Journal articles on the topic 'Solids - Diverse Thermodynamics Properties'
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Hofmeister, Anne M. "Dependence of Heat Transport in Solids on Length-Scale, Pressure, and Temperature: Implications for Mechanisms and Thermodynamics." Materials 14, no. 2 (January 18, 2021): 449. http://dx.doi.org/10.3390/ma14020449.
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Accurate laser-flash measurements of thermal diffusivity (D) of diverse bulk solids at moderate temperature (T), with thickness L of ~0.03 to 10 mm, reveal that D(T) = D∞(T)[1 − exp(−bL)]. When L is several mm, D∞(T) = FT−G + HT, where F is constant, G is ~1 or 0, and H (for insulators) is ~0.001. The attenuation parameter b = 6.19D∞−0.477 at 298 K for electrical insulators, elements, and alloys. Dimensional analysis confirms that D → 0 as L → 0, which is consistent with heat diffusion, requiring a medium. Thermal conductivity (κ) behaves similarly, being proportional to D. Attenuation describing heat conduction signifies that light is the diffusing entity in solids. A radiative transfer model with 1 free parameter that represents a simplified absorption coefficient describes the complex form for κ(T) of solids, including its strong peak at cryogenic temperatures. Three parameters describe κ with a secondary peak and/or a high-T increase. The strong length dependence and experimental difficulties in diamond anvil studies have yielded problematic transport properties. Reliable low-pressure data on diverse thick samples reveal a new thermodynamic formula for specific heat (∂ln(cP)/∂P = −linear compressibility), which leads to ∂ln(κ)/∂P = linear compressibility + ∂lnα/∂P, where α is thermal expansivity. These formulae support that heat conduction in solids equals diffusion of light down the thermal gradient, since changing P alters the space occupied by matter, but not by light.
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Sarazen, Michele L., and Enrique Iglesia. "Stability of bound species during alkene reactions on solid acids." Proceedings of the National Academy of Sciences 114, no. 20 (May 1, 2017): E3900—E3908. http://dx.doi.org/10.1073/pnas.1619557114.
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This study reports the thermodynamics of bound species derived from ethene, propene, n-butene, and isobutene on solid acids with diverse strength and confining voids. Density functional theory (DFT) and kinetic data indicate that covalently bound alkoxides form C–C bonds in the kinetically relevant step for dimerization turnovers on protons within TON (0.57 nm) and MOR (0.67 nm) zeolitic channels and on stronger acids HPW (polyoxometalate clusters on silica). Turnover rates for mixed alkenes give relative alkoxide stabilities; the respective adsorption constants are obtained from in situ infrared spectra. Tertiary alkoxides (from isobutene) within larger voids (MOR, HPW) are more stable than less substituted isomers but are destabilized within smaller concave environments (TON) because framework distortions are required to avoid steric repulsion. Adsorption constants are similar on MOR and HPW for each alkoxide, indicating that binding is insensitive to acid strength for covalently bound species. DFT-derived formation free energies for alkoxides with different framework attachments and backbone length/structure agree with measurements when dispersion forces, which mediate stabilization by confinement in host–guest systems, are considered. Theory reveals previously unrecognized framework distortions that balance the C–O bond lengths required for covalency with host–guest distances that maximize van der Waals contacts. These distortions, reported here as changes in O-atom locations and dihedral angles, become stronger for larger, more substituted alkoxides. The thermodynamic properties reported here for alkoxides and acid hosts differing in size and conjugate-anion stability are benchmarked against DFT-derived free energies; their details are essential to design host–guest pairs that direct alkoxide species toward specific products.
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Grau Turuelo, Constantino, Sebastian Pinnau, and Cornelia Breitkopf. "Estimating a Stoichiometric Solid’s Gibbs Free Energy Model by Means of a Constrained Evolutionary Strategy." Materials 14, no. 2 (January 19, 2021): 471. http://dx.doi.org/10.3390/ma14020471.
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Modeling of thermodynamic properties, like heat capacities for stoichiometric solids, includes the treatment of different sources of data which may be inconsistent and diverse. In this work, an approach based on the covariance matrix adaptation evolution strategy (CMA-ES) is proposed and described as an alternative method for data treatment and fitting with the support of data source dependent weight factors and physical constraints. This is applied to a Gibb’s Free Energy stoichiometric model for different magnesium sulfate hydrates by means of the NASA9 polynomial. Its behavior is proved by: (i) The comparison of the model to other standard methods for different heat capacity data, yielding a more plausible curve at high temperature ranges; (ii) the comparison of the fitted heat capacity values of MgSO4·7H2O against DSC measurements, resulting in a mean relative error of a 0.7% and a normalized root mean square deviation of 1.1%; and (iii) comparing the Van’t Hoff and proposed Stoichiometric model vapor-solid equilibrium curves to different literature data for MgSO4·7H2O, MgSO4·6H2O, and MgSO4·1H2O, resulting in similar equilibrium values, especially for MgSO4·7H2O and MgSO4·6H2O. The results show good agreement with the employed data and confirm this method as a viable alternative for fitting complex physically constrained data sets, while being a potential approach for automatic data fitting of substance data.
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Glasser, Leslie, and H. Donald Brooke Jenkins. "Predictive thermodynamics for ionic solids and liquids." Physical Chemistry Chemical Physics 18, no. 31 (2016): 21226–40. http://dx.doi.org/10.1039/c6cp00235h.
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ZARDAS, G. E., and CH I. SYMEONIDES. "TEMPERATURE DEPENDENT MONOVACANCY PARAMETERS VERSUS DIVACANCIES IN ANALYZING DATA OF DEFECTS IN METALS." Modern Physics Letters B 23, no. 18 (July 20, 2009): 2235–41. http://dx.doi.org/10.1142/s0217984909020369.
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The appropriate procedure for analyzing experimental data of defects in metals is discussed. The following two diverse procedures have been proposed earlier: either in terms of single vacancy formation with temperature dependent enthalpy and entropy, or by assuming coexistence of vacancies and divacancies with temperature-independent parameters. Using aspects of thermodynamics of the defect formation processes in solids, we show that the former procedure leads to self-consistent parameters.
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ZMYWACZYK, Janusz. "Thermal Properties of Solids – Theoretical Basis, Research Methods and Selected Results of Proprietary Research." Problems of Mechatronics Armament Aviation Safety Engineering 12, no. 2 (June 30, 2021): 9–38. http://dx.doi.org/10.5604/01.3001.0014.9331.
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This paper refers to an inaugural lecture prepared by the author for the inauguration of the New Academic Year 2020/2021 at the Faculty of Mechatronics, Armament and Aerospace of Military University of Technology (MUT) in Warsaw (Poland) on 2 October 2020. It presents the origins of research into thermal properties of solids since the mid-1970s by the employees of the thermodynamic research unit at the Department of Aerodynamics and Thermodynamics, followed by the basic modalities of heat transfer, theoretical foundations of thermal expansion, specific heat, thermal conductivity and thermal diffusivity of solids. The measuring apparatus created as a result of proprietary research studies and purchased from market-leading manufacturers is shown with a selection of results from the research into the thermal properties of solids, which are largely the outcome of the application our own research procedures.
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Varotsos, Panayiotis A., Nicholas V. Sarlis, and Efthimios S. Skordas. "Thermodynamics of Point Defects in Solids and Relation with the Bulk Properties: Recent Results." Crystals 12, no. 5 (May 11, 2022): 686. http://dx.doi.org/10.3390/cryst12050686.
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For several decades, the crucial question has arisen as to whether there exists any direct interconnection between the thermodynamic parameters of point defects in solids with the bulk properties of the solid under investigation. To answer this important question, an interrelation of the defect Gibbs energy gi in solids with bulk properties has been proposed almost half a century ago. Considering that gi corresponds to an isobaric and isothermal process, this interrelation states that, for different processes (defect formation, self-diffusion activation, and heterodiffusion), gi is proportional to the isothermal bulk modulus B and the mean volume per atom Ω, termed cBΩ model. Here, we review several challenging applications of this interrelation that appeared during the last decade (2011–2021), including high pressure diamond anvil measurements, high Tc superconductors, nuclear fuels, and materials for micro-electronics devices, applications of usefulness in Geophysics and Seismology, a problem of major technological interest, search for compositions of better target properties in Cu-Co-Si alloys via machine learning as well as two independent studies on the physical origin of this interrelation that has been further strengthened during the last few years.
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Burns, S. J., J. Ryan Rygg, Danae Polsin, Brian Henderson, Michelle Marshall, Shuai Zhang, Suxing Hu, and Gilbert Collins. "Planar, longitudinal, compressive waves in solids: Thermodynamics and uniaxial strain restrictions." Journal of Applied Physics 131, no. 21 (June 7, 2022): 215904. http://dx.doi.org/10.1063/5.0097342.
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A new tri-axial pressure-based constitutive expression has been found using Cauchy's stress tensor. This stress state emphasizes pressure and shear stress. The description is a pressure plus an effective shear stress allowing for a constitutive law based on atomic solid-state phase changes in crystalline cells due to pressure plus shear-based dislocation motion commonly associated with plasticity. Pressure has a new role in the material's constitutive response as it is separated from plasticity. The thermo-mechanical system describes third-order Gibbs’ expressions without specific volume restrictions placed upon the material. Isothermally, the ratio of heat to shear work in elastic copper is shown to approach zero at a very low temperature and become larger than one as temperature approaches melting. Wave compression models investigated are elastic and plastic: in fully elastic materials, the planar wave is restricted by Poisson's effect although plastic shear changes this constraint. Plastic deformation, dominated by dissipative shear stresses in uniaxial strain, heats the material while excluding phase changes from hydrostatic pressures. The material properties per se across Hugoniot shocks are described with entropy concepts. Shock waves are exceedingly complex since the constitutive laws are linked at extreme temperatures, pressures, and shear stresses. Isothermal, isentropic, isochoric, and iso-shear conditions are used throughout with Jacobian algebra.
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Burns, S. J., J. Ryan Rygg, Danae Polsin, Brian Henderson, Michelle Marshall, Shuai Zhang, Suxing Hu, and Gilbert Collins. "Planar, longitudinal, compressive waves in solids: Thermodynamics and uniaxial strain restrictions." Journal of Applied Physics 131, no. 21 (June 7, 2022): 215904. http://dx.doi.org/10.1063/5.0097342.
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A new tri-axial pressure-based constitutive expression has been found using Cauchy's stress tensor. This stress state emphasizes pressure and shear stress. The description is a pressure plus an effective shear stress allowing for a constitutive law based on atomic solid-state phase changes in crystalline cells due to pressure plus shear-based dislocation motion commonly associated with plasticity. Pressure has a new role in the material's constitutive response as it is separated from plasticity. The thermo-mechanical system describes third-order Gibbs’ expressions without specific volume restrictions placed upon the material. Isothermally, the ratio of heat to shear work in elastic copper is shown to approach zero at a very low temperature and become larger than one as temperature approaches melting. Wave compression models investigated are elastic and plastic: in fully elastic materials, the planar wave is restricted by Poisson's effect although plastic shear changes this constraint. Plastic deformation, dominated by dissipative shear stresses in uniaxial strain, heats the material while excluding phase changes from hydrostatic pressures. The material properties per se across Hugoniot shocks are described with entropy concepts. Shock waves are exceedingly complex since the constitutive laws are linked at extreme temperatures, pressures, and shear stresses. Isothermal, isentropic, isochoric, and iso-shear conditions are used throughout with Jacobian algebra.
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Awaga, Kunio, Yoshikatsu Umezono, Wataru Fujita, Hirofumi Yoshikawa, HengBo Cui, Hayao Kobayashi, Sarah S. Staniland, and Neil Robertson. "Diverse magnetic and electrical properties of molecular solids containing the thiazyl radical BDTA." Inorganica Chimica Acta 361, no. 14-15 (October 2008): 3761–70. http://dx.doi.org/10.1016/j.ica.2008.03.065.
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Mai, Xuan-Dung, Yen Thi Hai Phan, and Van-Quang Nguyen. "Excitation-Independent Emission of Carbon Quantum Dot Solids." Advances in Materials Science and Engineering 2020 (December 10, 2020): 1–5. http://dx.doi.org/10.1155/2020/9643168.
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Solid assemblies of carbon quantum dots (CQDs) are important for diverse applications including LEDs, solar cells, and photosensors; their optical and electrical properties have not been explored yet. Herein, we used amphiphilic CQDs synthesized from citric acid and thiourea by a solvothermal method to fabricate CQD solid films. Optical properties of CQDs studied by UV-Vis and photoluminescence spectroscopies indicate that CQDs possess three different emission centers at 425 nm, 525 nm, and 625 nm originating from C sp2 states, N-states, and S-states, respectively. In a solid state, π-π stacking quenched the blue emission, while the red emission increased. Importantly, CQD films exhibited excitation independence, which is important to design solid-state lighting applications.
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Hoffman, Alexander E. J., Jelle Wieme, Sven M. J. Rogge, Louis Vanduyfhuys, and Veronique Van Speybroeck. "The impact of lattice vibrations on the macroscopic breathing behavior of MIL-53(Al)." Zeitschrift für Kristallographie - Crystalline Materials 234, no. 7-8 (July 26, 2019): 529–45. http://dx.doi.org/10.1515/zkri-2018-2154.
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Abstract The mechanism inducing the breathing in flexible metal-organic frameworks, such as MIL-53(Al), is still not fully understood. Herein, the influence of lattice vibrations on the breathing transition in MIL-53(Al) is investigated to gain insight in this phenomenon. Through solid-state density-functional theory calculations, the volume-dependent IR spectrum is computed together with the volume-frequency relations of all vibrational modes. Furthermore, important thermodynamic properties such as the Helmholtz free energy, the specific heat capacity, the bulk modulus, and the volumetric thermal expansion coefficient are derived via these volume-frequency relations using the quasi-harmonic approximation. The simulations expose a general volume-dependency of the vibrations with wavenumbers above 300 cm−1 due to their localized nature. In contrast, a diverse set of volume-frequency relations are observed for vibrations in the terahertz region (<300 cm−1) containing the vibrations exhibiting collective behavior. Some terahertz vibrations display large frequency differences over the computed volume range, induced by either repulsion or strain effects, potentially triggering the phase transformation. Finally, the impact of the lattice vibrations on the thermodynamic properties is investigated. This reveals that the closed pore to large pore phase transformation in MIL-53(Al) is mainly facilitated by terahertz vibrations inducing rotations of the organic linker, while the large pore to closed pore phase transformation relies on two framework-specific soft modes.
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Ruiz, Antonio Guerrero, and Inmaculada Rodríguez-Ramos. "Application of New Nanoparticle Structures as Catalysts." Nanomaterials 10, no. 9 (August 27, 2020): 1686. http://dx.doi.org/10.3390/nano10091686.
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Nanocatalysts, more precisely solids nanomaterials with catalytic properties to be used as heterogeneous catalysts, are an extended and very diverse group of nanostructured materials representing, at present, an active area of research with application in many catalyzed processes [...]
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Poon, Louis, Jacob R. Hum, and Richard G. Weiss. "Neat Linear Polysiloxane-Based Ionic Polymers: Insights into Structure-Based Property Modifications and Applications." Macromol 1, no. 1 (December 21, 2020): 2–17. http://dx.doi.org/10.3390/macromol1010002.
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A diverse range of linear polysiloxane-based ionic polymers that are hydrophobic and highly flexible can be obtained by substituting the polymers with varying amounts of ionic centers. The materials can be highly crystalline solids, amorphous soft solids, poly(ionic) liquids or viscous polymer liquids. A key to understanding how structural variations can lead to these different materials is the establishment of correlations between the physical (dynamic and static) properties and the structures of the polymers at different distance scales. This short review provides such correlations by examining the influence of structural properties (such as molecular weights, ion pair contents, and ion types) on key bulk properties of the materials.
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Yu, Xinting, Yue Yu, Julia Garver, Jialin Li, Abigale Hawthorn, Ella Sciamma-O’Brien, Xi Zhang, and Erika Barth. "Material Properties of Organic Liquids, Ices, and Hazes on Titan." Astrophysical Journal Supplement Series 266, no. 2 (June 1, 2023): 30. http://dx.doi.org/10.3847/1538-4365/acc6cf.
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Abstract Titan has a diverse range of materials in its atmosphere and on its surface: the simple organics that reside in various phases (gas, liquid, and ice) and the solid complex refractory organics that form Titan’s haze layers. These materials all actively participate in various physical processes on Titan, and many material properties are found to be important in shaping these processes. Future in situ explorations on Titan would likely encounter a range of materials, and a comprehensive database to archive the material properties of all possible material candidates will be needed. Here, we summarize several important material properties of the organic liquids, ices, and the refractory hazes on Titan that are available in the literature and/or that we have computed. These properties include thermodynamic properties (phase-change points, sublimation and vaporization saturation vapor pressure, and latent heat), and physical properties (organic liquid densities and organic ice and haze densities). We have developed a new database to provide a repository for these data and make them available to the science community. These data can be used as inputs for various theoretical models to interpret current and future remote sensing and in situ atmospheric and surface measurements on Titan. The material properties of the simple organics may also be applicable to giant planets and icy bodies in the outer solar system, interstellar medium, protoplanetary disks, and exoplanets.
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Stoneham, A. M. "Theory of Solid-State Defects." MRS Bulletin 16, no. 12 (December 1991): 22–26. http://dx.doi.org/10.1557/s0883769400055305.
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Serious studies of materials are often serious studies of defects, for control of properties of materials implies control of defects or impurities. Understanding defect phenomena is crucial, and both theoretical ideas and modeling are enhancing key areas of materials properties and processing. I shall review some of the ways theory contributes. Theory enters into all aspects of materials science, even if you don't always realize you are using it.Even self-styled practical people, for whom theory is a luxury, use theory routinely in its first main role, as a framework for the data they lovingly collect. Elasticity theory, electromagnetic theory, and thermodynamics are normal tools for working engineers. The simplest ideas about electronic and atomic structures of solids are now so standard that one can forget their original impact, just as one forgets those within living memory who objected even to the idea of atoms. It was theory which gave clear guidelines for solids to be metals or insulators, when the real-space ideas of crystal structures based on interacting atoms were complemented by the reciprocal space notions from band theory. Such rules had been far from obvious. The behavior of amorphous solids has forced analogous theory-led upheavals in understanding.
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Safonov, O. G., L. Bindi, and V. L. Vinograd. "Potassium-bearing clinopyroxene: a review of experimental, crystal chemical and thermodynamic data with petrological applications." Mineralogical Magazine 75, no. 4 (August 2011): 2467–84. http://dx.doi.org/10.1180/minmag.2011.075.4.2467.
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AbstractAvailable experimental data on chemical composition and crystal structure of K-bearing clinopyroxenes are compiled together with the results of atomistic simulations and thermodynamic calculations of mineral equilibria. It is shown that the limited solubility of K2O in clinopyroxene from crustal rocks cannot be ascribed to the strong non-ideality of mixing between diopside (CaMgSi2O6) and K-jadeite (KAlSi2O6) components. The more likely reason is the instability of the potassic endmember with respect to other K-bearing phases. As the volume effects of typical K-jadeite-forming reactions are negative, the incorporation of K in the clinopyroxene structure becomes less difficult at higher pressure. Atomistic simulations predict that the thermodynamic mixing properties of diopside-K-jadeite solid-solutions at high temperature approach those of a regular mixture with a relatively small positive excess enthalpy. The standard enthalpy of formation (ΔfH° = —2932.7 kJ/mol), the standard volume (V° = 6.479 J mol–1 bar–1) and the isothermal bulk modulus (K0 = 145 GPa) of K-jadeite were calculated from first principles, and the standard entropy (S° = 141.24 J mol–1 K–1) and thermal-expansion coefficient (α = 3.3 x 1CP–5 K–1) of the K-jadeite endmember were estimated using quasi-harmonic lattice-dynamic calculations based on a force-field model. The estimated thermodynamic data are used to compute compositions of K-bearing clinopyroxenes in diverse mineral assemblages within a wide P-T interval. The review substantiates the conclusion that clinopyroxene can serve as an effective container for K at upper-mantle conditions.
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Terehov S. V. "Thermal properties of matter within the model of a two-phase system." Physics of the Solid State 64, no. 8 (2022): 1089. http://dx.doi.org/10.21883/pss.2022.08.54631.352.
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It has been established that the relations of the two-phase system model are applicable for describing the thermal properties of solids with disordered and crystalline structures. It is shown that the model adequately describes the curves of isochronous and isothermal crys-tallization of amorphous alloys and thermal changes in the volume of their samples. It is also suitable for calculating the heat capacities and thermal expansion coefficients of sub-stances that are diverse in their physical nature. Keywords: two-phase system, thermal expansion coefficient, heat capacity, amorphous alloys, com-plex oxides.
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Singh, Madan, Benedict Molibeli Taele, and Ghanshyam Patel. "Effect of Shape and Size on Curie Temperature, Debye Frequency, Melting Entropy and Enthalpy of Nanosolids." Oriental Journal of Chemistry 34, no. 5 (October 18, 2018): 2282–91. http://dx.doi.org/10.13005/ojc/340508.
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The shape and size dependent melting thermodynamics of metallic nanoparticles are predicted by application of bond theory model, free of any adjustable parameter. Thermodynamic properties like Debye frequency, Curie temperature, melting entropy and enthalpy of Al, Sn, In, Cu, β-Fe and Fe3O4 for spherical and non spherical shapes nanoparticles with different size have been studied. In this model, the effects of relaxation factor for the low dimension solids are considered. The depression in Debye frequency, Curie temperature, melting entropy and enthalpy is predicted. The model predictions are supported by the available experimental and simulation results.
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Vidali, Gianfranco. "DIVISION XII / COMMISSION 14 / WORKING GROUP SOLIDS AND THEIR SURFACES." Proceedings of the International Astronomical Union 4, T27A (December 2008): 400–414. http://dx.doi.org/10.1017/s1743921308025969.
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In the last decade there has been a tremendous increase of interest in studying processes occurring on IS dust. In part this is due to the availability of ground-based and space-borne high quality instruments which have been used to detect molecules in diverse astrophysical environments, from protoplanetary disks to hot cores and dense clouds. It has also been recognized that IS dust has an important role in the formation of molecules, from molecular hydrogen to methanol. Therefore, it is necessary not to study only properties of dust, but also understand how atoms and molecules interact with and on dust.
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Choi, Jeong Ho, and Jung Hwan Lee. "Preliminary Research of Truss-Wall Corrugated Cellular Solids." Applied Mechanics and Materials 510 (February 2014): 139–49. http://dx.doi.org/10.4028/www.scientific.net/amm.510.139.
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The objective of this study is to find the density, stiffness, and strength of truss-wall unit cell models. The diamond-corrugation, triangular-corrugation, and Navtruss-corrugation models are used for the unit cell. The ideal solutions derived for these are based on truss-wall unit cell models and are developed using the GibsonAshby theory. To verify the ideal solutions of the models, the density, strength, and stiffness are simulated using ABAQUS software and compared with the ideal solutions on a log-log scale. The material properties of stainless steel 304 are applied. The diameter is 0.5 mm; the opening width is 0.5 mm; and the corrugation angle is 45°. Consequently, the relative Youngs modulus and relative yield strength of the truss-wall unit models are good matches for the ideal expectations. It may be possible to apply a truss-wall model to diverse fields such as transportation or biomedical applications as one of the open-cell cellular solids.
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Fries, Kai S., and Simon Steinberg. "Exploring the Interdependence between Electronically Unfavorable Situations and Pressure in a Chalcogenide Superconductor." Inorganics 11, no. 2 (January 27, 2023): 61. http://dx.doi.org/10.3390/inorganics11020061.
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The development of solids with the requested chemical and physical properties requires a thorough understanding of their electronic structures, as proper knowledge of the electronic structure of a given solid provides invaluable information regarding its properties. In this context, recent research on two competing sorts of electronic instabilities in chalcogenide superconductors stimulated us to explore the interdependence between these instabilities and another aspect, pressure, which was previously shown to influence the presence of a superconducting state in diverse solids. To accomplish our goal, we carried out pressure-dependent examinations of the electronic structures of two tellurides, YTe and YTe0.97, which were inspected as prototypes in our explorations based on quantum-chemical means. In addition to our pressure-dependent explorations of the electronic structures, we also performed chemical bonding analyses to reveal the subtle interplay between pressure and two sorts of electronically unfavorable situations.
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Haghighi, Ehsan Motevali, and Seonhong Na. "A Multifeatured Data-Driven Homogenization for Heterogeneous Elastic Solids." Applied Sciences 11, no. 19 (October 3, 2021): 9208. http://dx.doi.org/10.3390/app11199208.
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A computational homogenization of heterogeneous solids is presented based on the data-driven approach for both linear and nonlinear elastic responses. Within the Double-Scale Finite Element Method (FE2) framework, a data-driven model is proposed to substitute the micro-level Finite Element (FE) simulations to reduce computational costs in multiscale simulations. The heterogeneity of porous solids at the micro-level is considered in various material properties and geometrical attributes. For material properties, elastic constants, which are Lame’s coefficients, are subjected to be heterogeneous in the linear elastic responses. For geometrical features, different numbers, sizes, and locations of voids are considered to reflect the heterogeneity of porous solids. A database for homogenized microstructural responses is constructed from a series of micro-level FE simulations, and machine learning is used to train and test our proposed model. In particular, four geometrical descriptors are designed, based on N-probability and lineal-path functions, to clearly reflect the geometrical heterogeneity of various microstructures. This study indicates that a simple deep neural networks model can capture diverse microstructural heterogeneous responses well when given proper input sources, including the geometrical descriptors, are considered to establish a computational data-driven homogenization scheme.
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Ulrich, Anne S. "Biophysical Aspects of Using Liposomes as Delivery Vehicles." Bioscience Reports 22, no. 2 (April 1, 2002): 129–50. http://dx.doi.org/10.1023/a:1020178304031.
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Liposomes are used as biocompatible carriers of drugs, peptides, proteins, plasmic DNA, antisense oligonucleotides or ribozymes, for pharmaceutical, cosmetic, and biochemical purposes. The enormous versatility in particle size and in the physical parameters of the lipids affords an attractive potential for constructing tailor-made vehicles for a wide range of applications. Some of the recent literature will be reviewed here and presented from a biophysical point of view, thus providing a background for the more specialized articles in this special issue on liposome technology. Different properties (size, colloidal behavior, phase transitions, and polymorphism) of diverse lipid formulations (liposomes, lipoplexes, cubic phases, emulsions, and solid lipid nanoparticles) for distinct applications (parenteral, transdermal, pulmonary, and oral administration) will be rationalized in terms of common structural, thermodynamic and kinetic parameters of the lipids. This general biophysical basis helps to understand pharmaceutically relevant aspects such as liposome stability during storage and towards serum, the biodistribution and specific targeting of cargo, and how to trigger drug release and membrane fusion. Methods for the preparation and characterization of liposomal formulations in vitro will be outlined, too.
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Bonilla, Steve L., Sarah K. Denny, John H. Shin, Aurora Alvarez-Buylla, William J. Greenleaf, and Daniel Herschlag. "High-throughput dissection of the thermodynamic and conformational properties of a ubiquitous class of RNA tertiary contact motifs." Proceedings of the National Academy of Sciences 118, no. 33 (August 9, 2021): e2109085118. http://dx.doi.org/10.1073/pnas.2109085118.
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Despite RNA’s diverse secondary and tertiary structures and its complex conformational changes, nature utilizes a limited set of structural “motifs”—helices, junctions, and tertiary contact modules—to build diverse functional RNAs. Thus, in-depth descriptions of a relatively small universe of RNA motifs may lead to predictive models of RNA tertiary conformational landscapes. Motifs may have different properties depending on sequence and secondary structure, giving rise to subclasses that expand the universe of RNA building blocks. Yet we know very little about motif subclasses, given the challenges in mapping conformational properties in high throughput. Previously, we used “RNA on a massively parallel array” (RNA-MaP), a quantitative, high-throughput technique, to study thousands of helices and two-way junctions. Here, we adapt RNA-MaP to study the thermodynamic and conformational properties of tetraloop/tetraloop receptor (TL/TLR) tertiary contact motifs, analyzing 1,493 TLR sequences from different classes. Clustering analyses revealed variability in TL specificity, stability, and conformational behavior. Nevertheless, natural GAAA/11ntR TL/TLRs, while varying in tertiary stability by ∼2.5 kcal/mol, exhibited conserved TL specificity and conformational properties. Thus, RNAs may tune stability without altering the overall structure of these TL/TLRs. Furthermore, their stability correlated with natural frequency, suggesting thermodynamics as the dominant selection pressure. In contrast, other TL/TLRs displayed heterogenous conformational behavior and appear to not be under strong thermodynamic selection. Our results build toward a generalizable model of RNA-folding thermodynamics based on the properties of isolated motifs, and our characterized TL/TLR library can be used to engineer RNAs with predictable thermodynamic and conformational behavior.
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D’Vries, Richard F., Germán E. Gomez, and Javier Ellena. "Highlighting Recent Crystalline Engineering Aspects of Luminescent Coordination Polymers Based on F-Elements and Ditopic Aliphatic Ligands." Molecules 27, no. 12 (June 14, 2022): 3830. http://dx.doi.org/10.3390/molecules27123830.
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Three principal factors may influence the final structure of coordination polymers (CPs): (i) the nature of the ligand, (ii) the type and coordination number of the metal center, and (iii) the reaction conditions. Further, flexible carboxylate aliphatic ligands have been widely employed as building blocks for designing and synthesizing CPs, resulting in a diverse array of materials with exciting architectures, porosities, dimensionalities, and topologies as well as an increasing number of properties and applications. These ligands show different structural features, such as torsion angles, carbon backbone number, and coordination modes, which affect the desired products and so enable the generation of polymorphs or crystalline phases. Additionally, due to their large coordination numbers, using 4f and 5f metals as coordination centers combined with aliphatic ligands increases the possibility of obtaining different crystal phases. Additionally, by varying the synthetic conditions, we may control the production of a specific solid phase by understanding the thermodynamic and kinetic factors that influence the self-assembly process. This revision highlights the relationship between the structural variety of CPs based on flexible carboxylate aliphatic ligands and f-elements (lanthanide and actinides) and their outstanding luminescent properties such as solid-state emissions, sensing, and photocatalysis. In this sense, we present a structural analysis of the CPs reported with the oxalate ligand, as the one rigid ligand of the family, and other flexible dicarboxylate linkers with –CH2– spacers. Additionally, the nature of the luminescence properties of the 4f or 5f-CPs is analyzed, and finally, we present a novel set of CPs using a glutarate-derived ligand and samarium, with the formula [2,2′-bipyH][Sm(HFG)2 (2,2′-bipy) (H2O)2]•(2,2′-bipy) (α-Sm) and [2,2′-bipyH][Sm(HFG)2 (2,2′-bipy) (H2O)2] (β-Sm).
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Saha, Saumitra, and Udo Becker. "A first principles study of energetics and electronic structural responses of uranium-based coordination polymers to Np incorporation." Radiochimica Acta 106, no. 1 (January 26, 2018): 1–13. http://dx.doi.org/10.1515/ract-2016-2732.
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AbstractRecently developed coordination polymers (CPs) and metal organic frameworks (MOFs) may find applications in areas such as catalysis, hydrogen storage, and heavy metal immobilization. Research on the potential application of actinide-based CPs (An-CP/MOFs) is not as advanced as transition metal-based MOFs. In order to modify their structures necessary for optimizing thermodynamic and electronic properties, here, we described how a specific topology of a particular actinide-based CP or MOF responds to the incorporation of other actinides considering their diverse coordination chemistry associated with the multiple valence states and charge-balancing mechanisms. In this study, we apply a recently developed DFT-based method to determine the relative stability of transuranium incorporated CPs in comparison to their uranium counterpart considering both solid and aqueous state sources and sinks to understand the mechanism and energetics of charge-balanced Np5+incorporation into three uranium-based CPs. The calculated Np5++H+incorporation energies for these CPs range from 0.33 to 0.52 eV, depending on the organic linker, when using the solid oxide Np source Np2O5and U sink UO3. Incorporation energies of these CPs using aqueous sources and sinks increase to 2.85–3.14 eV. The thermodynamic and structural analysis in this study aides in determining, why certain MOF topologies and ligands are selective for some actinides and not for others. This means that once this method is extended across a variety of CPs with their respective linker molecules and different actinides, it can be used to identify certain CPs with certain organic ligands being specific for certain actinides. This information can be used to construct CPs for actinide separation. This is the first determination of the electronic structure (band structure, density of states) of these uranium- and transuranium-based CPs which may eventually lead to design CPs with certain optical or catalytic properties. While the reduction of the DFT-determined-bandgap goes from 3.1 eV to 2.4 eV when going from CP1 to CP3, showing the influence of the linker, Np6+incorporation reduces the bandgap for CP1 and CP3, while increasing it for CP2. The coupled substitution of U6+→Np5++H+reduces the bandgap significantly, but only for CP3.
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Edueng, Bergström, Gråsjö, and Mahlin. "Long-Term Physical (In)Stability of Spray-Dried Amorphous Drugs: Relationship with Glass-Forming Ability and Physicochemical Properties." Pharmaceutics 11, no. 9 (August 21, 2019): 425. http://dx.doi.org/10.3390/pharmaceutics11090425.
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This study shows the importance of the chosen method for assessing the glass-forming ability (GFA) and glass stability (GS) of a drug compound. Traditionally, GFA and GS are established using in situ melt-quenching in a differential scanning calorimeter. In this study, we included 26 structurally diverse glass-forming drugs (i) to compare the GFA class when the model drugs were produced by spray-drying with that when melt-quenching was used, (ii) to investigate the long-term physical stability of the resulting amorphous solids, and (iii) to investigate the relationship between physicochemical properties and the GFA of spray-dried solids and their long-term physical stability. The spray-dried solids were exposed to dry (<5% RH) and humid (75% RH) conditions for six months at 25 °C. The crystallization of the spray-dried solids under these conditions was monitored using a combination of solid-state characterization techniques including differential scanning calorimetry, Raman spectroscopy, and powder X-ray diffraction. The GFA/GS class assignment for 85% of the model compounds was method-dependent, with significant differences between spray-drying and melt-quenching methods. The long-term physical stability under dry condition of the compounds was predictable from GFA/GS classification and glass transition and crystallization temperatures. However, the stability upon storage at 75% RH could not be predicted from the same data. There was no strong correlation between the physicochemical properties explored and the GFA class or long-term physical stability. However, there was a slight tendency for compounds with a relatively larger molecular weight, higher glass transition temperature, higher crystallization temperature, higher melting point and higher reduced glass transition temperature to have better GFA and better physical stability. In contrast, a high heat of fusion and entropy of fusion seemed to have a negative impact on the GFA and physical stability of our dataset.
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Терехов, С. В. "Тепловые свойства вещества в рамках модели двухфазной системы." Физика твердого тела 64, no. 8 (2022): 1077. http://dx.doi.org/10.21883/ftt.2022.08.52710.352.
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It has been established that the relations of the two-phase system model are applicable for describing the thermal properties of solids with disordered and crystalline structures. It is shown that the model adequately describes the curves of isochronous and isothermal crys-tallization of amorphous alloys and thermal changes in the volume of their samples. It is also suitable for calculating the heat capacities and thermal expansion coefficients of sub-stances that are diverse in their physical nature.
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Терехов, С. В. "Тепловые свойства вещества в рамках модели двухфазной системы." Физика твердого тела 64, no. 8 (2022): 1077. http://dx.doi.org/10.21883/ftt.2022.08.52710.352.
Full textAbstract:
It has been established that the relations of the two-phase system model are applicable for describing the thermal properties of solids with disordered and crystalline structures. It is shown that the model adequately describes the curves of isochronous and isothermal crys-tallization of amorphous alloys and thermal changes in the volume of their samples. It is also suitable for calculating the heat capacities and thermal expansion coefficients of sub-stances that are diverse in their physical nature.
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Steigerwald, M. L., T. Siegrist, E. M. Gyorgy, B. Hessen, Y. U. Kwon, and S. M. Tanzler. "effect of Diverse Ligands on the Course of a Molecules-to-Solids Process and Properties of Its Intermediates." Inorganic Chemistry 33, no. 15 (July 1994): 3389–95. http://dx.doi.org/10.1021/ic00093a030.
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Qu, Hua, and Wei Dong Liu. "Relationship between Valence Electron Structures and Mechanical Properties of ZL203." Applied Mechanics and Materials 152-154 (January 2012): 336–41. http://dx.doi.org/10.4028/www.scientific.net/amm.152-154.336.
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Based on the empirical electron theory of solids and molecules(EET) and valence electron theory of composition design of alloy, the valence electron structure(VES) of phases and phase interfaces of ZL203 are calculated in this paper, and the relationship between the VESs and mechanical properties are also studied. The results are as followed: 1) The of GP is bigger than of a, in other words, the resistance of dislocation movement in GP zone is bigger than that of in a matrix. 2) Compared with a matrix, the phases of q¢¢、q¢、q all have strengthening effects. From the bond combination of atoms composed in the strengthening phase of view, the strengthening effect of q is the best, that of q¢ is second, that of q¢¢ is the worst. 3) The precipitation sequence determined bynAis well accordance with that of depended on thermodynamics free energy. 4) The electron density difference Dr of a/GP, a/q" and a/q¢ interfaces increases one by one, and the stress of these interfaces also increases one by one, therefore the strength falls down one by one. 5) Combined with FSFs and ICFs, we can deduce that the best aging stage of ZL203 is the end of the precipitation of q¢¢ and the beginning of the precipitation of q¢.
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Mei, Baicheng, Yuxing Zhou, and Kenneth S. Schweizer. "Experimental test of a predicted dynamics–structure–thermodynamics connection in molecularly complex glass-forming liquids." Proceedings of the National Academy of Sciences 118, no. 18 (April 26, 2021): e2025341118. http://dx.doi.org/10.1073/pnas.2025341118.
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Understanding in a unified manner the generic and chemically specific aspects of activated dynamics in diverse glass-forming liquids over 14 or more decades in time is a grand challenge in condensed matter physics, physical chemistry, and materials science and engineering. Large families of conceptually distinct models have postulated a causal connection with qualitatively different “order parameters” including various measures of structure, free volume, thermodynamic properties, short or intermediate time dynamics, and mechanical properties. Construction of a predictive theory that covers both the noncooperative and cooperative activated relaxation regimes remains elusive. Here, we test using solely experimental data a recent microscopic dynamical theory prediction that although activated relaxation is a spatially coupled local–nonlocal event with barriers quantified by local pair structure, it can also be understood based on the dimensionless compressibility via an equilibrium statistical mechanics connection between thermodynamics and structure. This prediction is found to be consistent with observations on diverse fragile molecular liquids under isobaric and isochoric conditions and provides a different conceptual view of the global relaxation map. As a corollary, a theoretical basis is established for the structural relaxation time scale growing exponentially with inverse temperature to a high power, consistent with experiments in the deeply supercooled regime. A criterion for the irrelevance of collective elasticity effects is deduced and shown to be consistent with viscous flow in low-fragility inorganic network-forming melts. Finally, implications for relaxation in the equilibrated deep glass state are briefly considered.
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Kopelberg, M., I. L. Goldman, J. E. P. Debaene, and B. S. Schwartz. "Antiplatelet Activity is Positively Correlated with Pungency and Solids in Onion (Allium cepa L.)." HortScience 30, no. 4 (July 1995): 769A—769. http://dx.doi.org/10.21273/hortsci.30.4.769a.
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Onion (Allium cepa L.) and other vegetable Alliums have long been recognized for the antiplatelet properties. Consumers may benefit from the medicinal value of onions because they are commonly eaten raw in salads and the antiplatelet factor is destroyed by heat. Recent work indicates antiplatelet activity in Allium sp. may be due to the presence of native organosulfur compounds. The concentration of organosulfur compounds correlates positively with pungency, varies with onion cultivar, and is influenced by environmental factors. Bulb dry matter content, or solids, is positively correlated with pungency. Because antiplatelet activity may also be based on the activity of organosulfur compounds, it is possible these three factors are significantly correlated. The objective of this investigation was to examine the relationship among pungency, solids, and antiplatelet activity in four diverse onion genotypes. Replicated trials consisting of two mild and two pungent genotypes were conducted at four locations in 1994. Onion bulbs were harvested and analyzed for all three traits. Results from this investigation indicate significant positive correlations between antiplatelet activity, pungency, and solids in onion.
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Avsec, Jurij, and Igor Medveď. "Calculation of Thermodynamic Properties in Solid-Liquid, Solid-Gas and Liquid-Gas Region." Advanced Materials Research 1126 (October 2015): 1–8. http://dx.doi.org/10.4028/www.scientific.net/amr.1126.1.
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The paper features the mathematical model of analytical calculation of thermodynamic properties like viscosity, speed of sound and thermal conductivity for fluids in one and two-phase region (fluid-solid, fluid-gas) on the basis of statistical mechanics. For the calculation of thermal conductivity and viscosity for fluids will be presented Chung-Lee-Starling model Equations for the thermal conductivity are developed based on kinetic gas theories and correlated with the experimental data. The low-pressure transport properties are extended to fluids at high densities by introducing empirically correlated density dependent functions. These correlations use acentric factor, dimensionless dipole moment and an empirically determined association parameters to characterize molecular structure effect of polyatomic molecules. The calculation of thermodynamic properties for fluids was developed under the theory of statistical thermodynamics and statistical associated fluid theory. For the calculation of thermal conductivity of solids are the most important two contributions: the heat transport by electrons (el) and by phonons (ph). In our model we have made the assumption that heat transport by electrons and by phonons is independent and the thermal conductivity is than a sum of both terms.
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Guvench, Olgun, Devon Martin, and Megan Greene. "Pyranose Ring Puckering Thermodynamics for Glycan Monosaccharides Associated with Vertebrate Proteins." International Journal of Molecular Sciences 23, no. 1 (December 31, 2021): 473. http://dx.doi.org/10.3390/ijms23010473.
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The conformational properties of carbohydrates can contribute to protein structure directly through covalent conjugation in the cases of glycoproteins and proteoglycans and indirectly in the case of transmembrane proteins embedded in glycolipid-containing bilayers. However, there continue to be significant challenges associated with experimental structural biology of such carbohydrate-containing systems. All-atom explicit-solvent molecular dynamics simulations provide a direct atomic resolution view of biomolecular dynamics and thermodynamics, but the accuracy of the results depends on the quality of the force field parametrization used in the simulations. A key determinant of the conformational properties of carbohydrates is ring puckering. Here, we applied extended system adaptive biasing force (eABF) all-atom explicit-solvent molecular dynamics simulations to characterize the ring puckering thermodynamics of the ten common pyranose monosaccharides found in vertebrate biology (as represented by the CHARMM carbohydrate force field). The results, along with those for idose, demonstrate that the CHARMM force field reliably models ring puckering across this diverse set of molecules, including accurately capturing the subtle balance between 4C1 and 1C4 chair conformations in the cases of iduronate and of idose. This suggests the broad applicability of the force field for accurate modeling of carbohydrate-containing vertebrate biomolecules such as glycoproteins, proteoglycans, and glycolipids.
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Araya-Sibaja, Andrea Mariela, Cinira Fandaruff, Krissia Wilhelm, José Roberto Vega-Baudrit, Teodolito Guillén-Girón, and Mirtha Navarro-Hoyos. "Crystal Engineering to Design of Solids: From Single to Multicomponent Organic Materials." Mini-Reviews in Organic Chemistry 17, no. 5 (August 11, 2020): 518–38. http://dx.doi.org/10.2174/1570193x16666190430153231.
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Primarily composed of organic molecules, pharmaceutical materials, including drugs and excipients, frequently exhibit physicochemical properties that can affect the formulation, manufacturing and packing processes as well as product performance and safety. In recent years, researchers have intensively developed Crystal Engineering (CE) in an effort to reinvent bioactive molecules with well-known, approved pharmacological effects. In general, CE aims to improve the physicochemical properties without affecting their intrinsic characteristics or compromising their stability. CE involves the molecular recognition of non-covalent interactions, in which organic materials are responsible for the regular arrangement of molecules into crystal lattices. Modern CE, encompasses all manipulations that result in the alteration of crystal packing as well as methods that disrupt crystal lattices or reduce the size of crystals, or a combination of them. Nowadays, cocrystallisation has been the most explored strategy to improve solubility, dissolution rate and bioavailability of Active Pharmaceutical Ingredients (API). However, its combinatorial nature involving two or more small organic molecules, and the use of diverse crystallisation processes increase the possible outcomes. As a result, numerous organic materials can be obtained as well as several physicochemical and mechanical properties can be improved. Therefore, this review will focus on novel organic solids obtained when CE is applied including crystalline and amorphous, single and multicomponent as well as nanosized ones, that have contributed to improving not only solubility, dissolution rate, bioavailability permeability but also, chemical and physical stability and mechanical properties.
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Van der Ven, A., J. C. Thomas, B. Puchala, and A. R. Natarajan. "First-Principles Statistical Mechanics of Multicomponent Crystals." Annual Review of Materials Research 48, no. 1 (July 2018): 27–55. http://dx.doi.org/10.1146/annurev-matsci-070317-124443.
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The importance of configurational, vibrational, and electronic excitations in crystalline solids of technological interest makes a rigorous treatment of thermal excitations an essential ingredient in first-principles models of materials behavior. This contribution reviews statistical mechanics approaches that connect a crystal's electronic structure to its thermodynamic and kinetic properties. We start with a description of a thermodynamic and kinetic framework for multicomponent crystals that integrates chemistry and mechanics, as well as nonconserved order parameters that track the degree of chemical order and group/subgroup structural distortions. The framework allows for spatial heterogeneities and naturally couples thermodynamics with kinetics. We next survey statistical mechanics approaches that rely on effective Hamiltonians to treat configurational, vibrational, and electronic degrees of freedom within multicomponent crystals. These Hamiltonians, when suitably constructed, are capable of extrapolating first-principles electronic structure calculations within (kinetic) Monte Carlo simulations, thereby enabling first-principles predictions of equilibrium and nonequilibrium materials properties at finite temperature.
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Miletic, Rade, and Svetlana Paunovic. "Research into service tree (Sorbus domestica L.) population in eastern Serbia." Genetika 44, no. 3 (2012): 483–90. http://dx.doi.org/10.2298/gensr1203483m.
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All fruit tree populations along with the service tree (Sorbus domestica L.) population offer a wealth of diverse genetic material which is essential for the selection and creation of new cultivars and rootstocks. The main objective of the study was to evaluate the service tree population in Eastern Serbia in order to single out good selections whose fruit can be used fresh or processed in the human diet, as well as genotypes suitable for the development of new cultivars and rootstocks. The service tree population was analyzed for tree age, tree size and major fruit properties (shape, size and soluble solids content). Small-sized, medium to large and large fruits ranging in weight from 7.5-9.8 g, 10.3-18.6 g and 21.7-25.6 g were found in 52.3%, 41.1% and 6.60% trees, respectively, within the test population. Fruit length was 18.6-33.4 mm, fruit thickness 22.8-37.4 mm, stalk length 1.8-3.7 mm, soluble solids content 15.7-22.5%. The study also presents properties of some superior trees which require greater attention in terms of propagation, collection activities and commercial cultivation.
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Roth, Wieslaw J., Takayoshi Sasaki, Karol Wolski, Yeji Song, Dai-Ming Tang, Yasuo Ebina, Renzhi Ma, et al. "Liquid dispersions of zeolite monolayers with high catalytic activity prepared by soft-chemical exfoliation." Science Advances 6, no. 12 (March 2020): eaay8163. http://dx.doi.org/10.1126/sciadv.aay8163.
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The most effective approach to practical exploitation of the layered solids that often have unique valuable properties—such as graphene, clays, and other compounds—is by dispersion into colloidal suspensions of monolayers, called liquid exfoliation. This fundamentally expected behavior can be used to deposit monolayers on supports or to reassemble into hierarchical materials to produce, by design, catalysts, nanodevices, films, drug delivery systems, and other products. Zeolites have been known as extraordinary catalysts and sorbents with three-dimensional structures but emerged as an unexpected new class of layered solids contributing previously unknown valuable features: catalytically active layers with pores inside or across. The self-evident question of layered zeolite exfoliation has remained unresolved for three decades. Here, we report the first direct exfoliation of zeolites into suspension of monolayers as proof of the concept, which enables diverse applications including membranes and hierarchical catalysts with improved access.
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Şengül, Yasemin. "Nonlinear viscoelasticity of strain rate type: an overview." Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences 477, no. 2245 (January 2021): 20200715. http://dx.doi.org/10.1098/rspa.2020.0715.
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There are some materials in nature that experience deformations that are not elastic. Viscoelastic materials are some of them. We come across many such materials in our daily lives through a number of interesting applications in engineering, material science and medicine. This article concerns itself with modelling of the nonlinear response of a class of viscoelastic solids. In particular, nonlinear viscoelasticity of strain rate type, which can be described by a constitutive relation for the stress function depending not only on the strain but also on the strain rate, is considered. This particular case is not only favourable from a mathematical analysis point of view but also due to experimental observations, knowledge of the strain rate sensitivity of viscoelastic properties is crucial for accurate predictions of the mechanical behaviour of solids in different areas of applications. First, a brief introduction of some basic terminology and preliminaries, including kinematics, material frame-indifference and thermodynamics, is given. Then, considering the governing equations with constitutive relationships between the stress and the strain for the modelling of nonlinear viscoelasticity of strain rate type, the most general model of interest is obtained. Then, the long-term behaviour of solutions is discussed. Finally, some applications of the model are presented.
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Lan, Tian, and Zhaoyan Zhu. "Renormalized Phonon Microstructures at High Temperatures from First-Principles Calculations: Methodologies and Applications in Studying Strong Anharmonic Vibrations of Solids." Advances in Condensed Matter Physics 2016 (2016): 1–11. http://dx.doi.org/10.1155/2016/2714592.
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While the vibrational thermodynamics of materials with small anharmonicity at low temperatures has been understood well based on the harmonic phonons approximation, at high temperatures, this understanding must accommodate how phonons interact with other phonons or with other excitations. To date the anharmonic lattice dynamics is poorly understood despite its great importance, and most studies still rely on the quasiharmonic approximations. We shall see that the phonon-phonon interactions give rise to interesting coupling problems and essentially modify the equilibrium and nonequilibrium properties of materials, for example, thermal expansion, thermodynamic stability, heat capacity, optical properties, thermal transport, and other nonlinear properties of materials. The review aims to introduce some recent developements of computational methodologies that are able to efficiently model the strong phonon anharmonicity based on quantum perturbation theory of many-body interactions and first-principles molecular dynamics simulations. The effective potential energy surface of renormalized phonons and structures of the phonon-phonon interaction channels can be derived from these interdependent methods, which provide both macroscopic and microscopic perspectives in analyzing the strong anharmonic phenomena while the traditional harmonic models fail dramatically. These models have been successfully performed in the studies on the temperature-dependent broadenings of Raman and neutron scattering spectra, high temperature phase stability, and negative thermal expansion of rutile and cuprite structures, for example.
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Soni, Surbhi, Gunjan Chauhan, Bhawna Pareek, Pankaj Sharma, and Rajan Chopra. "Binary Liquid Mixtures Nonanol and Decanol with their Thermodynamic and Transport Behavior: A Review." Research Journal of Chemistry and Environment 26, no. 9 (August 25, 2022): 167–74. http://dx.doi.org/10.25303/2609rjce1670174.
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The extensive knowledge about structural phenomena of mixtures is of indispensable importance in the development of theories in liquid state. The information about structural and molecular interactions of liquid mixtures is quite vital from both fundamental and engineering point of view and can be utilized for further studies. For a better understanding of the non-ideal behavior of complex systems, fundamental thermodynamic and thermo-physical properties are the varied sources in which information is required. The excess thermodynamic properties are very sensitive to variables such as size, shape, composition, temperature and pressure, therefore an important information about the differences in the intermolecular interactions was obtained using these binary liquid mixtures under a range of physiochemical conditions. By using thermodynamics quantities, we can calculate the deviation of thermodynamics properties from those of an ideal mixture. These properties are necessary for the development of thermodynamic models required in optimized processes of the chemical, petrochemical, pharmaceutical and other industries. Along with diverse industrial applications, binary liquid mixtures can have hazardous effects such as pollutants causing air, water and soil contamination and some of them may have cancerous features. Their organic compounds and derivatives prepared from them are employed in a range of industrial and consumer applications such as perfumes, cosmetics, paints, varnishes, drugs, fuels, explosives, fats, dyes, waxes, resins, plastics, rubber, detergents, DDT etc. making them commercially important.
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Lu, S., N. Yao, and I. A. Aksay. "Chemical Compostion Analysis on Sintered Gold and Platinum Nanoparticles." Microscopy and Microanalysis 6, S2 (August 2000): 28–29. http://dx.doi.org/10.1017/s1431927600032633.
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Nanoparticles continue to attract interests because they fall into intermediate stage between molecular and macroscopic materials. Due to their large surface-to-volume ratio, nanoparticles exhibit physical and chemical properties that differ markedly from those characterizing the bulk solid state. One example is the phase diagram of a nanomaterial. Because nanocrystals display clear changes in both the thermodynamics and the kinetics of phase transitions, we expect different solubility limits in the nanometer regime. This means that phases unstable or unobserved in extended solids may be prepared as nanocrystals. We synthesized Au and Pt nanoparticles and performed chemical analysis on the sintered agglomerates.The colloidal Au and Pt particles were synthesized according to Turkevich's method. An aqueous AuCl3 solution (50mg Au/L) was heated to 70°C. A determined amount of lwt% aqueous sodium citrate dihydrate (Na3C6H5O7.2H2O) solution was added such that the citrate-to-Au mass ratio was 10.
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Collivignarelli, Maria Cristina, Sara Todeschini, Stefano Bellazzi, Marco Carnevale Miino, Francesca Maria Caccamo, Silvia Calatroni, Marco Baldi, and Sauro Manenti. "Understanding the Influence of Diverse Non-Volatile Media on Rheological Properties of Thermophilic Biological Sludge and Evaluation of Its Thixotropic Behaviour." Applied Sciences 12, no. 10 (May 20, 2022): 5198. http://dx.doi.org/10.3390/app12105198.
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In this study, the rheological properties of thermophilic biological sludge (TBS) have been investigated evaluating the influence of non-volatile solids (NVS). Calcium carbonate, sand, and sodium bentonite were separately added to the sludge to evaluate the effect of concentration and type of NVS. Results show that TBS consistency coefficient significantly enhanced increasing sodium bentonite concentration. On the contrary, calcium carbonate and sand showed relatively small influence on the rheological properties of TBS. Thixotropic behaviour of TBS has also been investigated and is more pronounced at higher shear rate (1000 s−1). Double exponential fitting model was the best choice to represent thixotropic behaviour in case of low (100 s−1) and high shear rate (1000 s−1), while a single-exponential model represents the best option in case of medium shear rate (400 s−1).
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Hassan, Mohsan, Sajid Ali, Walid Aich, Faical Khlissa, Badreddine Ayadi, and Lioua Kolsi. "Transport pattern of Non-Newtonian mass and thermal energy under two diverse flow conditions by using modified models for thermodynamics properties." Case Studies in Thermal Engineering 29 (January 2022): 101714. http://dx.doi.org/10.1016/j.csite.2021.101714.
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Smith, Matthew D., Ethan J. Crace, Adam Jaffe, and Hemamala I. Karunadasa. "The Diversity of Layered Halide Perovskites." Annual Review of Materials Research 48, no. 1 (July 2018): 111–36. http://dx.doi.org/10.1146/annurev-matsci-070317-124406.
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The two-dimensional congeners of the well-known three-dimensional perovskites display new properties enabled by their reduced dimensionality. Here, organic molecules separate inorganic sheets, affording the properties of both discrete molecules and extended solids in single, well-defined materials. The choice of organic and inorganic components engenders a large range of structural motifs, which yield diverse properties such as electroluminescence, white-light emission, photoconductivity, porosity, and reactivity. Layered halide perovskites have been known for decades. Their recent resurgence compels us to understand the fundamental studies that set the stage for their current technological relevance. We are not providing a comprehensive review of this vast and rapidly growing field. Instead, we highlight some of the discoveries that have directed current research in this field. We hope to introduce new researchers to layered halide perovskites to bring fresh perspectives to study this venerable family of materials that continue to surprise us today.
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Casanellas, Jordi, and Ilídio Lopes. "The Sun and stars: Giving light to dark matter." Modern Physics Letters A 29, no. 37 (December 4, 2014): 1440001. http://dx.doi.org/10.1142/s021773231440001x.
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During the last century, with the development of modern physics in such diverse fields as thermodynamics, statistical physics, and nuclear and particle physics, the basic principles of the evolution of stars have been successfully well understood. Nowadays, a precise diagnostic of the stellar interiors is possible with the new fields of helioseismology and astroseismology. Even the measurement of solar neutrino fluxes, once a problem in particle physics, is now a powerful probe of the core of the Sun. These tools have allowed the use of stars to test new physics, in particular the properties of the hypothetical particles that constitute the dark matter (DM) of the Universe. Here we present recent results obtained using this approach.
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Choudhuri, Indrani, and Donald Truhlar. "Improved Predictive Tools for Structural Properties of Metal–Organic Frameworks." Molecules 25, no. 7 (March 28, 2020): 1552. http://dx.doi.org/10.3390/molecules25071552.
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The accurate determination of structural parameters is necessary to understand the electronic and magnetic properties of metal–organic frameworks (MOFs) and is a first step toward accurate calculations of electronic structure and function for separations and catalysis. Theoretical structural determination of metal-organic frameworks is particularly challenging because they involve ionic, covalent, and noncovalent interactions, which must be treated in a balanced fashion. Here, we apply a diverse group of local exchange-correlation functionals (PBE, PBEsol, PBE-D2, PBE-D3, vdW-DF2, SOGGA, MN15-L, revM06-L, SCAN, and revTPSS) to a broad test set of MOFs to seek the most accurate functionals to study various structural aspects of porous solids, in particular to study lattice constants, unit cell volume, two types of pore size characteristics, bond lengths, bond angles, and torsional angles). The recently developed meta functionals revM06-L and SCAN, without adding any molecular mechanics terms, are able to predict more accurate structures than previously recommended functionals, both those without molecular mechanics terms (PBE, PBEsol, vdW-DF2, and revTPSS) and those with them (PBE-D2 and PBE-D3). To provide a broader test, these two functionals are also tested for lattice constants and band gaps of unary, binary, and ternary semiconductors.
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Gujrati, Purushottam Das. "Foundations of Nonequilibrium Statistical Mechanics in Extended State Space." Foundations 3, no. 3 (August 23, 2023): 419–548. http://dx.doi.org/10.3390/foundations3030030.
Full textAbstract:
The review provides a pedagogical but comprehensive introduction to the foundations of a recently proposed statistical mechanics (μNEQT) of a stable nonequilibrium thermodynamic body, which may be either isolated or interacting. It is an extension of the well-established equilibrium statistical mechanics by considering microstates mk in an extended state space in which macrostates (obtained by ensemble averaging A^) are uniquely specified so they share many properties of stable equilibrium macrostates. The extension requires an appropriate extended state space, three distinct infinitessimals dα=(d,de,di) operating on various quantities q during a process, and the concept of reduction. The mechanical process quantities (no stochasticity) like macrowork are given by A^dαq, but the stochastic quantities C^αq like macroheat emerge from the commutator C^α of dα and A^. Under the very common assumptions of quasi-additivity and quasi-independence, exchange microquantities deqk such as exchange microwork and microheat become nonfluctuating over mk as will be explained, a fact that does not seem to have been appreciated so far in diverse branches of modern statistical thermodynamics (fluctuation theorems, quantum thermodynamics, stochastic thermodynamics, etc.) that all use exchange quantities. In contrast, dqk and diqk are always fluctuating. There is no analog of the first law for a microstate as the latter is a purely mechanical construct. The second law emerges as a consequence of the stability of the system, and cannot be violated unless stability is abandoned. There is also an important thermodynamic identity diQ≡diW≥0 with important physical implications as it generalizes the well-known result of Count Rumford and the Gouy-Stodola theorem of classical thermodynamics. The μNEQT has far-reaching consequences with new results, and presents a new understanding of thermodynamics even of an isolated system at the microstate level, which has been an unsolved problem. We end the review by applying it to three different problems of fundamental interest.