquatica and T. setifera are monophyletically clustered with known Tripyla species and grouped together with sequences from their respective species.

scholarly journals Prediction of local geomagnetic activity on the example of data of “Lviv” Magnetic Observatory

2021 ◽  
Vol 27 (1) ◽  
pp. 78-84
Author(s):  
D.I. Vlasov ◽  
◽  
A.S. Parnowski ◽  
Keyword(s):  
Predictive Models ◽  
Lead Time ◽  
Measurement Data ◽  
Correlation Coefficients ◽  
Skill Score ◽  
Magnetic Observatory ◽  
Using Data ◽  
First Time ◽  
Prediction Efficiency ◽  
Main Center

For the first time in world practice, predictive models were constructed for X, Y, Z geomagnetic elements. Based on these models, the prediction was made with 3 hours lead time using data of the “Lviv” magnetic observatory. The properties of models are as follows: observatory — LVV, рredicted values — XYZ; lead time — 3 hours; correlation coefficients’ averaged measurement data — 0.824 (X), 0.811 (Y), 0.804 (Z); prediction efficiency — 0.816 (X), 0.803 (Y), 0.801 (Z); skill score — 0.115 (X), 0.095 (Y), 0.099 (Z). The developed models were tested in the Main Center of Special Monitoring, and they were found to meet the Basic Requirements for operational predictive models.

scholarly journals Remote sensing and GPR study of the Raddle glacier of the Ridge Munku-Sardyk (the East Sayan)

2020 ◽  
Vol 26 (2) ◽  
pp. 275-285
Author(s):  
Aleksandr Kitov ◽  
Ivan Denisenko ◽  
Oxana Lunina ◽  
Andrey Gladkov ◽  
Viktor Plyusnin ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Main Part ◽  
Surface Characteristics ◽  
Open Part ◽  
The North ◽  
The Earth ◽  
Using Data ◽  
Eastern Sayan ◽  
Geometric Changes ◽  
First Time

The Munku-Sardyk (Eastern Sayan) glacier has been described and studied for more than 100 years. The first largest glacier of Peretolchina was studied in the most detailed detail. Radde's second-largest glacier is much weaker. Monitoring of surface characteristics of the Radde glacier by ground methods and using data of remote sensing of the Earth (RSE) has been carried out since 2006. In 2018, georadar profiling of this glacier was performed for the first time. As a result, it was possible not only to clarify its surface characteristics, but also to assess the power of the ice and the internal structure (a layer of firn, ice, bed). According to the RSE, its geometric changes have been revealed. Over 120 years, the open part of the Radde Glacier has shrunk from 0.4 to 0.09 km2, and the length from 1 to 0.4 km. It also revealed the division of the glacier into two parts and the intensive reservation of the bottom of the main part of the tongue by surface moraines and the formation of a glacial lake on the glacier itself in the lower part of the second half. Radar research using the Oko-2 georadar, allowed to determine the volume of ice of this glacier 0.003 km3 and the greatest thickness of the main ice body 42 m. The main glacier flows down from the Eskadriliy top, 3168 m, to the north, flows on the cross-bar and from it turns to the northeast, and at the bottom of the kar will continue to flow north again.

JAČANjE PRINCIPA NEUTRALNOSTI INTERNETA KROZ PRAKSU SUDA PRAVDE EU

2021 ◽  
Author(s):  
Sonja Lučić ◽  
Keyword(s):  
Internet Access ◽  
The Internet ◽  
Net Neutrality ◽  
Court Of Justice ◽  
Internet Neutrality ◽  
Using Data ◽  
Treat All ◽  
First Time ◽  
Access Services ◽  
The Eu

In Case C-807/18 the Court of Justice of the EU had the opportunity to interpret Regulation 2015/2120, which contains the principle of Internet Neutrality, for the first time. On this occasion, the Court took position that Internet providers must not favor certain applications and services for providing and using data on the Internet to the detriment of others. The principle of net neutrality existed even before the adoption of Regulation 2015/2120. This Regulation establishes measures concerning open access to the Internet. Namely, the Regulation sets rules aimed at ensuring equality and nondiscriminatory treatement of traffic, as well as protection of the rights of end users. The principle of net neutrality implies that all providers of internet access services will treat all traffic equally without discrimination, restriction or interference and regardless of the sender and recipient, the content accessed or distributed,

Ideal Solutions

1993 ◽  
Author(s):  
Greg M. Anderson ◽  
David A. Crerar
Keyword(s):  
Chemical Constituents ◽  
Physical Nature ◽  
Mechanical Mixture ◽  
The Other ◽  
Free Energies ◽  
Gibbs Energies ◽  
Ideal Solutions ◽  
Solution Reaction ◽  
Spontaneous Reaction ◽  
Trace Components

The chemical constituents of a solution can be varied — added, subtracted and interchanged or substituted for each other — within limits ranging from complete (e.g., gases) to highly restricted (trace components in quartz). Adding or subtracting chemical constituents to or from a phase involves changes in energy, which will be discussed in the following sections. For example, if two components A and B are mixed together, the Gibbs energy of a solution of the two mixed must be less than the sum of the Gibbs energies of the two separately for the spontaneous reaction to take place. That is, if we mix nA moles of component A and nA moles of component B, their combined total G is (nAGA + nBGB) where GA and GB are the molar free energies of A and B. If G(A,B) is the total free energy of the resulting solution, then necessarily if the solution took place spontaneously. Alternatively, dividing through by nA + nB, where XA and XB are the mole fractions. Thus if A is albite and B is anorthite, then (A,B) is plagioclase, and we say that the plagioclase solid solution is more stable than a "mechanical mixture" of grains of albite and anorthite. On the other hand if A is diopside and B is anorthite, little or no mutual solution takes place because in this case so that no spontaneous solution reaction takes place. The term "mechanical mixture" in this context nicely conveys the idea of quantities of mineral grains mixed together and not reacting, but does not work quite so well if A and B are other things such as water and halite, or water and alcohol. Nevertheless, the term is traditionally used no matter what the nature of the solution constituents, and no harm is done as long as we remember that "mechanical mixture" means that the constituents considered do not react with each other, whatever their physical nature.

HIGH TEMPERATURE ULTRA HIGH VOLTAGE SIC THYRISTORS

2010 ◽  
Vol 2010 (HITEC) ◽  
pp. 000167-000173
Author(s):  
R. Singh ◽  
S. Creamer ◽  
E. Lieser ◽  
S. Jeliazkov ◽  
S. Sundaresan
Keyword(s):  
High Temperature ◽  
Voltage Drop ◽  
Carrier Lifetimes ◽  
Edge Termination ◽  
Minority Carrier Lifetimes ◽  
Stable Performance ◽  
Switching Characteristics ◽  
High Yields ◽  
Increasing Temperature ◽  
First Time

Through a systematic study, Silicon Carbide Gate Turn Off (GTO) Thyristors with record performance are demonstrated. Several Anode-Gate interdigitation schemes (raster, hex and involute) were explored to investigate their effect on the static as well as switching characteristics. An optimized edge-termination was employed that resulted in the achievement of near-theoretical forward blocking voltages (>8.1kV), and high yields (>60% on 8mm×8mm) on GTO Thyristors with 60μm/5×1014 cm−3 voltage-blocking epitaxial layers. A low differential specific on-resistance of 2.55 mΩ-cm2, and low on-state voltage drop were measured at 500 A/cm2. High Temperature forward I-V and reverse I-V characteristics show extremely stable performance with temperature, in contrast to state-of-the-art Si GTO Thyristors. Turn-on transient characteristics show a stable delay time of about 400 nano-seconds, and a rise-time that decreases with increasing temperature. Detailed high temperature turn-off measurements conducted using Anode-Switched mode was used to extract the value of minority carrier lifetimes as a function of temperature for the first time.

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