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4. Methods for lithium-based battery energy storage SOC estimation

Author

Hallmann, M., Wenge, Christoph, Komarnicki, P., Balischewski, Stephan, and Publica

Subjects
equivalent circuit, simulation, battery modeling, estimation algorithm
Abstract

The use of lithium-ion battery energy storage (BES) has grown rapidly during the past year for both mobile and stationary applications. For mobile applications, BES units are used in the range of 10-120 kWh. Power grid applications of BES are characterized by much higher capacities (range of MWh) and this area particularly has great potential regarding the expected energy system transition in the next years. The optimal operation of BES by an energy storage management system is usually predictive and based strongly on the knowledge about the state of charge (SOC) of the battery. The SOC depends on many factors (e.g. material, electrical and thermal state of the battery), so that an accurate assessment of the battery SOC is complex. The SOC intermediate prediction methods are based on the battery models. The modeling of BES is divided into three types: fundamental (based on material issues), electrical equivalent circuit (based on electrical modeling) and balancing (based on a reservoir model). Each of these models requires parameterization based on measurements of input/output parameters. These models are used for SOC modelbased calculation and in battery system simulation for optimal battery sizing and planning. Empirical SOC assessment methods currently remain the most popular because they allow practical application, but the accuracy of the assessment, which is the key factor for optimal operation, must also be strongly considered. This scientific contribution is divided into two papers. Paper part I will present a holistic overview of the main methods of SOC assessment. Physical measurement methods, battery modeling and the methodology of using the model as a digital twin of a battery are addressed and discussed. Furthermore, adaptive methods and methods of artificial intelligence, which are important for the SOC calculation, are presented. In paper part II, examples of the application areas are presented and their accuracy is discussed.

Published
2022

5. Methods for lithium-based battery energy storage SOC estimation. Part II: Application and accuracy

Author

Hallmann, M., Wenge, Christoph, Komarnicki, P., and Publica

Subjects
lithium-ion battery energy storage, introduction, state of charge (SOC), equivalent circuit, battery modeling and simulation, estimation algorithm
Abstract

Climate change is driving the transformation of energy systems from fossil to renewable energies. In industry, power supply systems and electro-mobility, the need for electrical energy storage is rising sharply. Lithium-based batteries are one of the most widely used technologies. Operating parameters must be determined to control the storage system within the approved operating limits. Operating outside the limits, i.e., exceeding or falling below the permitted cell voltage, can lead to faster aging or destruction of the cell. Accurate cell information is required for optimal and efficient system operation. The key is high-precision measurements, sufficiently accurate battery cell and system models, and efficient control algorithms. Increasing demands on the efficiency and dynamics of better systems require a high degree of accuracy in determining the state of health and state of charge (SOC). These scientific contributions to the above topics are divided into two parts. In the first part of the paper, a holistic overview of the main SOC assessment methods is given. Physical measurement methods, battery modeling, and the methodology of using the model as a digital twin of a battery are addressed and discussed. In addition, adaptive methods and artificial intelligence methods that are important for SOC calculation are presented. Part two of the paper presents examples of the application areas and discusses their accuracy.

Published
2022

8. CASTALIA : A mission to a main belt comet

Author

Jones, G. H., Altwegg, K., Bertini, I., Bieler, A., Boehnhardt, H., Bowles, N., Braukhane, A., Capria, M., T., Coates, A. J., Ciarletti, Valérie, Davidsson, B., Engrand, Cécile, Fitzsimmons, A., Gibbings, A., Hainaut, O., Hallmann, M., Herique, Alain, Hilchenbach, M., Homeister, M., Hsieh, H., Jehin, E., Kofman, W., Lara, L. M., Licandro, J., Lowry, S.C., Moreno, F., Muinonen, Karri, Paetzold, M., Penttilä, Antti, Plettmeier, Dirk, Prialnik, D., Marboeuf, U., Marzari, F., Meech, Karen J., Rotundi, A., Smith, A., Snodgrass, C., Thomas, I., Trieloff, M., Mullard Space Science Laboratory (MSSL), University College of London [London] (UCL), Physikalisches Institut [Bern], Universität Bern [Bern], Centro di Ateneo di Studi e Attività Spaziali 'Giuseppe Colombo' (CISAS), Universita degli Studi di Padova, Department of Atmospheric, Oceanic, and Space Sciences [Ann Arbor] (AOSS), University of Michigan [Ann Arbor], University of Michigan System-University of Michigan System, Max-Planck-Institut für Sonnensystemforschung (MPS), Max-Planck-Gesellschaft, Department of Atmospheric, Oceanic and Planetary Physics [Oxford] (AOPP), University of Oxford [Oxford], DLR Institute of Space Systems, German Aerospace Center (DLR), Istituto di Astrofisica e Planetologia Spaziali - INAF (IAPS), Istituto Nazionale di Astrofisica (INAF), PLANETO - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Department of Physics and Astronomy [Uppsala], Uppsala University, Centre de Spectrométrie Nucléaire et de Spectrométrie de Masse (CSNSM), Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11), Astrophysics Research Centre [Belfast] (ARC), Queen's University [Belfast] (QUB), Department of Mechanical and Aerospace Engineering [Univ Strathclyde], University of Strathclyde [Glasgow], European Southern Observatory (ESO), Institut de Planétologie et d'Astrophysique de Grenoble (IPAG ), Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Observatoire des Sciences de l'Univers de Grenoble (OSUG), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS), OHB Systems AG, Institute for Astronomy [Honolulu], University of Hawai‘i [Mānoa] (UHM), Academia Sinica Institute of Astronomy and Astrophysics (ASIAA), Academia Sinica, Institut d'Astrophysique et de Géophysique [Liège], Université de Liège, Instituto de Astrofísica de Andalucía (IAA), Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), Instituto de Astrofisica de Canarias (IAC), Centre for Astrophysics and Planetary Science [Canterbury] (CAPS), University of Kent [Canterbury], Department of Physics [Helsinki], Falculty of Science [Helsinki], University of Helsinki-University of Helsinki, Universität zu Köln, Helsinki Institute of Physics (HIP), University of Helsinki, Technische Universität Dresden = Dresden University of Technology (TU Dresden), Tel Aviv University [Tel Aviv], Istituto Nazionale di Fisica Nucleare, Sezione di Padova (INFN, Sezione di Padova), Istituto Nazionale di Fisica Nucleare (INFN), Universita degli studi di Napoli 'Parthenope' [Napoli], The Open University [Milton Keynes] (OU), Universität Heidelberg [Heidelberg], IMPEC - LATMOS, Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Department of Mechanical and Aerospace Engineering [Glasgow], University of Strathclyde, Institut de Planétologie et d'Astrophysique de Grenoble (IPAG), Centre National d'Études Spatiales [Toulouse] (CNES)-Université Grenoble Alpes (UGA)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers de Grenoble (OSUG), Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS), Consejo Superior de Investigaciones Científicas [Spain] (CSIC), Technische Universität Dresden (TUD), National Institute for Nuclear Physics (INFN), Cardon, Catherine, Universität Bern [Bern] (UNIBE), Università degli Studi di Padova = University of Padua (Unipd), Max-Planck-Institut für Sonnensystemforschung = Max Planck Institute for Solar System Research (MPS), University of Oxford, Observatoire des Sciences de l'Univers de Grenoble (OSUG), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), Orbitale Hochtechnologie Bremen (OHB Systems AG), Helsingin yliopisto = Helsingfors universitet = University of Helsinki-Helsingin yliopisto = Helsingfors universitet = University of Helsinki, Universität zu Köln = University of Cologne, Helsingin yliopisto = Helsingfors universitet = University of Helsinki, Tel Aviv University (TAU), Università degli Studi di Napoli 'Parthenope' = University of Naples (PARTHENOPE), Universität Heidelberg [Heidelberg] = Heidelberg University, Mullard Space Science Laboratory ( MSSL ), University College of London [London] ( UCL ), Centro di Ateneo di Studi e Attività Spaziali 'Giuseppe Colombo' ( CISAS ), Universita degli Studi di Padova = University of Padua = Université de Padoue, Department of Atmospheric, Oceanic, and Space Sciences [Ann Arbor] ( AOSS ), Max-Planck-Institut für Sonnensystemforschung ( MPS ), Department of Atmospheric, Oceanic and Planetary Physics [Oxford] ( AOPP ), German Aerospace Center ( DLR ), Istituto di Astrofisica e Planetologia Spaziali ( IAPS ), Istituto Nazionale di Astrofisica ( INAF ), Laboratoire Atmosphères, Milieux, Observations Spatiales ( LATMOS ), Université de Versailles Saint-Quentin-en-Yvelines ( UVSQ ) -Université Pierre et Marie Curie - Paris 6 ( UPMC ) -Institut national des sciences de l'Univers ( INSU - CNRS ) -Centre National de la Recherche Scientifique ( CNRS ) -Université de Versailles Saint-Quentin-en-Yvelines ( UVSQ ) -Université Pierre et Marie Curie - Paris 6 ( UPMC ) -Institut national des sciences de l'Univers ( INSU - CNRS ) -Centre National de la Recherche Scientifique ( CNRS ), Centre de Spectrométrie Nucléaire et de Spectrométrie de Masse ( CSNSM ), Université Paris-Sud - Paris 11 ( UP11 ) -Institut National de Physique Nucléaire et de Physique des Particules du CNRS ( IN2P3 ) -Centre National de la Recherche Scientifique ( CNRS ), Astrophysics Research Centre [Belfast] ( ARC ), Queen's University [Belfast] ( QUB ), European Southern Observatory ( ESO ), Institut de Planétologie et d'Astrophysique de Grenoble ( IPAG ), Observatoire des Sciences de l'Univers de Grenoble ( OSUG ), Université Joseph Fourier - Grenoble 1 ( UJF ) -Institut national des sciences de l'Univers ( INSU - CNRS ) -Centre National de la Recherche Scientifique ( CNRS ) -Université Grenoble Alpes ( UGA ) -Université Joseph Fourier - Grenoble 1 ( UJF ) -Institut national des sciences de l'Univers ( INSU - CNRS ) -Centre National de la Recherche Scientifique ( CNRS ) -Université Grenoble Alpes ( UGA ) -Centre National de la Recherche Scientifique ( CNRS ), University of Hawaii at Manoa ( UHM ), Institute of Astronomy and Astrophysics [Taipei] ( ASIAA ), Instituto de Astrofísica de Andalucía ( IAA ), Consejo Superior de Investigaciones Científicas [Spain] ( CSIC ), Instituto de Astrofisica de Canarias ( IAC ), Centre for Astrophysics and Planetary Science [Canterbury] ( CAPS ), University of Helsinki [Helsinki], Helsinki Institute of Physics ( HIP ), Technische Universität Dresden ( TUD ), Istituto Nazionale di Fisica Nucleare, Sezione di Padova ( INFN, Sezione di Padova ), National Institute for Nuclear Physics ( INFN ), and The Open University [Milton Keynes] ( OU )

Subjects
[SDU.ASTR.EP]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], [SDU.ASTR.EP] Sciences of the Universe [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], [ SDU.ASTR.EP ] Sciences of the Universe [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP]
Abstract

International audience; Main Belt Comets (MBCs), a type of Active Asteroid , constitute a newly identified class of solar system objects. They have stable, asteroid-like orbits and some exhibit a recurrent comet-like appearance. It is believed that they survived the age of the solar system in a dormant state and that their current ice sublimation driven activity only began recently. Buried water ice is the only volatile expected to survive under an insulating surface. Excavation by an impact can expose the ice and trigger the start of MBC activity. We present the case for a mission to one of these objects, to be submitted to the European Space Agency's current call for an M-class mission. The specific science goals of the Castalia mission are: 1. Characterize a new Solar System family, the MBCs, by in-situ investigation 2. Understand the physics of activity on MBCs 3. Directly sample water in the asteroid belt and test if MBCs are a viable source for Earth's water 4. Use the observed structure of an MBC as a tracer of planetary system formation and evolution.

Published
2015

9. Riociguat for the treatment of pulmonary arterial hypertension

Author

Ghofrani, Ha, Galiè, N, Grimminger, F, Grünig, E, Humbert, M, Jing, Zc, Keogh, Am, Langleben, D, Kilama, Mo, Fritsch, A, Neuser, D, Rubin, Lj, 1 Study Group including Bortman G, Patent, Keogh, A, Kermeen, F, Feenstra, J, Williams, T, Reeves, G, Kilpatrick, D, Lang, I, Kahler, C, Mascherbauer Steringer, R, Vachiery, Jl, Delcroix, M, Meyer, G, Arakaki, J, Santana, M, Waetge, D, Granton, J, Helmersen, D, He, J, Jing, Z, Zhou, D, Huang, Y, Wang, C, Jansa, P, Neilsen Kudsk JE, Hachulla, E, De Groote, P, Frachon, I, Bourdin, A, Pison, C, Bauer, F, Dromer, C, Marquette, Ch, Degano, B, Neurohr, C, Wilkens, H, Hoffken, G, Hoeper, M, Ghofrani, A, Wirtz, H, Rosenkranz, S, Ewert, R, Orfanos, S, Kramer, M, Ben Gal, T, Scelsi, L, Vizza, C, Harari, S, Confalonieri, M, Albera, Carlo, Fukumoto, Y, Sano, M, Hatano, M, Saji, T, Tanaka, S, Takeda, Y, Takehara, K, Matsubara, H, Kihara, Y, Shiohira, Y, Kawai, H, Homma, S, Satoh, T, Tokunaga, T, Ishizaki, T, Diaz, C, Zamudio, T, De Los Rios, M, Estupian, S, Cacho, Jr, Gamba, M, Beckert, L, Torbicki, A, Castro, G, Reis, A, Agapito, A, Martins, S, Kim, H, Lee, S, Chang, H, Song, Y, Chazova, I, Moiseeva, O, Lim, S, Yip, J, Barbera, J, Roman, A, Palma Jdel, C, Reitan, O, Soderberg, S, Jansson, K, Speich, R, Hsu, Hh, Lin, Hy, Cheng, Cc, Phrommintikul, A, Jaimchariyatam, N, Sayin, T, Kultursay, H, Ongen, G, Pepke Zaba, J, Coghlan, G, Peacock, A, Gibbs, J, Wagoner, L, Badesch, D, Frost, A, Hill, N, Allen, R, Waxman, A, Sood, N, Torres, F, Minai, O, Shapiro, S, Klinger, J, Engel, P, Garcia, H, Schuller, D, Poch, D, Rosenzweig, E, Mcconnell, J, Rischard, F, Olschewski, H, Haverkamp, W, Lehmacher, W, Hoischen, S, Collamati, S, Dehay, J, Hallmann, M, Menezes, F., Ghofrani HA, Galiè N, Grimminger F, Grünig E, Humbert M, Jing ZC, Keogh AM, Langleben D, Kilama MO, Fritsch A, Neuser D, Rubin LJ, and PATENT-1 Study Group

Subjects
medicine.medical_specialty, business.industry, General Medicine, Placebo, medicine.disease, Pulmonary hypertension, Riociguat, law.invention, Surgery, Clinical trial, chemistry.chemical_compound, medicine.anatomical_structure, Randomized controlled trial, chemistry, DRUG THERAPY, law, Anesthesia, riociguat, pulmonary arterial hypertension, Clinical endpoint, Vascular resistance, Medicine, business, Macitentan, medicine.drug
Abstract

Riociguat, a soluble guanylate cyclase stimulator, has been shown in a phase 2 trial to be beneficial in the treatment of pulmonary arterial hypertension. METHODS: In this phase 3, double-blind study, we randomly assigned 443 patients with symptomatic pulmonary arterial hypertension to receive placebo, riociguat in individually adjusted doses of up to 2.5 mg three times daily (2.5 mg-maximum group), or riociguat in individually adjusted doses that were capped at 1.5 mg three times daily (1.5 mg-maximum group). The 1.5 mg-maximum group was included for exploratory purposes, and the data from that group were analyzed descriptively. Patients who were receiving no other treatment for pulmonary arterial hypertension and patients who were receiving endothelin-receptor antagonists or (nonintravenous) prostanoids were eligible. The primary end point was the change from baseline to the end of week 12 in the distance walked in 6 minutes. Secondary end points included the change in pulmonary vascular resistance, N-terminal pro-brain natriuretic peptide (NT-proBNP) levels, World Health Organization (WHO) functional class, time to clinical worsening, score on the Borg dyspnea scale, quality-of-life variables, and safety. RESULTS: By week 12, the 6-minute walk distance had increased by a mean of 30 m in the 2.5 mg-maximum group and had decreased by a mean of 6 m in the placebo group (least-squares mean difference, 36 m; 95% confidence interval, 20 to 52; P

Published
2013

10. AsteroidFinder - a German Mission for the Search of IEOs

Author

Kührt, E., Mottola, S., Spietz, P., Behrens, J., Gerene, S., Grundmann, J.T., Hahn, G., Hallmann, M., Messina, G., Michaelis, H., and Scheibe, K.

Subjects
asteroids, space debris, space mission, IEOs
Published
2009

13. Hybrid Tolerance Representation of Systems in Motion.

Author

Heling, B., Hallmann, M., and Wartzack, S.

Abstract

Dimensional management deals with the fact that the real geometry of every manufactured part deviates from its ideal shape. To evaluate the effects of these deviations tolerance analysis, which are often based on vectorial models, are carried out. Nevertheless the use of vectorial models has one major disadvantage – they cannot adequately represent form deviations. As a consequence new concepts of representations based on the GPS’ Skin Model have been established. Since the use of Skin Model Shapes (SMS) is time-consuming and does not always offer advantages over vectorial models, the Hybrid Tolerance Representation (HTR) which combines the advantages of vectorial and discretely represented tolerances is introduced in this paper. The HTR is based on a classification of the contact situation of the cinematic chain into lower and higher kinematic pairs. Based in this classification all higher kinematic pairs are going to be represented by SMS whereas lower pairs, are represented by vectors. Besides the simulation of the contact situation of all higher kinematic pairs the coupling of vectorial and discrete geometry representations is a challenge. The practical implementation of the presented method is shown on an X-ray shutter. [ABSTRACT FROM AUTHOR]

Published
2016
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15. A New Eulerian Model for Turbulent Evaporating Sprays in Recirculating Flows

Author

Wittig, S. (author), Hallmann, M. (author), Scheurlen, M. (author), Schmehl, R. (author), Wittig, S. (author), Hallmann, M. (author), Scheurlen, M. (author), and Schmehl, R. (author)

Abstract

A new Eulerian model for the computation of turbulent evaporating sprays in recirculating flows is derived. It comprises droplet heating and evaporation processes by solving separate transport equations for the droplet's temperature and diameter. Full coupling of the droplet and the gaseous phase is achieved by the exchange of source terms due to momentum, heat and mass transfer. The partial differential equations describing the droplet's transport and evaporation in the new method can be solved using the same numerical procedure as for the gas phase equations. The validity of the model is established by comparison with a well known Lagrangian approach and with experimental data. For this purpose calculations of a recirculating droplet charged air flow within a model combustor are presented., Aerospace Engineering

Published
1993

24. [The global medical network Education Against Tobacco-voluntary tobacco prevention made in Germany].

Author

Brinker TJ, Buslaff F, Haney C, Gaim B, Haney AC, Schmidt SM, Silchmüller MP, Taha L, Jakob L, Baumert HM, Hallmann M, Heckl M, Alfitian J, Brieske CM, Divizieva EP, Wilhelm J, Hillebrand G, Penka D, Raveendranathan S, and Suhre JL

Subjects
Adolescent, Child, Female, Germany, Humans, Male, Prospective Studies, Randomized Controlled Trials as Topic, Students, Smoking Cessation, Smoking Prevention, Nicotiana
Abstract

Smoking is the leading preventable cause of premature death in Germany. The network "Education Against Tobacco" (EAT) is an initiative that was founded in Germany in 2012, in which more than 3500 medical students and physicians engage in volunteer work in about 80 medical faculties in 14 countries. In this article, the concept, activities, objectives and associated research studies oft he EAT initiative are introduced.On the school level, the initiative addresses 10- to 15-year-old secondary school students. In addition to a multimodal approach, school visits use modern media such as facemorphing apps, which are not only used by students (45,000 per year in 14 countries), but by a total of over 500,000 other people as well. The effectiveness of the school-based intervention is currently being investigated in randomised long-term studies with 20,000 adolescents in Germany. A first long-term study demonstrated evidence of a protective effect regarding the onset of smoking, especially among female students, students having a low level of education and students with a migratory background.The programme educates several hundred prospective physicians at 13 (of 28 participating) German medical faculties each year in science-based elective courses for the well-established smoking cessation counselling of patients and sensitises them to the tobacco epidemic. The approved members engage in dialogue with local members of the German house of representatives as "Ärzteverband Tabakprävention".EAT motivates the prospective generation of physicians, initially through prevention in school settings, to face the challenge of national tobacco control at the university and federal level.

Published
2018
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25. Quantum-chemical studies on the favored and rare tautomers of neutral and redox adenine.

Author

Raczyńska ED, Makowski M, Zientara-Rytter K, Kolczyńska K, Stępniewski TM, and Hallmann M

Subjects
DNA chemistry, Isomerism, Molecular Structure, Oxidation-Reduction, Phase Transition, Water chemistry, Adenine chemistry, Quantum Theory
Abstract

All possible twenty-three prototropic tautomers of neutral and redox adenine (nine amine and fourteen imine forms, including geometric isomerism of the exo ═NH group) were examined in vacuo {DFT(B3LYP)/6-311+G(d,p)}. The NH → NH conversions as well as those usually omitted, NH → CH and CH → CH, were considered. An interesting change of the tautomeric preference occurs when proceeding from neutral to reduced adenine. One-electron reduction favors the nonaromatic amine C8H-N10H tautomer. This tautomeric preference is similar to that (C2H) for reduced imidazole. Water molecules (PCM model) seem to not change this trend. They influence solely the relative energies. The DFT vertical detachment energy in the gas phase is positive for each tautomer, e.g., 0.03 eV for N9H-N10H and 1.84 eV for C8H-N10H. The DFT adiabatic electron affinity for the favored process, neutral N9H-N10H → reduced C8H-N10H (ground states), is equal to 0.18 eV at 0 K (ZPE included). One-electron oxidation does not change the tautomeric preference in the gas phase. The aromatic amine N9H-N10H tautomer is favored for the oxidized molecule similarly as for the neutral one. The DFT adiabatic ionization potential for the favored process, neutral N9H-N10H → oxidized N9H-N10H (ground states), is equal to 8.12 eV at 0 K (ZPE included). Water molecules (PCM model) seem to influence solely the composition of the tautomeric mixture and the relative energies. They change the energies of the oxidation and reduction processes by ca. 2 eV.

Published
2013
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