scholarly journals Thermodynamic properties of sodium aluminosilicate hydrate (N-A-S-H)

2021 ◽  
Author(s):  
Brant Walkley ◽  
Xinyuan Ke ◽  
Oday Hussein ◽  
John L Provis
Keyword(s):  
Thermodynamic Properties ◽  
Systematic Investigation ◽  
Sodium Aluminosilicate ◽  
Sodium Aluminosilicate Hydrate ◽  
First Time

This study presents for the first time a systematic investigation of the thermodynamic properties of sodium aluminosilicate hydrate (N-A-S-H), through dissolution of pure synthetic N-A-S-H gels. Changes to the chemical...

Thermodynamic Properties of CaSiO3 Perovskite at High Pressure and High Temperature

2009 ◽  
Vol 64 (5-6) ◽  
pp. 399-404 ◽  
Author(s):  
Zi-Jiang Liu ◽  
Xiao-Ming Tan ◽  
Yuan Guo ◽  
Xiao-Ping Zheng ◽  
Wen-Zhao Wu
Keyword(s):  
Thermodynamic Properties ◽  
First Principles ◽  
Density Functional ◽  
High Pressures ◽  
Local Density ◽  
Harmonic Approximation ◽  
Debye Model ◽  
Functional Theory ◽  
Casio3 Perovskite ◽  
First Time

The thermodynamic properties of tetragonal CaSiO3 perovskite are predicted at high pressures and temperatures using the Debye model for the first time. This model combines the ab initio calculations within local density approximation using pseudopotentials and a plane wave basis in the framework of density functional theory, and it takes into account the phononic effects within the quasi-harmonic approximation. It is found that the calculated equation of state is in excellent agreement with the observed values at ambient condition. Based on the first-principles study and the Debye model, the thermal properties including the Debye temperature, the heat capacity, the thermal expansion and the entropy are obtained in the whole pressure range from 0 to 150 GPa and temperature range from 0 to 2000 K.

scholarly journals Heat Capacities and Thermodynamic Properties of Hungchaoite and Mcallisterite

Molecules ◽  
2019 ◽  
Vol 24 (24) ◽  
pp. 4470
Author(s):  
Jiangtao Song ◽  
Fei Yuan ◽  
Long Li ◽  
Yafei Guo ◽  
Tianlong Deng
Keyword(s):  
Phase Transition ◽  
Thermodynamic Properties ◽  
Thermodynamic Functions ◽  
Process Design ◽  
Chemical Engineering ◽  
Heat Capacities ◽  
Salt Lakes ◽  
Engineering Process ◽  
Thermal Anomalies ◽  
First Time

The heat capacities on two minerals of hungchaoite (MgB4O7·9H2O, Hu) and mcallisterite (MgB6O10·7.5H2O, Mc) have been measured with a precision calorimeter at temperatures ranging from 306.15 to 355.15 K, experimentally. It was found that there are no phase transition and thermal anomalies, and the molar heat capacities against temperature for the minerals of hungchaoite and mcallisterite were fitted as C p , m , Hu   =   − 27019.23675 + 229.55286 T   −   0.63912 T   2   +   ( 5.95862   ×   10   − 4 )   T   3 and C p , mMc   =   − 9981.88552   +   84.10964 T   −   0.22685 T   2   +   ( 2.0593   ×   10   − 4 )   T   3 , respectively. The molar heat capacities and thermodynamic functions of (HT-H298.15), (ST-S298.15), and (GT-G298.15) at intervals of 1 K for the two minerals were obtained for the first time. These results are significant in order to understand the thermodynamic properties of those minerals existing in nature salt lakes, as well as applying them to the chemical engineering process design.

THERMODYNAMIC PROPERTIES OF MgSiO3 POST-PEROVSKITE

2010 ◽  
Vol 24 (03) ◽  
pp. 315-324
Author(s):  
ZI-JIANG LIU ◽  
XIAO-WEI SUN ◽  
CAI-RONG ZHANG ◽  
LI-NA TIAN ◽  
YUAN GUO
Keyword(s):  
Thermodynamic Properties ◽  
First Principles ◽  
Density Functional ◽  
High Pressures ◽  
Local Density ◽  
Harmonic Approximation ◽  
Debye Model ◽  
Functional Theory ◽  
High Pressures And Temperatures ◽  
First Time

The thermodynamic properties of MgSiO 3 post-perovskite are predicted at high pressures and temperatures using the Debye model for the first time. This model combines with ab initio calculations within local density approximation using pseudopotentials and a plane wave basis in the framework of density functional theory, and it takes into account the phononic effects within the quasi-harmonic approximation. It is found that the calculated equation of state of MgSiO 3 post-perovskite is in excellent agreement with the latest observed values. Based on the first-principles study and the Debye model, the thermal properties including the Debye temperature, the heat capacity, the thermal expansion, and the entropy are obtained in the whole pressure range from 0 to 150 GPa and temperature range from 0 to 2000 K.

Guided Inquiry Learning in a Thermodynamics Class

2010 ◽  
Author(s):  
Brandon S. Field
Keyword(s):  
Thermodynamic Properties ◽  
Student Performance ◽  
Inquiry Learning ◽  
Carnot Cycle ◽  
Brayton Cycle ◽  
Guided Inquiry ◽  
Stirling Cycle ◽  
Class A ◽  
Or Groups ◽  
First Time

This paper describes guided inquiry investigations of thermodynamic properties and cycles that was used in a sophomore thermodynamics class. A partially-complete computer model of a Carnot cycle was provided to students that was written in Engineering Equation Solver (EES). The students were led through a investigation in pairs or groups using the model designed to familiarize the students with the software as well as the cycle. As part of the investigation, the students were required to modify the model to add features. Following the in-class exercise with the Carnot cycle, students were required to model a Stirling cycle and later a Brayton cycle using the same EES software for a take-home project. In previous classes, the same (and similar) take-home projects were assigned, but this was the first time that these computer projects were preceded by a guided inquiry investigation. The advantages of using such a guided inquiry investigation to introduce the software were primarily evident from the questions that were avoided on the take-home projects, but also evident from the student performance on the projects themselves. A discussion of the investigation is included, as well as critique of what will be changed for the next time the class is taught.

scholarly journals Characterization of Slag Reprocessing Tailings-Based Geopolymers in Marine Environment

Minerals ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 832 ◽  
Author(s):  
Jie Wu ◽  
Jing Li ◽  
Feng Rao ◽  
Wanzhong Yin
Keyword(s):  
Compressive Strength ◽  
Marine Environment ◽  
Copper Slag ◽  
X Ray Diffraction ◽  
Strength Measurement ◽  
X Ray ◽  
Sodium Aluminosilicate ◽  
Marine Concrete ◽  
Sodium Aluminosilicate Hydrate

In this study, copper slag reprocessing tailings (CSRT) were synthesized into geopolymers with 40%, 50% and 60% metakaolin. The evolution of compressive strength and microstructures of CSRT-based geopolymers in a marine environment was investigated. Except for compressive strength measurement, the characterizations of X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), nuclear magnetic resonance (NMR) and scanning electron microscopy (SEM) were included. It was found that marine conditions changed the Si/Al ratio in the sodium-aluminosilicate-hydrate (N-A-S-H) gel backbone, promoted the geopolymerization process, led to more Q4(3Al), Q4(2Al) and Q4(1Al) gel formation and a higher compressive strength of the geopolymers. This provided a basis for the preparation of CSRT-based geopolymers into marine concrete.

New Equations for the Thermodynamic Properties of Saturated Water in Both the Liquid and Vapour Phases

1967 ◽  
Vol 9 (1) ◽  
pp. 24-35 ◽  
Author(s):  
M. R. Gibson ◽  
E. A. Bruges
Keyword(s):  
Thermodynamic Properties ◽  
Chebyshev Polynomials ◽  
Vapour Pressure ◽  
Temperature Relationship ◽  
National Bureau ◽  
Tabular Form ◽  
Saturated Liquid ◽  
Saturated Water ◽  
First Time

Equations in the form of Chebyshev polynomials are presented which enable the thermodynamic properties of saturated water in its liquid and vapour phases to be calculated in a systematic manner. In the equations defining the pressure-temperature relationship the authors have made allowance for certain unpublished observations of the National Bureau of Standards and these are considered in the section relating to vapour pressure. It is believed that the assembly of equations specify for the first time the saturated liquid and vapour boundaries whose properties have previously only been available in tabular form.

Atomistic Study on the Structure and Thermodynamic Properties of Afe2al10 (A = Th, U)

2011 ◽  
Vol 261-263 ◽  
pp. 735-739
Author(s):  
Li Jun Bai ◽  
Ping Qian ◽  
Yao Wen Hu ◽  
Jiu Li Liu
Keyword(s):  
Thermodynamic Properties ◽  
Lattice Parameters ◽  
Inversion Method ◽  
Vibrational Entropy ◽  
Interatomic Distances ◽  
Pair Potentials ◽  
Densities Of States ◽  
Atomistic Study ◽  
First Time ◽  
Dynamic Phenomena

An atomistic study is presented on the phase stability, interatomic distances and lattice parameters of the new actinide intermetallic compounds AFe2Al10(A = Th, U). Calculations are based on a series of interatomic pair potentials related to the actinides and transition metals, which are obtained by lattice inversion method. The cohesive energy of AFe2Al10with two possible structures of YbFe2Al10-type and ThMn12-type are calculated and compared with each other. Calculated lattice parameters of AFe2Al10are found to agree with reports in the literatures. In particular, the phonon densities of states, vibrational entropy and Debye temperature related to dynamic phenomena are evaluated for the first time.

Auger Electron Spectroscopical Investigation of Interfacial Segregation in the Cu-Bi System

2005 ◽  
Vol 237-240 ◽  
pp. 1141-1146
Author(s):  
Gabriel A. López ◽  
Eric J. Mittemeijer
Keyword(s):  
Grain Boundary ◽  
Auger Electron ◽  
Surface Segregation ◽  
Vacuum Chamber ◽  
Systematic Investigation ◽  
Special Method ◽  
Free Surfaces ◽  
Internal Cavities ◽  
Bi Segregation ◽  
First Time

A systematic investigation of the segregation of Bi at both free surfaces and grain boundaries in Cu, under identical conditions, is reported. The problem of Bi evaporation upon Bi segregation at free surfaces was overcome using a special method for sample preparation. Cu bicrystals containing deliberately made internal cavities at the grain boundary were doped with Bi, annealed at temperatures between 1073 and 1223 K, and broken along the grain boundary in an ultrahigh vacuum chamber for Auger electron spectroscopy. For the first time, the equilibrium surface segregation of Bi in Cu has been measured. The segregation at the free surface was found to be stronger than the segregation at the grain boundary.

scholarly journals Design Space of Flexible Multigigabit LDPC Decoders

VLSI Design ◽  
2012 ◽  
Vol 2012 ◽  
pp. 1-10 ◽  
Author(s):  
Philipp Schläfer ◽  
Christian Weis ◽  
Norbert Wehn ◽  
Matthias Alles
Keyword(s):  
Design Space ◽  
State Of The Art ◽  
Cmos Technology ◽  
Systematic Investigation ◽  
Design Parameters ◽  
Ldpc Decoder ◽  
The Past ◽  
Ieee 802.11Ad ◽  
Decoder Design ◽  
First Time

Multigigabit LDPC decoders are demanded by standards like IEEE 802.15.3c and IEEE 802.11ad. To achieve the high throughput while supporting the needed flexibility, sophisticated architectures are mandatory. This paper comprehensively presents the design space for flexible multigigabit LDPC applications for the first time. The influence of various design parameters on the hardware is investigated in depth. Two new decoder architectures in a 65 nm CMOS technology are presented to further explore the design space. In the past, the memory domination was the bottleneck for throughputs of up to 1 Gbit/s. Our systematic investigation of column- versus row-based partially parallel decoders shows that this is no more a bottleneck for multigigabit architectures. The evolutionary progress in flexible multigigabit LDPC decoder design is highlighted in an extensive comparison of state-of-the-art decoders.

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