Ionic interactions. Part 3.—Semi-empirical studies of the pyrazine-lithium ion-pair

1969 ◽  
Vol 65 (0) ◽  
pp. 3129-3135 ◽  
Author(s):  
T. A. Claxton ◽  
D. McWilliams
Keyword(s):  
Empirical Studies ◽  
Lithium Ion ◽  
Ion Pair ◽  
Ionic Interactions ◽  
Semi Empirical

scholarly journals Thermodynamic investigation of promethazine, loratadine, cetirizine and buclizine as antihistamine drugs; monte carlo and semi-empirical studies

2020 ◽  
Vol 33 (01) ◽  
pp. 94-108
Author(s):  
Mina Zakeri ◽  
Majid Monajjemi ◽  
Ali Ebrahimi
Keyword(s):  
Total Energy ◽  
Frequency Analysis ◽  
Empirical Studies ◽  
Zero Point ◽  
Heat Of Formation ◽  
Electronic Energy ◽  
Basis Set ◽  
Amber Force Field ◽  
Environment Temperature ◽  
Semi Empirical

In this article, we discussed about four antihistamine drug called promethazine, loratadine, cetirizine and buclizine. Promethazine in this list is the only one in first generation antihistamine classification with CNS sedation effect and the other three belongs to second generation antihistamine group which are non-sedation and used to treat in many different anti-allergenic fields. In the following we optimized potential, kinetic and total energy of these molecules at body temperature (310 k˚) and environment temperature (298 k ˚) using Mont Carlo method in Amber force field in 500 ns. The quantum mechanics calculations and molecular structure of these molecules investigated using B3LYP level of theory with 6-31 G (d) as a basis set. Theoretical computations were performed to study thermodynamic parameters and frequency analysis. Electronic, thermal, zero point and gibs free energy and enthalpy were estimated in frequency analysis. Semi empirical computations were summarized to pm3 method and different energy parameters (total energy, Binding Energy, Isolated Atomic Energy, Electronic Energy, Core–Core Interaction and Heat of Formation.

Capacity Loss Estimation For Li-Ion Batteries Based On A Semi-Empirical Model

2021 ◽  
Author(s):  
Mohammed Rabah ◽  
Eero Immonen ◽  
Sajad Shahsavari ◽  
Mohammad-Hashem Haghbayan ◽  
Kirill Murashko ◽  
...  
Keyword(s):  
Lithium Ion Batteries ◽  
Empirical Model ◽  
Lithium Ion ◽  
Average Error ◽  
Li Ion Batteries ◽  
Capacity Loss ◽  
Capacity Degradation ◽  
Battery Capacity ◽  
Li Ion ◽  
Semi Empirical

Understanding battery capacity degradation is instrumental for designing modern electric vehicles. In this paper, a Semi-Empirical Model for predicting the Capacity Loss of Lithium-ion batteries during Cycling and Calendar Aging is developed. In order to redict the Capacity Loss with a high accuracy, battery operation data from different test conditions and different Lithium-ion batteries chemistries were obtained from literature for parameter optimization (fitting). The obtained models were then compared to experimental data for validation. Our results show that the average error between the estimated Capacity Loss and measured Capacity Loss is less than 1.5% during Cycling Aging, and less than 2% during Calendar Aging. An electric mining dumper, with simulated duty cycle data, is considered as an application example.

scholarly journals Accelerated Aging Characterization of Lithium-ion Cells: Using Sensitivity Analysis to Identify the Stress Factors Relevant to Cyclic Aging

Batteries ◽  
2020 ◽  
Vol 6 (1) ◽  
pp. 6 ◽  
Author(s):  
Tanja Gewald ◽  
Adrian Candussio ◽  
Leo Wildfeuer ◽  
Dirk Lehmkuhl ◽  
Alexander Hahn ◽  
...  
Keyword(s):  
Sensitivity Analysis ◽  
Accelerated Aging ◽  
Lithium Ion ◽  
Simulation Models ◽  
Cell Types ◽  
Stress Factors ◽  
Worst Case ◽  
Lithium Ion Cells ◽  
Aging Models ◽  
Semi Empirical

As storage technology in electric vehicles, lithium-ion cells are subject to a continuous aging process during their service life that, in the worst case, can lead to a premature system failure. Battery manufacturers thus have an interest in the aging prediction during the early design phase, for which semi-empirical aging models are often used. The progress of aging is dependent on the application-specific load profile, more precisely on the aging-relevant stress factors. Still, a literature review reveals a controversy on the aging-relevant stress factors to use as input parameters for the simulation models. It shows that, at present, a systematic and efficient procedure for stress factor selection is missing, as the aging characteristic is cell-specific. In this study, an accelerated sensitivity analysis as a prior step to aging modeling is proposed, which is transferable and allows to determine the actual aging-relevant stress factors for a specific lithium-ion cell. For the assessment of this accelerated approach, two test series with different acceleration levels and cell types are performed and evaluated. The results show that a certain amount of charge throughput, 100 equivalent full cycles in this case, is necessary to conduct a statistically significant sensitivity analysis.

scholarly journals Ion-Pair Extraction of Lithium Ion by a Water-Soluble Porphyrin.

1997 ◽  
Vol 13 (Supplement) ◽  
pp. 119-122 ◽  
Author(s):  
Sun HAIPING ◽  
Jun NISHIMOTO ◽  
Masaaki TABATA
Keyword(s):  
Lithium Ion ◽  
Ion Pair ◽  
Water Soluble ◽  
Water Soluble Porphyrin

Extended lithium ion pair indicator scale in tetrahydrofuran

1998 ◽  
Vol 76 (6) ◽  
pp. 765-769 ◽  
Author(s):  
Andrew Streitwieser ◽  
Daniel Zerong Wang ◽  
Manolis Stratakis ◽  
Antonio Facchetti ◽  
Roustam Gareyev ◽  
...  
Keyword(s):  
Lithium Ion ◽  
Ion Pair ◽  
Organolithium Compounds ◽  
Cesium Ion ◽  
Pk Scale ◽  
Acidity Scale

The lithium pK scale has been extended to 25 indicators with a pK range of 9.7-24.4. The resulting scale is compared with the cesium ion pair acidities and to ionic pK's in DMSO and aqueous DMSO.Key words: ion pair acidity, organolithium compounds, indicator, acidity scale.

scholarly journals Folding domains and intramolecular ionic interactions of lysine residues in glyceraldehyde 3-phosphate dehydrogenase

1977 ◽  
Vol 161 (1) ◽  
pp. 49-62 ◽  
Author(s):  
J M Lambert ◽  
R N Perham
Keyword(s):  
Catalytic Activity ◽  
Aspartic Acid ◽  
Three Dimensional ◽  
Ion Pair ◽  
Dimensional Structure ◽  
Ionic Interactions ◽  
Rabbit Muscle ◽  
Amino Groups ◽  
Muscle Enzyme ◽  
Lysine Residues

1. Treatment with methyl acetimidate was used to probe the topography of several tetrameric glyceraldehyde 3-phosphate dehydrogenases, in particular the holoenzymes from rabbit muscle and Bacillus stearothermophilus. During the course of the reaction with the rabbit muscle enzyme, the number of amino groups fell rapidly from the starting value of 27 per subunit to a value of approx. five per subunit. This number could be lowered further to values between one and two per subunit by a second treatment with methyl acetimidate. The enzyme remained tetrameric throughout and retained 50% of its initial catalytic activity at the end of the experiment. 2. Use of methyl [1-14C]acetimidate and small-scale methods of protein chemistry showed that only one amino group per subunit, that of lysine-306, was completely unavailable for reaction with imido ester in the native enzyme. This results is consistent with the structure of the highly homologous glyceraldehyde 3-phosphate dehydrogenase of lobster muscle deduced from X-ray-crystallographic analysis, since lysine-306 can be seen to form an intrachain ion-pair with aspartic acid-241 in the hydrophobic environment of a subunit-subunit interface. 3. Several other amino groups in the rabbit muscle enzyme that reacted only slowly with the reagent were also identified chemically. These were found to be located entirely in the C-terminal half of the polypeptides chain, which comprises a folding domain associated with catalytic activity and subunit contact in the three-dimensional structure. Slow reaction of these ‘surface’ amino groups with methyl acetimidate is attributed to intramolecular ionic interactions of the amino groups with neighbouring side-chain carboxyl groups, a conclusion that is compatible with the reported three-dimensional structure and with the dependence of the reaction of ionic stength. 4. Very similar results were obtained with the enzymes from B. stearothermophilus and from ox muscle and ox liver, supporting the view that the ion-pair involving lysine-306 and aspartic acid-241 will be a common structural feature in glyceraldehyde-3-phosphate dehydrogenases. The B. stearothermophilus enzyme was fully active after modification. 5. No differences could be detected between the enzymes from ox muscle and ox liver, in accord with other evidence that points to the identify of these enzymes. 6. The pattern of slowly reacting amino groups in the enzyme from B. stearothermophilus, although similar to that of the mammalian enzymes, indicated one or two additional intramolecular ionic interactions of lysine residues that might contribute to the thermal stability of this enzyme.

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