157 results on '"Equilibrium volume"'
Search Results
2. Analysis of Neuroreceptor Binding In Vivo
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Gjedde, Albert, Bauer, William R., Wong, Dean F., Gjedde, Albert, Bauer, William R., and Wong, Dean F.
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- 2011
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3. Chemical Bonding of Solids
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Wills, John M., Alouani, Mebarek, Andersson, Per, Delin, Anna, Eriksson, Olle, Grechnyev, Oleksiy, Wills, John M., Eriksson, Olle, Andersson, Per, Delin, Anna, Grechnyev, Oleksiy, and Alouani, Mebarek
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- 2010
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4. Aggregate Effective Demand
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Sheehan, Brendan and Sheehan, Brendan
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- 2009
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5. Employment and Unemployment
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Sheehan, Brendan and Sheehan, Brendan
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- 2009
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6. Total energies
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Cardona, Manuel, editor, Fulde, Peter, editor, von Klitzing, Klaus, editor, Queisser, Hans-Joachim, editor, Merlin, Roberto, editor, Störmer, Horst, editor, Zabloudil, Jan, editor, Hammerling, Robert, editor, Weinberger, Peter, editor, and Szunyogh, Laszlo, editor
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- 2005
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7. The determination of radon volumetric activity in atmospheric air and in soil of samarkand and navoi regions
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Sayfiev Sh, K.H Hoshimov, R. M. Eshburiev, D. M. Kholov, A. R. Jurakulov, and A. M. Muzaffarov
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Atmospheric air ,Radionuclide ,chemistry ,Equivalent dose ,Radiochemistry ,Environmental science ,chemistry.chemical_element ,Specific activity ,Equilibrium volume ,Radon ,General Medicine ,Uranium - Abstract
This article presents the results of a study of the concentration and specific activity of various 222 220 radionuclides, such as- Rn, Tn and their variations in the form of the exposure dose rate-EDR, equivalent equilibrium volume activity of radon -EEVAR, long-lived alpha nuclides-LAN in the atmospheric air of the Samarkand and Navoi regions.
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- 2021
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8. The Volume Degree of Freedom in Itinerant Electron Ferromagnetism
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Kim, Duk Joo and Kim, Duk Joo
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- 1999
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9. Assessment of the radiation situation and distribution of radionuclides in the air of the uranium protoxide-oxide calcination shop
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Amrullo M. Muzafarov, Gulchekhra M. Allaberganova, Navoi Mining, Rashid A. Kulmatov, and Metallurgical Factory
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inorganic chemicals ,technology, industry, and agriculture ,Analytical chemistry ,chemistry.chemical_element ,Sampling (statistics) ,Radon ,Equilibrium volume ,Uranium ,complex mixtures ,law.invention ,chemistry ,law ,Environmental science ,Calcination ,Dose rate ,Analysis method - Abstract
The exposure dose rates, the equivalent equilibrium volume activity of radon, and the activity of long-lived alpha-nuclides in the air of the uranium protoxide-oxide calcination shop were determined. Annual effective doses for workers were calculated. Through the use of nuclear-based polietilentereftalata and chemical filters, the disperse composition of particles in the air was studied. The effectiveness of filters in sampling was evaluated for the uranium content. The kinetics of distribution of uranium in various fractions was studied. The quality coefficients of filters that accumulate uranium relative to its norm in various working places of the shop were estimated.
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- 2020
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10. Electronic Structure and Bonding in Ti5Si3
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Ekman, Mathias, Ozoliņš, Vidvuds, Gonis, Antonios, editor, Meike, Annemarie, editor, and Turchi, Patrice E. A., editor
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- 1997
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11. Energetics of the Light Actinides in a Full Charge Density Scheme
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Vitos, L., Kollár, J., Skriver, H. L., Gonis, A., editor, Turchi, P. E. A., editor, and Kudrnovský, Josef, editor
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- 1996
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12. Magnetic Structure in Transition-Metal Compounds
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Moruzzi, V. L., Marcus, P. M., Faulkner, J. S., editor, and Jordan, R. G., editor
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- 1994
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13. Tight-Binding Potentials
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Ducastelle, F., Meyer, Madeleine, editor, and Pontikis, Vassilis, editor
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- 1991
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14. Competition between Osmotic Squeezing versus Friction-Driven Swelling of Gels
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Miyu Seii, Masao Doi, Yoshimi Tanaka, and Tomoki Harano
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Polymers and Plastics ,Science ,Bioengineering ,Equilibrium volume ,General. Including alchemy ,Polyethylene glycol ,010501 environmental sciences ,Viscous liquid ,010402 general chemistry ,01 natural sciences ,Article ,Biomaterials ,cooperative diffusion ,chemistry.chemical_compound ,QD1-65 ,PEG ratio ,medicine ,Osmotic pressure ,QD1-999 ,0105 earth and related environmental sciences ,QD146-197 ,Organic Chemistry ,technology, industry, and agriculture ,0104 chemical sciences ,Chemistry ,chemistry ,Volume (thermodynamics) ,Chemical engineering ,osmotic pressure ,gel dynamics ,Swelling ,medicine.symptom ,Ethylene glycol ,Inorganic chemistry - Abstract
Some types of hydro-gels have almost the same equilibrium swelling volume in water and in ethylene glycol (EG), a highly viscous liquid completely miscible with water. Experiments showed that when a gel fully swollen with EG is immersed into a large amount of water, it temporarily swells up and then relaxes to the equilibrium volume in water. The temporary swelling is explained by the friction force exerted on the gel network from the outward EG flux In this paper, we experimentally show that the temporary swelling is suppressed by adding linear PEG (polyethylene glycol) in the outer water. Although the suppression seems to be explained by the osmotic pressure (i.e., by the same mechanism as the conventional osmotic squeezing), our theoretical analysis reveals that the effect of PEG is much stronger than that expected from the equilibrium osmotic pressure, implying that the PEG chains are condensed on the gel surface.
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- 2021
15. Практика применения индикаторного анализа рынка при разработке стратегии развития жилищного строительства в Хабаровском крае
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Agricultural science ,Equilibrium volume ,Business ,Housing construction ,Earth-Surface Processes - Published
- 2019
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16. Ab initio design of elastically isotropic TiZrNbMoV x high-entropy alloys.
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Tian, Fuyang, Varga, Lajos Karoly, Chen, Nanxian, Shen, Jiang, and Vitos, Levente
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TITANIUM alloys , *ENTROPY , *ELASTIC properties of metals , *ISOTROPIC properties , *REFRACTORY materials - Abstract
Highlights: [•] The refractory high-entropy alloys are studied with ab initio theory. [•] We study the effect of alloying elements on the elastic parameters. [•] We propose an criterion of elastically isotropic refractory high-entropy alloys. [Copyright &y& Elsevier]
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- 2014
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17. Theoretical Study on Equilibrium Volume of Clay Sediments in Salt Solutions
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Tadikonda Venkata Bharat and Dhanesh Sing Das
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Linear relationship ,Hydraulic conductivity ,Specific surface area ,Swelling capacity ,Compatibility (mechanics) ,Soil water ,medicine ,Environmental science ,Equilibrium volume ,Geotechnical engineering ,Swelling ,medicine.symptom - Abstract
Expansive clays exhibit some attractive features such as high swelling capacity and very low hydraulic conductivity, for which it is deemed as the most suitable naturally available material for the design of barrier/buffer material in many geo-environmental engineering practices. Equilibrium sediment volume (ESV) is an important surrogate compatibility test used for assessing the expansiveness of soil. It is also utilized for qualitative understanding of the swelling characteristics of clays, mineral identification, and correlating with different geotechnical properties of clays. A detailed understanding on effect of the influencing parameters on ESV provides useful insights into the fundamental behavior of expansive clays. The main objective of this work was to develop a theoretical model for equilibrium sediment volume of clays in the presence of salt solutions using the concept of diffuse double-layer theory. The ESV showed a linear relationship with the specific surface area of soils.
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- 2020
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18. Coulomb correlation in noncollinear antiferromagnetic α -Mn
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Jianwei Sun, Vladimir V. Sokolovskiy, Olga N. Miroshkina, Mikhail A. Zagrebin, Danil R. Baigutlin, Vasiliy D. Buchelnikov, Aki Pulkkinen, R. S. Markiewicz, Arun Bansil, Erkki Lähderanta, Christopher Lane, Katariina Pussi, Bernardo Barbiellini, and Johannes Nokelainen
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Physics ,Condensed matter physics ,Magnetic moment ,Magnetism ,Degrees of freedom (physics and chemistry) ,Equilibrium volume ,02 engineering and technology ,Spin structure ,equipment and supplies ,021001 nanoscience & nanotechnology ,01 natural sciences ,Phase (matter) ,0103 physical sciences ,Coulomb ,Antiferromagnetism ,010306 general physics ,0210 nano-technology ,human activities - Abstract
We discuss the interplay between magnetic and structural degrees of freedom in elemental Mn. The equilibrium volume is shown to be sensitive to magnetic interactions between the Mn atoms. While the standard generalized gradient approximation underestimates the equilibrium volume, a more accurate treatment of the effects of electronic localization and magnetism is found to solve this longstanding problem. Our calculations also reveal the presence of a magnetic phase in strained $\ensuremath{\alpha}$-Mn that has been reported previously in experiments. This new phase of strained $\ensuremath{\alpha}$-Mn exhibits a noncollinear spin structure with large magnetic moments.
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- 2020
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19. EXPOSURE OF THE PUBLIC OF THE LENINRGAD REGION DUE TO THE NATURAL SOURCES OF IONIZING RADIATION
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O. A. Istorik, L. A. Eremina, A. N. Barkovsky, T. A. Kormanovskaya, and R. R. Akhmatdinov
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State system ,R895-920 ,chemistry.chemical_element ,Radon ,Equilibrium volume ,010501 environmental sciences ,01 natural sciences ,Effective dose (radiation) ,030218 nuclear medicine & medical imaging ,Ionizing radiation ,natural sources of ionizing exposure ,Toxicology ,Medical physics. Medical radiology. Nuclear medicine ,03 medical and health sciences ,0302 clinical medicine ,radiation-hygienic pasportisation and joint state system of control and accounting of the individual doses of the public ,Radiology, Nuclear Medicine and imaging ,QC794.95-798 ,gamma-radiation dose rate ,0105 earth and related environmental sciences ,Radioactivity and radioactive substances ,Radionuclide ,radon ,annual effective dose ,chemistry ,Environmental science ,Dose rate - Abstract
This study is focused on the analysis of the results of the radiation-hygienic passportisation and the Joint state system of control and accounting of the individual doses of the public from natural sources of ionizing radiation in the Leningrad region. The results of the study include data on the number of measurements of the gamma-radiation dose rate in buildings and in open territories, number of measurements of volume activity and equivalent equilibrium volume activity of radon in the air in the public and residential buildings in the Leningrad region in 2007–2016 as well as the number of the assessments of the total volume alpha and beta activity and concentration of the natural occurring radionuclides in drinking water. The authors performed an assessment of the annual individual effective dose per resident of theLeningradregion. It was estimated as 3.09 mSv/year considering all the data in Regional dose databank. Natural sources of ionizing exposure contribute 92.6% to the annual effective dose to the public of the Leningrad region, that exceeds the average Russian values by 6%.
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- 2018
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20. Coexistence of Type-I and Type-II Weyl Points in the Weyl-Semimetal OsC2
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Minping Zhang, Zongxian Yang, and Guangtao Wang
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Physics ,Condensed matter physics ,Weyl semimetal ,Equilibrium volume ,02 engineering and technology ,Electron ,Type (model theory) ,021001 nanoscience & nanotechnology ,01 natural sciences ,Semimetal ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,General Energy ,0103 physical sciences ,Condensed Matter::Strongly Correlated Electrons ,Physical and Theoretical Chemistry ,010306 general physics ,0210 nano-technology ,Fermi Gamma-ray Space Telescope - Abstract
The topologically nontrivial Weyl semimetals have two different types: (i) the standard Weyl cones with point-like Fermi surfaces (type-I) and (ii) tilted Weyl cones that appear at the contact of electron and hole pockets (type-II). These two types of Weyl semimetals have significantly different physical properties in their thermodynamics and magnetotransport. Here we presented a compound OsC2 with both types Weyl points (WPs) at the equilibrium volume. It has 24 type-I WPs in the Kz = ±0.0241 ×2πc planes around K (or K′) points and 12 type-II WPs in the Kz = ±0.4354 ×2πc planes at the projected K (K′) point, respectively. The type-I WPs are connected by the helix-trimer Fermi arcs.
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- 2018
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21. Effect of alloying elements on the stacking fault energies of dilute al-based alloys
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Shun Li Shang, Yong Du, R. Yang, Qiannan Gao, H. Zhang, Yu Liu, Zi Kui Liu, Y. Gao, J. Wang, Z. Fan, and X. Geng
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lcsh:TN1-997 ,Work (thermodynamics) ,Materials science ,Al-based alloys ,Metals and Alloys ,Analytical chemistry ,Equilibrium volume ,first-principles ,02 engineering and technology ,stacking fault energy ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Geotechnical Engineering and Engineering Geology ,01 natural sciences ,alloying element ,0104 chemical sciences ,Mechanics of Materials ,Stacking-fault energy ,Materials Chemistry ,0210 nano-technology ,lcsh:Mining engineering. Metallurgy ,Stacking fault - Abstract
A systematic study of the stacking fault energy (?SF) for the dilute Al-based alloys (Al23X, Al47X and Al71X, where X = Al, Ag, Be, Ca, Cd, Co, Cu, Cr, Fe, Ga, Ge, Hf, In, K, La, Li, Mn, Mg, Ni, Na, Pb, Sc, Sn, Sr, Si, Ti, V, Zn, and Zr) has been performed by means of first-principles calculations. Alias shear deformation is adopted in the present investigations. The presently calculated ?SF for Al is in favorable accordance with experimental and other theoretical data. For the targeted elements, the calculations indicate that Na, Si, K, Ca, Sc, Ga, Ge, Sr, Zr, In, Sn, La, Hf, and Pb, in any concentration we considered, decrease the ?SF of Al, while Ag, Be, Cd, Co, Cu, Cr, Fe, Li, Mn, Mg, Ni, Ti, V, and Zn increase the ?SF of Al, when the concentration of alloying elements is 1.39 at. % in the system. With increasing concentration of alloying elements, Li, Mg, V, Ti, and Cd change from increasing the ?SF of Al to decreasing it, based on present investigations. Among the alloying elements, which decrease the ?SF of Al, La decreases the ?SF most significantly. It is also found that the ?SF of Al-X generally decreases with the increase of equilibrium volume. The results obtained in the present work provide an insight into the design of Al based alloys.
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- 2018
22. Electronic structure of RTAl (R=Y, Lu; T=Ni, Cu and Pd) compounds
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Diviš, M. and Javorský, P.
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ELECTRONIC structure , *ALUMINUM compounds , *RARE earth metal compounds , *DENSITY functionals , *ELECTRON distribution , *CHEMICAL equilibrium , *ENERGY bands - Abstract
Abstract: First-principles calculations based on density-functional theory were performed for the first time on RTAl (R=Y, Lu, T=Ni, Cu, Pd) compounds. The electronic density of states and equilibrium volume were studied using the relativistic full-potential APW plus local-orbitals calculations and compared with the experimental data available. [Copyright &y& Elsevier]
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- 2010
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23. Morphodynamics and Sand Bypassing at Ameland Inlet, The Netherlands.
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Kwok Fai Cheung, Gerritsen, Franciscus, and Cleveringa, Jelmer
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LITTORAL drift , *SAND bars , *SAND waves , *SEDIMENTARY structures , *SAND & gravel quarries & quarrying , *SIMULATION methods & models , *INLETS - Abstract
In this paper, we review and analyze the cyclic morphodynamics and sand-bypassing processes at the Ameland Inlet, The Netherlands. The inlet is located between the islands of Terschelling and Ameland in the Dutch Wadden Sea. The bypassing rate and sand storage have a periodicity of 50 to 60 years in connection with the migration of the channels in the inlet and the transformation of the gorge between a one-channel and a two-channel system. These developments modulate the volumes of the shoal and bypassing bars and produce an attenuating sand wave toward the downdrift coast. An aggregate model is developed to describe the inlet morphology at this intermediate timescale. The model is based on a modified equilibrium-volume approach, which allows erosion and accretion of the shoal and bars to occur about their long-term equilibrium. The model results depict observed morphologic behaviors of the inlet and corroborate the measured modulation of the downdrift coastline. The simulation of the effect of the 1979 and 1980 sand mining operations in the ebb tidal delta reproduces the reported rapid recovery of the sandpits and illustrates the capabilities of the model as an inlet planning and management tool. [ABSTRACT FROM AUTHOR]
- Published
- 2007
24. Physicochemical approach for analyzing equilibrium volume of clay sediments in salt solutions
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Dhanesh Sing Das and Tadikonda Venkata Bharat
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Nacl solutions ,Diffuse double layer ,0211 other engineering and technologies ,Mineralogy ,020101 civil engineering ,Geology ,Equilibrium volume ,02 engineering and technology ,Parallel plate ,0201 civil engineering ,Geochemistry and Petrology ,Soil water ,Bentonite ,Clay minerals ,Expansive ,021101 geological & geomatics engineering - Abstract
Equilibrium sediment volume (ESV) is used as an important parameter for understanding the expansive nature of the bentonites and natural clay soils, for assessing a given bentonite for engineering applications, and for the determination of the type of dominant clay mineral present in a given soil. The ESV is often estimated using different salt solutions to understand the compatibility of given clay soil for long-term engineering application such as landfills. A theoretical approach based on physicochemical behavior of clays was proposed in this paper for the estimation of equilibrium sediment volume of bentonites in the presence of salt solutions. A simple analytical expression relating equilibrium sediment volume with different influencing physicochemical parameters such as clay surface and pore-fluid parameters was presented using the diffuse double layer theory. A quantitative estimation of ESV by the proposed theory was validated on the measured data. A very good agreement between the theoretical and measured data was observed for the commercial bentonite. The theory was in good agreement with the measurements in the concentration range of 0.01 M ≤ n < 1 M for Kutch bentonite while the concentration range was 0.001 M ≤ n < 1 M for Barmer bentonite in NaCl solutions. The influence of different exchangeable cations and the presence of non-clay content on the prediction were analyzed with a great detail using theory and by comparing the ESV data of studied bentonites with the homoionic sodium clay. The parallel plate assumption made in the theory overestimated the ESV data in CaCl2 solution. The proposed analytical model is very useful for understanding the influencing parameters on the bentonite behavior.
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- 2017
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25. Doses from radon-222 irradiation for workers of the granite mining industry
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Yu Tomilin and L Сrygorieva
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Chronic exposure ,chemistry.chemical_element ,Equilibrium volume ,Radon ,Radionuclide dose ,Effective dose (radiation) ,030218 nuclear medicine & medical imaging ,Radiation exposure ,03 medical and health sciences ,Mining industry ,0302 clinical medicine ,chemistry ,030220 oncology & carcinogenesis ,Environmental health ,Environmental science ,Radiology, Nuclear Medicine and imaging ,Irradiation - Abstract
Objective determining the integral value of annual effective dose from 222Rn for workers of the granite mining industry and assessment for the expected life effective dose from 222Rn. Materials Materials were the results of measurements of external exposure dose of radiation measurements equiv alent equilibrium volume activity of 222Rn in workrooms and workplaces of major groups of granite quarry workers Mykolaiv region, studies EROA 222Rn air premises of these workers, research content 222Rn in drinking water. Results and conclusions Granite quarry workers receive double radiation exposure of 222Rn due to exposure in the workplace and at home. The load in the workplace due to inhalation of 222Rn the air was (2.1 ± 0.2) mSv / year (vari ation 0.9-5.9) in a residential area - (4,1 ± 0,2) mSv/year (variation 1.8-5.9). The total annual effective dose from internal exposure from air flow and working premises and drinking water was on average (6,5 ± 0,2) mSv/year, equal to a maximum value of 20 mSv/year. The expected life for the chronic exposure dose of technological naturally occurring radioactive sources for people who work in the granite quarries and, while living in high risk from radon is in the range of 0.16-1.12 Sv. The research results indicate that in assessing the effects associated with exposure due to radon 222 contingents persons such surveys must take into account all sources of this radionuclide dose.
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- 2017
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26. Site-specific concentration of uranium in urine of workers of the hydrometallurgical plant of Stepnogorsk mining and chemical combine
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Polat Кazymbet, Meirat Bakhtin, Кassym Zhumadilov, Elena A. Shishkina, Nursulu Altaeva, Moldir Aumalikova, and Danara Ibrayeva
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Adult ,Male ,Biophysics ,chemistry.chemical_element ,Equilibrium volume ,Radon ,Pilot Projects ,Urine ,Radiation Dosage ,Effective dose (radiation) ,Mining ,Ionizing radiation ,Toxicology ,Radiation Monitoring ,Occupational Exposure ,Humans ,General Environmental Science ,Aged ,Radiation ,Uranium ,Middle Aged ,Alpha Particles ,Kazakhstan ,chemistry ,Metallurgy ,Environmental science ,Radiation monitoring ,Dose rate ,Biological Monitoring - Abstract
Radiation monitoring is an important radiation safety measure implemented at the hydrometallurgical plant of the Stepnogorsk mining and chemical combine (HMP SMCC, Republic of Kazakhstan). Follow-up of the workers and their regular medical examinations has laid the basis to create a cohort with the potential to be used in radiation epidemiology. The aim of current pilot study was to analyze the dose forming factors for workers of HMP SMCC. For this, bioassays samples collected from 54 workers employed at eight HMP workshops were measured using the "Agilent 7800 ICP-MS" mass spectrometer. Three years later, measurements were repeated for four workers with the highest concentrations of uranium in urine. The results of site-specific measurements of dose rates, long-lived alpha-particle activity concentrations and equivalent equilibrium volume activity of radon were derived from the archive of the HMP SMCC Service of Radiation and Toxic Safety and analyzed to fully evaluate the radiation situation at those workplaces. Maximum urine uranium concentrations were measured for workers at the extraction workshop and mechanical repair shop (up to 26.7 µg/L and 14.6 µg/L, respectively). Urinary uranium from workers employed at other sites was mainly (for about 72% of the samples) in the range of values that may occur in natural conditions (
- Published
- 2019
27. Electronic and vibrational properties of Pu3M(M=Al, Ga, In, and Tl) : A first-principles study
- Author
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Cong Wang, Yu Yang, Ping Zhang, Menglei Li, and Fawei Zheng
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Physics ,Brillouin zone ,Metal ,Condensed matter physics ,Bond strength ,Phonon ,Molecular vibration ,visual_art ,Doping ,visual_art.visual_art_medium ,Condensed Matter::Strongly Correlated Electrons ,Equilibrium volume ,Coupling (probability) - Abstract
We investigated the structural, electronic, magnetic, and phonon properties of ${\mathrm{Pu}}_{3}M$, where $M$ = Al, Ga, In, and Tl, using first-principles calculations with the spin-orbit coupling taken into consideration. All four compounds are found to contain transverse phonons along [011] and [111] that remarkably soften at the boundaries of the first Brillouin zone, corresponding to the $\mathrm{M}$ and $\mathrm{R}$ points. Through detailed analyses of the vibrational modes and bond strengths, we reveal that all four types of $M$ atoms have softer bonding with neighboring Pu than Pu-Pu bond, which accounts for the phonon softening and may shed light on the $\ensuremath{\delta}$-stabilization of Pu by trivalent metal doping. In addition, we find that, due to the missing $p\text{\ensuremath{-}}d$ hybridization, ${\mathrm{Pu}}_{3}\mathrm{Al}$ behaves quite differently from the other three ${\mathrm{Pu}}_{3}M$ compounds. For example, ${\mathrm{Pu}}_{3}\mathrm{Al}$ has an unexpected equilibrium volume and high-frequency disentangled optical branches of phonons.
- Published
- 2019
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28. Prediction on Elastic Properties of Nb-doped Ni Systems
- Author
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Zhibin Gao, Beibei He, Lu Lin, Jia Song, Wenheng Wu, and Liang Zhang
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Materials science ,General Chemical Engineering ,Enthalpy ,Thermodynamics ,FOS: Physical sciences ,Equilibrium volume ,02 engineering and technology ,01 natural sciences ,Shear modulus ,0103 physical sciences ,Mesoscale and Nanoscale Physics (cond-mat.mes-hall) ,General Materials Science ,Bulk modulus ,Condensed Matter - Materials Science ,010304 chemical physics ,Condensed Matter - Mesoscale and Nanoscale Physics ,Materials Science (cond-mat.mtrl-sci) ,General Chemistry ,Disordered Systems and Neural Networks (cond-mat.dis-nn) ,Condensed Matter - Disordered Systems and Neural Networks ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,Nb doped ,Modeling and Simulation ,0210 nano-technology ,Constant (mathematics) ,Information Systems - Abstract
On the basis of the first principles simulation, the structure, formation enthalpy, and mechanical properties (elastic constant, bulk, and shear modulus and hardness) of five Nb-doped Ni systems are systematically studied. The calculated equilibrium volume increases with the Nb concentration increasing. The computational elastic constants and formation enthalpy indicate that all Nb-doped Ni systems are mechanically and thermodynamically stable in our research. The hardness of these systems also be predicted after the bulk modulus and shear modulus have been accurately calculated. The results show that the hardness increases with the Nb concentration increasing when the Nb concentration below 4.9%, beyond which the hardness will decrease within the scope of our study., 21 pages, 6 figures, 5 tables
- Published
- 2019
29. Structural, electronic and magnetic properties of Fe2-based full Heusler alloys: A first principle study
- Author
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S. Bin Omran, Bendouma Doumi, Rabah Khenata, F. Dahmane, Abdelkader Tadjer, D. P. Rai, Ghulam Murtaza, Dinesh Varshney, and Y. Mogulkoc
- Subjects
010302 applied physics ,Nial ,Materials science ,Magnetic moment ,Condensed matter physics ,First principle study ,Plane wave ,Equilibrium volume ,02 engineering and technology ,Electronic structure ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,01 natural sciences ,Electronic, Optical and Magnetic Materials ,Metal ,Crystallography ,Ab initio quantum chemistry methods ,visual_art ,0103 physical sciences ,visual_art.visual_art_medium ,0210 nano-technology ,computer ,computer.programming_language - Abstract
Using the first-principles density functional calculations, the structural, electronic and magnetic properties of the Fe 2 XAl (X=Cr, Mn, Ni) compounds in both the Hg 2 CuTi and Cu 2 MnAl-type structures were studied by the full-potential linearized augmented plane waves (FP-LAPW) method. The exchange and correlation potential is treated by the generalized-gradient approximation (GGA) where the results show that the Cu 2 MnAl-type structure is energetically more stable than the Hg 2 CuTi-type structure for the Fe 2 CrAl and Fe 2 MnAl compounds at the equilibrium volume. The full Heusler compounds Fe 2 XAl (X=Cr, Mn) are half-metallic in the Cu 2 MnAl-type structure. Fe 2 NiAl has a metallic character in both CuHg 2 Ti and AlCu 2 Mn-type structures. The total magnetic moments of the Fe 2 CrAl and Fe 2 MnAl compounds are 1.0 and 2.0 μ B , respectively, which are in agreement with the Slater–Pauling rule M tot =Z tot − 24.
- Published
- 2016
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30. Ab initio study of the parent (BCC) and martensitic (HCP) phases of nonferrous Ti, Zr, and Hf metals
- Author
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T. Chihi, Messaoud Fatmi, B. Ghebouli, and M.A. Ghebouli
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Bulk modulus ,Materials science ,Ab initio ,General Physics and Astronomy ,Thermodynamics ,Modulus ,Equilibrium volume ,02 engineering and technology ,Crystal structure ,021001 nanoscience & nanotechnology ,01 natural sciences ,Shear modulus ,Condensed Matter::Materials Science ,Martensite ,0103 physical sciences ,Density functional theory ,010306 general physics ,0210 nano-technology - Abstract
We present calculations of the structural, elastic and electronic properties of nonferrous Ti, Zr, and Hf pure metals in both parent and martensitic phases in bcc and hcp structures respectively. They are based on the generalized gradient approximation (GGA) within the density functional theory. The shear modulus, Young's modulus and Poisson's ratio for Ti, Zr, and Hf metals have were calculated and compared with the corresponding experimental values. Using elastic constants obtained from calculations under the GGA, the bulk modulus along the crystallographic axes of single crystals is calculated. This is in good agreement with experiment for Ti and Zr, whereas the hcp structure for Hf is a prediction. At zero temperature and zero pressure, the bcc crystal structure is found to be mechanically unstable for Ti, Zr, and Hf. In our calculations the hcp structure is correctly found to be stable at the equilibrium volume. In the electronic density of states, the smaller n(EF) is, the more stable the compound is, in agreement with the results obtained from the total energy minimum.
- Published
- 2016
- Full Text
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31. Annual individual hygienic assessment of natural exposure doses of the Altai territory model areas population
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N. Yu. Potseluev, I. P. Saldan, B. A. Balandovich, O. V. Okolelova, and S. P. Filippova
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Radioactivity and radioactive substances ,geography ,Radionuclide ,education.field_of_study ,the radiation factor ,geography.geographical_feature_category ,Steppe ,Radiation dose ,Population ,R895-920 ,chemistry.chemical_element ,radon ,Radon ,Equilibrium volume ,Effective dose (radiation) ,Medical physics. Medical radiology. Nuclear medicine ,chemistry ,Radiology, Nuclear Medicine and imaging ,QC794.95-798 ,Physical geography ,Population exposure ,radiation dose ,education ,Cartography ,model area - Abstract
The goal is to determine ionizing radiation natural sources exposure regularities of Altai Territory model areas population. The materials and methods. 11376 radon measurements, 1247 gamma radiation meas-urements in an open area and in residential and office buildings were performed, selection of 189 drinking water tests was carried out. Results. Complex radiation and hygienic examination of the region with the most large municipalities number with model areas allocation was conducted. The assessment of the Altai Territory population’s individual annual radiation doses from natural radionuclides has revealed a number of the regularities depending on the terrain’s ecological and geographical type. Following the research results, ranging the region territories taking into account of annual effective doses of the population from natural sources for 2009-2015 was carried out. The annual individual effective dose of the Altai Territory upland areas population presented by the highest values and ranges from 7.36 mSv / year to 8.19 mSv / year. Foothill regions of Altai and in Salair ridge are characterized by increased population exposure from natural sources. Here the dose ranges from 5.09 mSv / year to 6.22 mSv / year. Steppe and forest-steppe territories are characterized by the lowest level of the natural radiation which is ranging from 3.23 mSv / year to 4.11 mSv / year, that doesn’t exceed the all-Russian levels. Most of the hygienic radon equivalent equilibrium volume activity standards exceedances were registered in mountain and foothill areas buildings. A number of radon anomalies is revealed also in steppe areas. Med exceedances ranged from 203 ± 17.8 Bq / m3 to 480 ± 37.9 Bq / m3. Given the fact that most of these buildings belong to the administrative or educational institutions with an eight-hour working day, the dose of radiation for people there can be up to 10 mSv / year. Conclusion. Spreading of individual annual effective dose of the Altai Territory population showed that five regions of the model areas are converted into three main groups depending on the natural radiation dose due primarily radon equivalent equilibrium volume activity and depends mostly on the eco-geographical terrain type.
- Published
- 2016
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32. Compressibility of BiCu 2 PO 6 : Polymorphism against S = 1 / 2 Magnetic Spin Ladders
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Alexander A. Tsirlin, Olivier Mentré, Céline Darie, Claire V. Colin, Anton Jesche, Marie Colmont, Unité de Catalyse et Chimie du Solide - UMR 8181 (UCCS), Centrale Lille Institut (CLIL)-Université d'Artois (UA)-Centrale Lille-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Lille, Matériaux, Rayonnements, Structure (MRS), Institut Néel (NEEL), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Center for Electronic Correlations and Magnetism, Universität Augsburg [Augsburg], Université d'Artois (UA)-Centrale Lille-Institut de Chimie du CNRS (INC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS), Matériaux, Rayonnements, Structure (NEEL - MRS), and ANR-16-CE08-0023,LOVE-ME,Couplages Magnéto-Electriques exacerbés dans des matériaux à unités ferromagnétiques(2016)
- Subjects
Condensed matter physics ,Chemistry ,Equilibrium volume ,02 engineering and technology ,021001 nanoscience & nanotechnology ,01 natural sciences ,Spin magnetic moment ,Inorganic Chemistry ,Polymorphism (materials science) ,Differential thermal analysis ,Metastability ,0103 physical sciences ,Compressibility ,[PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci] ,Physical and Theoretical Chemistry ,[PHYS.COND.CM-SCE]Physics [physics]/Condensed Matter [cond-mat]/Strongly Correlated Electrons [cond-mat.str-el] ,010306 general physics ,0210 nano-technology ,Ground state ,Quantum ,ComputingMilieux_MISCELLANEOUS - Abstract
BiCu2PO6 is a unique example of a S = 1/2 ladder where the magnetic exchanges are mainly confined in 1D ∞[BiCu2O2]3+ cationic ribbons, although the shortest Cu-Cu separation between them exists. Its original magnetic topology gives the most representative example of a frustrated quantum ladder to investigate the complex physics behind it. Herein, we report the synthesis and characterization of one high-pressure polymorph. In this new phase, the preservation of 1D ∞[BiCu2O2]3+ units somewhat restacked leads to the preservation of its gapped magnetic ground state and ladder topology. The comparison of both compounds highlights the start of a thermodynamic conjuncture, where both the stable ambient-pressure (AP) and metastable high-pressure (HP) forms display the same equilibrium volume and superposed volume dependence of the energy, leading to a first-order AP → HP transition undetected by differential thermal analysis.
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- 2018
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33. Phase stability of α-, γ-, and ε-Ce: DFT+DMFT study
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V. I. Anisimov, M. A. Korotin, Alexey O. Shorikov, and Sergey V. Streltsov
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Physics ,Wannier function ,Physics and Astronomy (miscellaneous) ,Condensed matter physics ,Solid-state physics ,Phase stability ,Cell volume ,Equilibrium volume ,01 natural sciences ,010305 fluids & plasmas ,Condensed Matter::Materials Science ,Tetragonal crystal system ,0103 physical sciences ,Physics::Atomic and Molecular Clusters ,Coulomb ,Condensed Matter::Strongly Correlated Electrons ,010306 general physics ,Phase diagram - Abstract
We present the total energy calculation of α-, γ-, and e-Ce phases in the frame of GGA, GGA+U, and DFT+DMFT methods. It has been shown that taken into account of Coulomb correlations in the frame of dynamical mean-field theory allows reproducing the phase diagram of Ce in correct way. Equilibrium volume calculated within the DFT+DMFT method for face-centered cubic (fcc) structure agrees with experimental Ce-γ cell volume. With temperature decrease energy minimum shifts toward α cell volume. Moreover, the DFT+DMFT total energy for body-centered tetragonal (bct) structure becomes smaller than for fcc one with increase in pressure in agreement with experimental phase diagram. Importance of accounting of Coulomb correlation in the frame of DMFT is discussed.
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- 2015
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34. Effect of ruthenium on the precipitation of topologically close packed phases in Ni-based superalloys of 3rd and 4th generation
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Dierk Raabe, Julian George Müller, Kamil Matuszewski, Pyuck-Pa Choi, Ralf Rettig, Ivan Povstugar, Erdmann Spiecker, Krzysztof J. Kurzydłowski, Zirong Peng, H. Matysiak, and Robert F. Singer
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Materials science ,Polymers and Plastics ,Precipitation (chemistry) ,Metals and Alloys ,chemistry.chemical_element ,Thermodynamics ,Equilibrium volume ,Instability ,Electronic, Optical and Magnetic Materials ,Ruthenium ,Matrix (geology) ,Superalloy ,Crystallography ,Tetragonal crystal system ,chemistry ,Phase (matter) ,Ceramics and Composites - Abstract
The precipitation of topologically close packed (TCP) phases is detrimental for the high temperature strength of high refractory Ni-based superalloys. The beneficial influence of Ru with respect to this so called instability is nowadays well accepted. In the present paper the precipitation of topologically close packed (TCP) phases is studied quantitatively in two experimental alloys (one Ru-free and one with addition of Ru) to clarify the mechanism of the Ru effect. It is confirmed that the TCP phase precipitates undergo sequential phase transformation with the tetragonal σ-phase precipitating first. Ru retards the phase transformation and leads to decreased equilibrium volume fraction of TCP phases. The results clearly indicate that Ru decreases the driving force for TCP phase precipitation. Investigations of crystallography and chemistry of the TCP/matrix interface point to an additional effect by increase of misfit strain energy.
- Published
- 2015
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35. Generalized stacking fault energy, ideal strength and twinnability of dilute Mg-based alloys: A first-principles study of shear deformation
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Suveen N. Mathaudhu, Shun Li Shang, Laszlo J. Kecskes, Zi Kui Liu, William Yi Wang, Yi Wang, Bi Cheng Zhou, and Kristopher A. Darling
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Materials science ,Polymers and Plastics ,Metals and Alloys ,Stacking ,Charge density ,Thermodynamics ,Equilibrium volume ,Electronic, Optical and Magnetic Materials ,Crystallography ,Shear (geology) ,Stacking-fault energy ,Lattice (order) ,Ceramics and Composites ,Crystal twinning ,Stacking fault - Abstract
In an effort to establish a scientific foundation for the computational development of advanced Mg-based alloys, a systematic study of the generalized stacking fault (GSF) energy curves has been undertaken. Additionally, the associated stable and unstable stacking and twinning fault energies, ideal shear strengths, and comparative twinnability have been investigated in terms of first-principles calculations for dilute Mg-based alloys of type Mg 95 X. These GSF properties are predicted using the simple and especially the pure alias shear deformations on the basal (0 0 0 1) plane and along the [ 1 0 1 ¯ 0 ] direction of the hexagonal close-packed (hcp) lattice. Fourteen alloying elements (X) are considered herein, namely Al, Ca, Cu, La, Li, Mn, Sc, Si, Sn, Sr, Ti, Y, Zn and Zr. The following conclusions are obtained: (i) the fault energies and the ideal shear strengths of Mg 95 X alloys decrease approximately linearly with an increasing equilibrium volume of X (or Mg 95 X), with the exceptions being for alloying elements Al, Cu, Si and Zn; (ii) alloying elements Sr and La greatly increase the twin propensity of hcp Mg, while Mn, Ti and Zr exhibit opposite trends; and (iii) the observed variation in GSF properties for hcp Mg caused by alloying elements X can be directly traced to the distribution of the differential charge density (Δ ρ )—a spherical distribution of Δ ρ facilitates the redistribution of charge and shear deformation, resulting in lower shear-related properties, such as stacking fault energy and ideal shear strength. Computed GSF properties of Mg 95 X are shown to agree with available experimental and other theoretical results in the literature.
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- 2014
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36. Electronic, mechanical and optical properties of Y2O3 with hybrid density functional (HSE06)
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Muhammad Ramzan, Raghuveer Chimata, Yan-Ling Li, and Rajeev Ahuja
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Bulk modulus ,Materials science ,General Computer Science ,Band gap ,General Physics and Astronomy ,Thermodynamics ,Equilibrium volume ,General Chemistry ,Electronic structure ,Moduli ,Computational Mathematics ,Generalized gradient ,Mechanics of Materials ,Computational chemistry ,Lattice (order) ,General Materials Science ,Yttria-stabilized zirconia - Abstract
In this paper, we have investigated the electronic, optical and mechanical properties of the Y 2 O 3 crystal by first-principle calculations based on the density–functional theory. The generalized gradient approximation (GGA-PBE) and hybrid exchange–correlation functional (HSE06) are both used for comparative study. It is found that, the band gap of Y 2 O 3 calculated by HSE06 method (6.0 eV) is in good agreement with the experimental band gap data (5.5 eV), and HSE06 gives better electronic structure description close to experiments. Then we calculate the elastic constants, and derive the corresponding properties i.e.; bulk, shear and Young’s moduli, and Poisson’s ratio. Our calculated elastic and mechanical properties correspond well with experimental data. Besides, we also obtain the equilibrium lattice and bulk modulus of yttria by fitting the Birch–Murnaghan equation of state. It is found that, the HSE06 well reproduce the experimental lattice parameters, equilibrium volume and bulk modulus of Y 2 O 3 . Based on the accurate described crystal and electronic structure and mechanical properties by HSE06 method, the optical properties of this material are also analyzed.
- Published
- 2013
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37. Gels
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Tanaka, Toyoichi and Nicolini, C., editor
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- 1987
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38. Equilibrium Volume and Passive Pressure-Volume Relationship in the Intact Canine Left Ventricle
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Nikolić, Srdjan, Tamura, Koichi, Tamura, Takako, Yellin, Edward L., Hori, Masatsugu, editor, Suga, Hiroyuki, editor, Baan, Jan, editor, and Yellin, Edward L., editor
- Published
- 1989
- Full Text
- View/download PDF
39. Theory of Structural Properties of Covalent Semiconductors
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Yin, M. T., Chadi, James D., editor, and Harrison, Walter A., editor
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- 1985
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40. A New Look at the Glass Transition
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Aklonis, J. J., Kovacs, A. J., and Shen, Mitchel, editor
- Published
- 1979
- Full Text
- View/download PDF
41. Hybrid functional study of α-uranium
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Ravi Chinnappan, Gurpreet Kaur, and B. K. Panigrahi
- Subjects
Bulk modulus ,Condensed matter physics ,Chemistry ,Fermi level ,chemistry.chemical_element ,Thermodynamics ,Equilibrium volume ,Fraction (chemistry) ,Hartree ,Uranium ,Lower energy ,Hybrid functional ,symbols.namesake ,symbols - Abstract
We have used the hybrid density functionals to study the structural and electronic properties of alpha-U. The fraction of exact Hartree Folk exchange used is varied from 0.0 to 0.6. The equilibrium volume is found to be underestimated and bulk modulus overestimated with HSE as compared to both calculated by PBE and the experimental values. Electronic bands below the Fermi level are found to shift to lower energy with respect to PBE electronic bands which itself gives the bands shifted to lower energies as compared to UPS experiments.
- Published
- 2016
- Full Text
- View/download PDF
42. Phase decomposition and morphology characteristic in thermal aging Fe–Cr alloys under applied strain: A phase-field simulation
- Author
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Xiao-Ling Cheng, Hao Zhu, Yong-Sheng Li, and Lei Zhang
- Subjects
Nuclear and High Energy Physics ,Morphology (linguistics) ,Materials science ,Strain (chemistry) ,Alloy ,Metallurgy ,technology, industry, and agriculture ,Thermodynamics ,Thermal aging ,Equilibrium volume ,engineering.material ,Field simulation ,equipment and supplies ,Decomposition ,Nuclear Energy and Engineering ,Phase (matter) ,engineering ,General Materials Science - Abstract
The phase decomposition and morphology evolution in thermal aging Fe–Cr alloys were investigated using the phase field method. In the simulation, the effects of atomic mobility, applied strain, alloy concentration and aging temperature were studied. The simulation results show that the rate of phase decomposition is influenced by the aging temperature and the alloy concentration, the equilibrium volume fractions ( V f e ) of Cr-rich phase increases as aging temperature rises for the alloys of lower concentration, and the V f e decreases for the alloys with higher concentration. Under the applied strain, the orientation of Cr-rich phase is intensified as the aging temperature rises, and the stripe morphology is formed for the middle concentration alloys. The simulation results are helpful for understanding the phase decomposition in Fe–Cr alloys and the designing of duplex stainless steels working at high temperature.
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- 2012
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43. Effect of thickness-mediated misfit strain on the heterophase polydomain structure of epitaxial BiFeO3 films
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Jun Ouyang, Wei Zhang, and Alexander L. Roytburd
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Materials science ,Condensed matter physics ,Mechanical Engineering ,Metals and Alloys ,Equilibrium volume ,Condensed Matter Physics ,Epitaxy ,Microstructure ,Ferroelectricity ,Crystallography ,Mechanics of Materials ,Lattice (order) ,General Materials Science ,Thin film ,Misfit strain - Abstract
A heterophase polydomain structure capable of providing large electromechanical responses was recently discovered in BiFeO 3 epitaxial ferroelectric films. In this work, the energetics of such a microstructure are analyzed to predict the equilibrium volume fraction of domains at different film–substrate lattice misfits, which is a function of the substrate lattice parameters as well as the film thickness. The results from this work provide a theoretical starting point for designing and engineering elastic polydomains in BiFeO 3 thin film materials.
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- 2012
- Full Text
- View/download PDF
44. Stacking fault energy in FCC plutonium with multiple reference states in the modified embedded atom method
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Michael I. Baskes, Steven M. Valone, and Sven P. Rudin
- Subjects
Nuclear and High Energy Physics ,Electron density ,Chemistry ,Phase ordering ,chemistry.chemical_element ,Equilibrium volume ,Electronic structure ,Crystal structure ,Plutonium ,Nuclear Energy and Engineering ,Stacking-fault energy ,General Materials Science ,Atomic physics ,Monoclinic crystal system - Abstract
Basic concepts from the multi-reference state formalism for determining the functions for the modified embedded atom method (MEAM) are adopted to modeling elemental plutonium (Pu). In the case of elemental Pu, the focus is on the background electron density. Here we utilize a portion of the formalism that determines the structure of the background density necessary to capture correct phase ordering between fcc and ideal hcp crystal structures. The critical information comes from cold curves, that is the energy/volume relationships, for these phases. Practically speaking, the energy difference between these two phases determines the stacking fault energy of the material. At the same time, the simple monoclinic phase of elemental Pu also becomes higher in energy at the equilibrium volume of the fcc phase. The new model is based on first-principles electronic structure calculations and captures the basic phase ordering of those calculations.
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- 2012
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- View/download PDF
45. First-Principles Calculations of Structural Properties of NaNbO3
- Author
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R. Machado, M. G. Stachiotti, and M. Sepliarsky
- Subjects
Condensed Matter::Materials Science ,Materials science ,Volume (thermodynamics) ,Equilibrium volume ,Statistical physics ,Relative phase ,Function (mathematics) ,Total energy ,Condensed Matter Physics ,Ground state ,Stability (probability) ,Electronic, Optical and Magnetic Materials ,Solid solution - Abstract
We present ab-initio total energy calculations for different structures of NaNbO3 at different volumes using two different exchange-correlation functionals: the Perdew and Wang version of the local-density approximation (LDA) and the Wu and Cohen version of the generalized gradient approximation (GGA-WC). We found that LDA not only underestimates the equilibrium volume of the system but also predicts an incorrect ground state for this oxide. The GGA-WC functional, on the other hand, significantly improves the equilibrium volume and provides a relative phase stability in better agreement with experiments. We then use the GGA to investigate the presence of structural instabilities as a function of volume in order to provide insights for the understanding of the structural behavior of K1-xNaxNbO3 solid solutions.
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- 2012
- Full Text
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46. Phonon and thermodynamic properties of Al–Mn compounds: A first-principles study
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Yong Du, Shun Li Shang, Y. Wang, Jianjun Wang, and Zi Kui Liu
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Bulk modulus ,General Computer Science ,Condensed matter physics ,Phonon ,Chemistry ,General Physics and Astronomy ,Thermodynamics ,Equilibrium volume ,General Chemistry ,Gibbs free energy ,Bond length ,Computational Mathematics ,Generalized gradient ,symbols.namesake ,Mechanics of Materials ,symbols ,Projector augmented wave method ,General Materials Science ,Debye model - Abstract
Based on first-principles calculations within the projector augmented wave method and the generalized gradient approximation, the structural, thermodynamic as well as phonon properties of Al–Mn compounds have been investigated. The compounds studied include Al12Mn, Al6Mn, Al8Mn5, Al10Mn3, Al11Mn4 (low temperature phase), γ-AlMn, e-AlMn, and τ-AlMn. Besides phonon calculations, Debye model is also used to evaluate the thermodynamic properties at elevated temperatures, which are compared with available data from experiments and thermodynamic modeling. A good agreement is found between first-principles calculations and experimental values or CALPHAD-type calculations. For Al–Mn compounds with lower Mn content, it is observed that (i) the equilibrium volume decreases roughly linearly while the bulk modulus increases roughly linearly with increasing Mn content, (ii) the bonding strength follows the trend of Al–Al > Al–Mn (and Mn–Mn) at a fixed bond length, and (iii) roughly the higher the Mn content of Al–Mn compounds, the smaller the vibrational contribution to entropy, and in turn, to Gibbs energy. The demonstrated methodology herein, as well as the predicted thermodynamic properties, provides helpful insights into the stability of phases and thermodynamic modeling, especially for system where the experimental information is lacking or less reliable.
- Published
- 2011
- Full Text
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47. Sodium Fluoride Solubility and Crystallization in Photo-Thermo-Refractive Glass
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Larissa Glebova, Vladimir M. Fokin, Guilherme P. Souza, Edgar Dutra Zanotto, Leonid B. Glebov, and Julien Lumeau
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Supersaturation ,Materials science ,Analytical chemistry ,Mineralogy ,Equilibrium volume ,law.invention ,chemistry.chemical_compound ,chemistry ,law ,Phase (matter) ,Thermal ,Sodium fluoride ,Materials Chemistry ,Ceramics and Composites ,Solubility ,Crystallization ,Refractive index - Abstract
Photo-thermo-refractive (PTR) glass undergoes a refractive index change after UV exposure followed by heat treatment for nanocrystallization of NaF, allowing phase holograms to be permanently recorded in the glass. PTR glass was invented 60 years ago, and optical elements based on PTR glass have been produced for the past decade, but its detailed crystallization mechanism is largely unknown. Since solubility and composition of the parent glass determine the supersaturation and hence the thermodynamic driving force for crystallization, the present paper was aimed at measuring the solubility of NaF in PTR glass via estimating the equilibrium volume fraction of crystallized NaF as a function of temperature. The temperature above which all NaF originally contained in the parent glass remains dissolved in the melt, and that below which all NaF could crystallize, were also estimated. Redesigning of thermal processing parameters and composition of PTR glass, aiming at the improvement of optical elements based on this glass, can be performed in light of the results achieved.
- Published
- 2010
- Full Text
- View/download PDF
48. Electronic structure of RTAl (R=Y, Lu; T=Ni, Cu and Pd) compounds
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Martin Diviš and Pavel Javorský
- Subjects
Materials science ,Condensed matter physics ,Intermetallic ,Physical chemistry ,Equilibrium volume ,Electronic density of states ,Electronic structure ,Electrical and Electronic Engineering ,Condensed Matter Physics ,Electronic band structure ,Electronic, Optical and Magnetic Materials - Abstract
First-principles calculations based on density-functional theory were performed for the first time on RTAl (R=Y, Lu, T=Ni, Cu, Pd) compounds. The electronic density of states and equilibrium volume were studied using the relativistic full-potential APW plus local-orbitals calculations and compared with the experimental data available.
- Published
- 2010
- Full Text
- View/download PDF
49. Ab initiocalculations of the wolframite MnWO4under high pressure
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S. López-Moreno, Alessandra Romero, Alfonso Muñoz, and Plácida Rodríguez-Hernández
- Subjects
Wolframite ,Equation of state ,Chemistry ,Ab initio ,Thermodynamics ,Equilibrium volume ,engineering.material ,Condensed Matter Physics ,Condensed Matter::Materials Science ,Ferromagnetism ,Ab initio quantum chemistry methods ,High pressure ,engineering ,Physical chemistry ,Condensed Matter::Strongly Correlated Electrons ,Density functional theory - Abstract
Ab initio calculations, based on the density functional theory, of the structural properties of MnWO4 wolframite compound are reported. We obtain the equilibrium volume from an equation of state with the anti-ferromagnetic (AF) and ferromagnetic configurations, AF being the lowest energy state, and the structural properties of the wolframite structure at zero pressure are obtained. We also study the wolframite structure up to a pressure of 31 GPa, and the pressure evolution of structural parameters is found to be in good agreement with the available experimental data.
- Published
- 2009
- Full Text
- View/download PDF
50. Thermal and physical properties of Al–Ni–Ru–M alloys
- Author
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H.O. Mosca, M.F. del Grosso, and Guillermo Bozzolo
- Subjects
Materials science ,Mechanical Engineering ,Metallurgy ,Analytical chemistry ,chemistry.chemical_element ,Equilibrium volume ,Condensed Matter Physics ,Thermal expansion ,Ruthenium ,Nickel ,chemistry ,Mechanics of Materials ,Aluminium ,Phase (matter) ,Thermal ,Compressibility ,General Materials Science - Abstract
The equilibrium volume, compressibility, and coefficient of thermal expansion of B2-based Al–Ni–Ru–M alloys (M = B, Si, Ti, Sc, V, Cr, Mn, Fe, Co, Cu, Zn, Nb, Mo, Tc, Rh, Pd, Zr, Ag, Ta, Hf, W, Re, Os, Ir, Pt, and Au) are determined as a function of concentration of the additive M. Details of the phase structure and determination of these properties are obtained from large-scale simulated annealing of the quaternary alloys using the Bozzolo–Ferrante–Smith method for alloys for the calculation of the energy.
- Published
- 2009
- Full Text
- View/download PDF
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