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.

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.

scholarly journals Czochralski growth of mixed cubic sesquioxide crystals in the ternary system Lu2O3–Sc2O3–Y2O3

2021 ◽  
Vol 77 (4) ◽  
Author(s):  
Christian Kränkel ◽  
Anastasia Uvarova ◽  
Émile Haurat ◽  
Lena Hülshoff ◽  
Mario Brützam ◽  
...  
Keyword(s):  
Ternary System ◽  
Czochralski Method ◽  
Optical Quality ◽  
Czochralski Growth ◽  
High Optical Quality ◽  
Melting Temperatures ◽  
Large Size ◽  
Host Materials ◽  
Thermal Investigations ◽  
First Time

Cubic rare-earth sesquioxide crystals are strongly demanded host materials for high power lasers, but due to their high melting points investigations on their thermodynamics and the growth of large-size crystals of high optical quality remain a challenge. Detailed thermal investigations of the ternary system Lu2O3–Sc2O3–Y2O3 revealing a large range of compositions with melting temperatures below 2200°C and a minimum of 2053°C for the composition (Sc0.45Y0.55)2O3 are presented. These reduced temperatures enable for the first time the growth of high optical quality mixed sesquioxide crystals with disordered structure by the conventional Czochralski method from iridium crucibles. An (Er0.07Sc0.50Y0.43)2O3 crystal is successfully grown and characterized with respect to its crystallographic properties as well as its composition, thermal conductivity and optical absorption in the 1 µm range.

Thermodynamic properties of alloys binary In—Pr (Nd) and ternary In—Pr (Nd)—Ni systems

2021 ◽  
Vol 2021 (3) ◽  
pp. 102-108
Author(s):  
A. S. Dudnik ◽  
◽  
V. G. Kudin ◽  
L. O. Romanova ◽  
V. S. Sudavtsova ◽  
...  
Keyword(s):  
Ordinal Number ◽  
Enthalpy Of Mixing ◽  
Enthalpies Of Formation ◽  
Complete Agreement ◽  
Size Factor ◽  
Thermochemical Properties ◽  
Trend Line ◽  
Isoperibolic Calorimetry ◽  
Heavy Lanthanides ◽  
Modern Work

The thermochemical properties of In—Pr system melts in the range of compositions 0 < xIn < 0,4 and In—Nd in the whole concentration range at 1573 ± 1 K were investigated by isoperibolic calorimetry. The obtained data for the In—Pr system melts were extrapolated to the unexplored concentration interval, taking into account that at xPr = 1 the integral and partial mixing for Pr enthalpy are equal to zero. It was found that the first partial for Pr and the minimum enthalpy of mixing are equal to –139 ± 11 and –40,3 ± 0,2 kJ / mol, respectively. For the In—Nd system the first partial for In and Nd, the minimum enthalpy of mixing is equal to −131,7 ± 11, −140,6 ± 12 і –43,3  0,2 kJ / mol, respectively. Comparison of ΔHmin, melts of the five previously studied In—Ln systems from the ordinal number Ln (zLn) together with the data obtained in this work showed that they are described by a single trend line. For ΔHmin of melts of In—Eu (Yb) systems there are very insignificant deviations from the trend line. But for the size factor, these deviations from the trend line are more significant. The enthalpies of formation of some intermetallics of In—Ln systems are known, and most of them belong to the compound LnIn3. But there is no complete agreement between these data. The results of the most modern work show less dependence on the serial number of lanthanide and are more exothermic for heavy lanthanides, compared with other data. Keywords: thermochemical properties, compounds, melts, In, Pr, Nd.

STUDY OF PARENTS 'ATTITUDES ON FITNESS CHILDREN'S VISITS

2018 ◽  
Vol 28 (7) ◽  
pp. 2567-2572
Author(s):  
Ivan Nedelchev
Keyword(s):  
Physical Activity ◽  
Young People ◽  
Online Survey ◽  
Adult Obesity ◽  
Compulsory Schooling ◽  
Strict Diet ◽  
Fitness Training ◽  
First Time ◽  
Active Training ◽  
The Eu

The European report "Bulgaria - Health Profile for the Country 2017" reflects statistics on the obesity and immobilization of young people in the country. Although adult obesity levels are below the EU average, they have increased by 25% since 2008, with statistics showing that among young people they have risen by two-thirds in the 2005-2006 and 2013- 2014 and have reached 20%. Also, more than half of Bulgarian pupils in 1-12 grades (51%) are extremely immobilized, one of the reasons being rare visits to physical education classes and lack of interest in additional sport outside compulsory schooling. Separately, every third grader in Bulgaria has a problem with extra pounds, although in most cases it is the parents who refuse to accept that their child needs change and help, not to mention a strict diet and encouragement to exercise sports. More than 50% of the children who crossed the classrooms for the first time this year in Bulgaria are already having vertebral distortion. Only 3% of Bulgarian teenagers say they sometimes go to the gym because they want to look good and build up muscle mass.However, a positive aspect is that a higher percentage of girls and boys at 15 years of age in Bulgaria report regular physical activity than in other EU countries, although less than 25% report moderate exercise intensive physical activity on a daily basis.This study aims to analyze, on the basis of an authoritative survey, the opinions and the vision of active training parents as to whether their children should be attending fitness training. The survey was conducted within 2 months through an online survey of 21 questions, with a total of 187 active sporting parents. Questions concern both the sporting aspects, the healthy diet and the overall condition of the child, through the eyes of his/her parents.

scholarly journals EU Operational Powers and Legal Protection: A Legal Theory Perspective on the Operational Powers of the European Border and Coast Guard

2021 ◽  
Vol 22 (4) ◽  
pp. 625-649
Author(s):  
Bas Schotel
Keyword(s):  
Legal Theory ◽  
Legal Protection ◽  
European Parliament ◽  
Blind Spot ◽  
Public Law ◽  
Coast Guard ◽  
Public Power ◽  
Legal Constraints ◽  
First Time ◽  
The Eu

AbstractFor the first time in its history, the EU is in the process of acquiring significant and genuine permanent operational powers. A new Regulation on the European Border and Coast Guard provides Frontex with a permanent corps of 10,000 border guards—3,000 of which will be EU agents—its own equipment, and its own competences to intervene along the EU borders and beyond. The operational powers will allow the EU to directly and physically intervene in tangible reality.This Article argues that the conferral of operational powers on the EU poses a risk to individual legal protection. This is because once authorities have acquired operational powers of a certain extent and quality, they can afford to act against or without the law by simply overpowering or eluding the legal mechanisms that normally constrain the exercise of public power. So far, Members of the European Parliament and academics critical of Frontex and the new Regulation have overlooked this issue and concentrated exclusively on how to legally constrain the exercise of operational powers. This Article addresses this blind spot by examining whether and how public law should place legal constraints not only on the exercise but also on the build-up of operational powers.

scholarly journals The notion of ‘employer’: Towards a uniform European concept?

2021 ◽  
pp. 203195252199115
Author(s):  
Matthijs van Schadewijk
Keyword(s):  
Functional Approach ◽  
Working Relationships ◽  
Eu Law ◽  
Member States ◽  
Corporate Groups ◽  
European Legislation ◽  
Contractual Approach ◽  
First Time ◽  
The Eu ◽  
The Way

The growth in multilateral working relationships (e.g. agency work, chains of sub-contracting and corporate groups) is causing Member States to increasingly scrutinise their traditional, contractual approach to the notion of ‘employer’. So far, little attention has been paid to the boundaries and limits that EU law sets when defining the employer. The lack of attention may have come to an end with the recent AFMB judgment, in which the Court ruled, for the first time, that the concept of employer in a provision of EU law had to be given an autonomous and uniform interpretation throughout the EU. Starting from the AFMB judgment, the author analyses the concept of employer in EU law. The author finds that the concept of employer in EU law can be described as ‘uniform in its functionality’: in EU law, the national concept of the employer is never absolute, but the circumstances and the way in which the national concept must be set aside depend on the context and the objective of the European legislation in question. Through this functional approach, EU law partly harmonises the various national approaches to the concept of the employer. Nevertheless, a lack of specific reasoning on the part of the Court may grant the Member States considerable leeway to uphold their own views on the concept.

scholarly journals Mineralogy and Geochemistry of Ultramafic Rocks from Rachoni Magnesite Mine, Gerakini (Chalkidiki, Northern Greece)

Minerals ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 934
Author(s):  
Evangelos Tzamos ◽  
Micol Bussolesi ◽  
Giovanni Grieco ◽  
Pietro Marescotti ◽  
Laura Crispini ◽  
...  
Keyword(s):  
Raw Materials ◽  
Mining Area ◽  
Ultramafic Rocks ◽  
Northern Greece ◽  
Icp Ms ◽  
Time In Literature ◽  
History Of ◽  
First Time ◽  
The Eu

The importance of magnesite for the EU economy and industry is very high, making the understanding of their genesis for the exploration for new deposits a priority for the raw materials scientific community. In this direction, the study of the magnesite-hosting ultramafic rocks can be proved very useful. For the present study, ultramafic rock samples were collected from the magnesite ore-hosting ophiolite of the Gerakini mining area (Chalkidiki, Greece) to investigate the consecutive alteration events of the rocks which led to the metallogenesis of the significant magnesite ores of the area. All samples were subjected to a series of analytical methods for the determination of their mineralogical and geochemical characteristics: optical microscopy, XRD, SEM, EMPA, ICP–MS/OES and CIPW normalization. The results of these analyses revealed that the ultramafic rocks of the area have not only all been subjected to serpentinization, but these rocks have also undergone carbonation, silification and clay alteration. The latter events are attributed to the circulation of CO2-rich fluids responsible for the formation of the magnesite ores and locally, the further alteration of the serpentinites into listvenites. The current mineralogy of these rocks was found to be linked to one or more alteration event that took place, thus a significant contribution to the metallo- and petrogenetic history of the Gerakini ophiolite has been made. Furthermore, for the first time in literature, Fe inclusions in olivines from Greece were reported.

scholarly journals The Thermochemistry of 2,4-Pentanedione Revisited:  Observance of a Nonzero Enthalpy of Mixing between Tautomers and Its Effects on Enthalpies of Formation

2005 ◽  
Vol 109 (25) ◽  
pp. 12590-12595 ◽  
Author(s):  
Manuel Temprado ◽  
Maria Victoria Roux ◽  
Patamaporn Umnahanant ◽  
Hui Zhao ◽  
James S. Chickos
Keyword(s):  
Enthalpy Of Mixing ◽  
Enthalpies Of Formation

scholarly journals Current Challenges of European Integration - 12th Network Europe Conference, 9 – 10 November 2020

2021 ◽  
Author(s):  
André S. Berne ◽  
Jelena Ceranic Perisic ◽  
Viorel Cibotaru ◽  
Alex de Ruyter ◽  
Ivana Kunda ◽  
...  
Keyword(s):  
Member State ◽  
European Integration ◽  
European Commission ◽  
Majority Vote ◽  
Integration Process ◽  
Asylum Policy ◽  
Massive Influx ◽  
The Common ◽  
First Time ◽  
The Eu

Crises are not a new phenomenon in the context of European integration. Additional integration steps could often only be achieved under the pressure of crises.  At present, however, the EU is characterised by multiple crises, so that the integration process as a whole is sometimes being questioned. In 2015, the crisis in the eurozone had escalated to such an extent that for the first time a member state was threatened to leave the eurozone. Furthermore, the massive influx of refugees into the EU has revealed the shortcomings of the Schengen area and the common asylum policy. Finally, with the majority vote of the British in the referendum of 23 June 2016 in favour of the Brexit, the withdrawal of a member state became a reality for the first time. Even in the words of the European Commission, the EU has reached a crossroads. Against this background, the twelfth Network Europe conference included talks on the numerous challenges and future integration scenarios in Europe. 

scholarly journals Brexit and the Reshaping of British Electoral Politics

2019 ◽  
pp. 163-187
Author(s):  
Edward Fieldhouse ◽  
Jane Green ◽  
Geoffrey Evans ◽  
Jonathan Mellon ◽  
Christopher Prosser ◽  
...  
Keyword(s):  
Social Protection ◽  
Free Market ◽  
Electoral Politics ◽  
Social Dimension ◽  
The Social ◽  
Party Support ◽  
Demographic Patterns ◽  
First Time ◽  
Fundamental Shift ◽  
The Eu

In this chapter we show how the vote to leave the EU in 2017 brought about a return to two-party politics and a fundamental shift in the social and geographical alignment of party support. Electoral competition between the two main parties previously dominated by concerns relating to redistribution, taxation, and an emphasis on the free market versus social protection now also focused almost equally on the EU, immigration, and liberal–authoritarian values. For the first time in modern history, economic left–right competition between Labour and the Conservatives was accompanied by a commensurate emphasis on a second cultural, or social, dimension of politics. This was also reflected in changes in the demographic patterns of party support, especially age and education.

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