scholarly journals First-principles anharmonic quantum calculations for peptide spectroscopy: VSCF calculations and comparison with experiments

2016 ◽  
Vol 18 (3) ◽  
pp. 1607-1614 ◽  
Author(s):  
Tapta Kanchan Roy ◽  
Rahul Sharma ◽  
R. Benny Gerber
Keyword(s):  
Experimental Data ◽  
Vibrational Spectroscopy ◽  
First Principles ◽  
Quantum Calculations ◽  
Comparison With Experiments

First-principles quantum calculations for anharmonic vibrational spectroscopy of three protected dipeptides are carried out and compared with experimental data.

scholarly journals A thermodynamic description of metastable c-TiAlZrN coatings with triple spinodally decomposed domains

2017 ◽  
Vol 53 (2) ◽  
pp. 85-93 ◽  
Author(s):  
J. Zhou ◽  
L. Zhang ◽  
L. Chen ◽  
Y. Du ◽  
Z.K. Liu
Keyword(s):  
Experimental Data ◽  
Phase Equilibria ◽  
First Principles ◽  
Thermodynamic Description ◽  
Quantitative Description ◽  
Experimental Phase Equilibria ◽  
Free Energies ◽  
Calphad Technique ◽  
Important Input ◽  
Good Agreement

A critical thermodynamic assessment of the metastable c-TiAlZrN coatings, which are reported to spinodally decompose into triple domains, i.e., c-TiN, c-AlN, and c-ZrN, was performed via the CALculation of PHAse Diagram (CALPHAD) technique based on the limited experimental data as well as the first-principles computed free energies. The metastable c-TiAlZrN coatings were modeled as a pseudo-ternary phase consisting of c-TiN, c-AlN and c-ZrN species, and described using the substitutional solution model. The thermodynamic descriptions for the three boundary binaries were directly taken from either the CALPHAD assessment or the first-principles results available in the literature except for a re-adjustment of the pseudo-binary c-AlN/c-ZrN system based on the experimental phase equilibria in the pseudo-ternary system. The good agreement between the calculated phase equilibria and the experimental data over the wide temperature range was obtained, validating the reliability of the presently obtained thermodynamic descriptions for the c-TiAlZrN system. Based on the present thermodynamic description, different phase diagrams and thermodynamic properties can be easily predicted. It is anticipated that the present thermodynamic description of the metastable c-TiAlZrN coatings can serve as the important input for the later quantitative description of the microstructure evolution during service life.

scholarly journals An approach to determine enthalpies of formation for ternary compounds

2010 ◽  
Vol 46 (1) ◽  
pp. 1-9 ◽  
Author(s):  
Y. Du ◽  
J. Wang ◽  
Y.F. Ouyang ◽  
L.J. Zhang ◽  
Z.H. Yuan ◽  
...  
Keyword(s):  
Experimental Data ◽  
First Principles ◽  
Integrated Approach ◽  
Enthalpies Of Formation ◽  
Calphad Approach ◽  
Miedema Model ◽  
Theoretical Computation ◽  
Ternary Compounds ◽  
Data Yield ◽  
Experimental Values

An integrated approach of experiment and theoretical computation to acquire enthalpies of formation for ternary compounds is described. The enthalpies of formation (DHf ) for Al71Fe19Si10 and Al31Mn6Ni2 are measured via a calorimeter. Miedema model, CALPHAD and first-principles method are employed to calculate DHf for the above compounds and several Al-based ternary compounds. It is found that first-principles generated data yield good agreements with experimental values and thus can be used as key 'experimental data', which are needed for CALPHAD approach.

First-Principles Approach to Mn-Doped Group IV Semiconductors: Comparison with Experiments and Outlook

2006 ◽  
Vol 52 ◽  
pp. 11-20
Author(s):  
Alessandra Continenza ◽  
Silvia Picozzi ◽  
Gianni Profeta ◽  
Luca Ottaviano ◽  
Maurizio Passacantando ◽  
...  
Keyword(s):  
First Principles ◽  
Density Functional ◽  
Magnetic Semiconductor ◽  
Group Iv ◽  
High Integrability ◽  
Group Iv Semiconductors ◽  
Ge Matrix ◽  
Small Clusters ◽  
Mn Doped ◽  
Comparison With Experiments

We present an extensive theoretical and experimental study of the Mn-Ge dilute magnetic semiconductor, a material which - due to its high integrability with mainstream Si technology - may hold good promises for spintronic applications. Ab-initio calculations on several different systems containing isolated Mn impurities as well as small clusters (up to three Mn impurities) show that Mn has a tendency to segregate into the Ge matrix and to stabilize occupation of interstitial sites if these are coordinated with other Mn occupying substitutional sites nearby. Several different experimental characterizations (HRTEM, XRD, UPS, MOKE) performed on Mn ion-implanted systems are analyzed and discussed: a close comparison betweeen experimental evidences and density functional calculations allows a full understanding of the sample properties and to disentagle the contributions coming from the diluted and segregated phases. The complexity of this system shows that much has to be done still to understand the physics of these materials and to undisclose all their possible applications.

scholarly journals Cluster size and composition dependent water deprotonation by free manganese oxide clusters

2016 ◽  
Vol 18 (23) ◽  
pp. 15727-15737 ◽  
Author(s):  
Sandra M. Lang ◽  
Thorsten M. Bernhardt ◽  
Denis M. Kiawi ◽  
Joost M. Bakker ◽  
Robert N. Barnett ◽  
...  
Keyword(s):  
Manganese Oxide ◽  
Water Splitting ◽  
Vibrational Spectroscopy ◽  
First Principles ◽  
Cluster Size ◽  
First Principles Calculations ◽  
Future Design ◽  
Basic Concepts ◽  
Molecular Catalysts ◽  
Artificial Water

Vibrational spectroscopy and first-principles calculations reveal basic concepts of the interaction between manganese oxide clusters and water which could aid the future design of artificial water-splitting molecular catalysts.

Deformation Mechanism of Nanocrystalline Al-Fe Alloys by Analysis from Ab-Initio Calculations

2006 ◽  
Vol 503-504 ◽  
pp. 209-214 ◽  
Author(s):  
Tokuteru Uesugi ◽  
Yorinobu Takigawa ◽  
Kenji Higashi
Keyword(s):  
Experimental Data ◽  
Solid Solution ◽  
Yield Strength ◽  
First Principles ◽  
High Strength ◽  
Misfit Strain ◽  
Solid Solution Strengthening ◽  
Solution Strengthening ◽  
Fe Alloys ◽  
Quench Method

Recently nanocrystalline Al-Fe alloys produced by a vapor quench method have been reported. These alloys are supersaturated solid solution and exhibit high strength with good ductility. It is postulated that the high strength of the Al-Fe alloys could be achieved by both the nano-grained structures and the solid solution strengthening. The contribution to the yield strength due to both the grain size strengthening and the solid solution strengthening were analyzed from the experimental data. Then the contribution to the yield strength due to the solid solution strengthening was estimated from the misfit strain calculated from the first principles in order to compare with analytical results estimated from the experimental data.

Surface enhanced vibrational spectroscopy and first-principles study of l-cysteine adsorption on noble trimetallic Au/Pt@Rh clusters

2015 ◽  
Vol 17 (33) ◽  
pp. 21268-21277 ◽  
Author(s):  
B. Loganathan ◽  
V. L. Chandraboss ◽  
S. Senthilvelan ◽  
B. Karthikeyan
Keyword(s):  
Vibrational Spectroscopy ◽  
First Principles ◽  
Surface Complex ◽  
First Principles Study ◽  
Surface Enhanced ◽  
Complex Calculation

First-principles study of l-cysteine adsorption on noble trimetallic Au/Pt@Rh clusters has been discussed in the light of SEIRS and theoretical surface complex calculation.

scholarly journals Modelling of a low-temperature differential Stirling engine

2007 ◽  
Vol 221 (8) ◽  
pp. 927-943 ◽  
Author(s):  
A Robson ◽  
T Grassie ◽  
J Kubie
Keyword(s):  
Experimental Data ◽  
Theoretical Model ◽  
Low Temperature ◽  
First Principles ◽  
Dynamic Behaviour ◽  
Stirling Engine ◽  
Current Paper ◽  
Temperature Differential ◽  
Good Agreement

A full theoretical model of a low-temperature differential Stirling engine is developed in the current paper. The model, which starts from the first principles, gives a full differential description of the major components of the engine: the behaviour of the gas in the expansion and the compression spaces; the behaviour of the gas in the regenerator; the dynamic behaviour of the displacer; and the power piston/flywheel assembly. A small fully instrumented engine is used to validate the model. The theoretical model is in good agreement with the experimental data, and describes well all features exhibited by the engine.

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