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Academic literature on the topic 'Energetics - Theoretical Study'

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Published: 7 September 2023

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Journal articles on the topic "Energetics - Theoretical Study"

SHOUCRI, Rachad M. "Theoretical Study Related to Left Ventricular Energetics." Japanese Heart Journal 34, no. 4 (1993): 403–17. http://dx.doi.org/10.1536/ihj.34.403.

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Takeuchi, Jo, and Kyozaburo Takeda. "Theoretical Study on Proton Transfer and Energetics in Ammonium Nitrate (NH4NO3)n Cluster System." International Journal of Applied Physics and Mathematics 4, no. 1 (2014): 5–8. http://dx.doi.org/10.7763/ijapm.2014.v4.245.

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Fengyou, Hao, Zhao Yongfang, Jing Xiaogong, Li Xinying, and Liu Fengli. "Theoretical study on structures and energetics of Ge2P2." Journal of Molecular Structure: THEOCHEM 764, no. 1-3 (May 2006): 47–52. http://dx.doi.org/10.1016/j.theochem.2006.02.002.

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Sohn, Woon Yong, Tae Wu Kim, and Jae Shin Lee. "Structure and Energetics of C60O: A Theoretical Study." Journal of Physical Chemistry A 114, no. 4 (February 4, 2010): 1939–43. http://dx.doi.org/10.1021/jp9093386.

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Assadi, M. Hussein N., and Dorian A. H. Hanaor. "Theoretical study on copper's energetics and magnetism in TiO2 polymorphs." Journal of Applied Physics 113, no. 23 (June 21, 2013): 233913. http://dx.doi.org/10.1063/1.4811539.

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Deakyne, C. A., D. M. Knuth, M. Meot-Ner, C. M. Breneman, and J. F. Liebman. "Experimental and theoretical study of the energetics of trialkylsulfonium ions." Journal of Molecular Structure 485-486 (August 1999): 33–41. http://dx.doi.org/10.1016/s0022-2860(99)00040-x.

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Alamanova, Denitsa, Valeri G. Grigoryan, and Michael Springborg. "Theoretical Study of the Structure and Energetics of Silver Clusters." Journal of Physical Chemistry C 111, no. 34 (August 2007): 12577–87. http://dx.doi.org/10.1021/jp0717342.

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Galland, Nicolas, Yacine Hannachi, Dominick V. Lanzisera, and Lester Andrews. "Theoretical study of structures, energetics and vibrational properties of BC2H5 species." Chemical Physics 255, no. 2-3 (May 2000): 205–15. http://dx.doi.org/10.1016/s0301-0104(00)00091-4.

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Lintuluoto, M. "Theoretical study on the structure and energetics of alkali halide clusters." Journal of Molecular Structure: THEOCHEM 540, no. 1-3 (May 2001): 177–92. http://dx.doi.org/10.1016/s0166-1280(00)00741-7.

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Galland, Nicolas, Yacine Hannachi, Dominick V. Lanzisera, and Lester Andrews. "Theoretical study of structures, energetics and vibrational properties of BC2H3 species." Chemical Physics 230, no. 2-3 (May 1998): 143–51. http://dx.doi.org/10.1016/s0301-0104(98)00050-0.

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Dissertations / Theses on the topic "Energetics - Theoretical Study"

Gonzalez, Ines M. "THEORETICAL STUDY OF THE STRUCTURES AND ENERGETICS OF AROMATIC CLUSTERS: DEVELOPMENT OF RELIABLE AND PRACTICAL THEORETICAL MODELS FOR INTERMOLECULAR POTENTIALS." University of Akron / OhioLINK, 2006. http://rave.ohiolink.edu/etdc/view?acc_num=akron1164652307.

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Agapito, Filipe Miguel Peres 1981. "Theoretical study of the reactivity and energetics of organic radicals." Doctoral thesis, 2010. http://hdl.handle.net/10451/1835.

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Tese de doutoramento, Química (Química Física), 2010, Universidade de Lisboa, Faculdade de Ciências
Os radicais orgânicos são espécies importantes em quase todos os domínios daquímica e bioquímica. Contudo, apesar da sua existência ter sido documentadahá mais de uma centena de anos, uma fracção significativa da energéticadestas espécies é ainda desconhecida. Uma propriedade termoquímica crucialno estudo de um radical é a entalpia associada à quebra da ligação (BDE)que dá origem a esse radical. Estas BDEs podem ser obtidas experimentalmenteatravés de calorimetria fotoacústica (PAC). A química computacionaltambém pode ser utilizada para fazer previsões rigorosas desta propriedade termoquímica.Os métodos teóricos permitem ainda o acesso directo à estruturade radicais e compostos pais. Neste trabalho, PAC e química computacionalforam utilizadas conjuntamente para estudar a energética de radicais orgânicos.A entalpia de formação padrão do radical ciclopentadienilo e a BDE C H parao 1,3-ciclopentadieno foram reexaminadas. Foi avaliada a precisão de extrapolaçõespara base completa de CCSD(T) e a de métodos de optimização com basena teoria do funcional da densidade. De seguida foi efectuado um estudo detalhadoda energética do grupo alilo. Finalmente, foi estudado o efeito da tensãode anel em hidrocarbonetos cíclicos com cinco e seis membros e respectivosradicais.
Organic radicals are important species in virtually every domain of chemistryand biochemistry. However, even though they have been known for morethan 100 years, the energetic data for radicals typically have large uncertaintiesor are missing. One crucial thermochemical property in the study of a radicalis the enthalpy associated with the bond cleavage (BDE) which originates thatradical. BDEs can be obtained experimentally with photoacoustic calorimetry(PAC). Computational chemistry also provides reliable estimates of thisthermochemical property. In addition, theoretical methods provide direct accessto the structure of radicals and their parent compounds. In this work bothPAC and computational chemistry were used to study the energetics of organicradicals. The standard enthalpy of formation for the cyclopentadienyl radicaland the 1,3-cyclopentadienyl C H BDE were re-examined. We proceeded toassess the accuracy of cost-efficient CCSD(T) complete basis set extrapolationschemes and density functional theory optimization methods for radicals. Adetailed analysis of the energetics of the allyl moiety was then conducted. Finally,the effect of ring strain on five- and six-membered ring hydrocarbons andrespective radicals was discussed.

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"Theoretical study of the structures, energetics and reactions of some chemical systems." 2005. http://library.cuhk.edu.hk/record=b5892564.

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Lam Chow Shing.
Thesis (M.Phil.)--Chinese University of Hong Kong, 2005.
Includes bibliographical references.
Abstracts in English and Chinese.
Thesis Examination Committee --- p.i
Abstract --- p.ii
Acknowledgements --- p.iv
Table of Contents --- p.v
List of Tables --- p.vii
List of Figures --- p.viii
Chapter Chapter 1 --- Introduction --- p.1
Chapter 1.1 --- The Gaussian-3 Method --- p.1
Chapter 1.2 --- The G3 Method with Reduced MΦller- Plesset Order and Basis Set --- p.2
Chapter 1.3 --- Density Functional Theory (DFT) --- p.3
Chapter 1.4 --- Calculation of Thermodynamical Data --- p.3
Chapter 1.5 --- Remark on the Location of Transition Structures --- p.3
Chapter 1.6 --- Natural Bond Orbital (NBO) Analysis --- p.4
Chapter 1.7 --- Scope of the Thesis --- p.4
Chapter 1.8 --- References --- p.5
Chapter Chapter 2 --- Theoretical Study of Tri-s-triazine and Its Derivatives --- p.7
Chapter 2.1 --- Introduction --- p.7
Chapter 2.2 --- Methods of Calculation --- p.9
Chapter 2.3 --- Results and Discussion --- p.9
Chapter 2.3.1. --- Property of Tri-s-triazine --- p.9
Chapter 2.3.2. --- Substituent Effects on the Properties of the Tri-s-triazine Parent Molecule --- p.10
Chapter 2.3.3. --- Heats of Formation of Derivatives of Tri-s-triazine --- p.20
Chapter 2.4 --- Conclusion --- p.22
Chapter 2.5 --- References --- p.22
Chapter Chapter 3 --- A Gaussian-3 Study of the Dissociative Photoionization of Acetone --- p.25
Chapter 3.1 --- Introduction --- p.25
Chapter 3.2 --- Methods of Calculation --- p.26
Chapter 3.3 --- Results and Discussion --- p.26
Chapter 3.3.1. --- "Formation of m/z = 42 (CH2CO+.),43 (CH3CO+) Ions" --- p.31
Chapter 3.3.2. --- Formation of m/z = 43 (c-CH2CHO+) and m/z = 15 (CH3+) Ions --- p.32
Chapter 3.3.3. --- Formation of m/z = 57 (CH3COCH2+) Ions --- p.37
Chapter 3.3.4. --- Formation of m/z = 39 (C3H3+) Ions --- p.38
Chapter 3.4 --- Conclusion --- p.40
Chapter 3.5 --- Publication Note --- p.40
Chapter 3.6 --- References --- p.40
Chapter Chapter 4 --- "A G3(MP2) Study of the C3H60+. Isomers Fragmented from l,4-Dioxane+" --- p.42
Chapter 4.1 --- Introduction --- p.42
Chapter 4.2 --- Methods of Calculation --- p.43
Chapter 4.3 --- Results and Discussion --- p.44
Chapter 4.3.1. --- "Formation of C3H60+. Isomers 1 and 2 via Fragmentation of 1,4-Dioxane+" --- p.44
Chapter 4.3.2. --- Reaction with Acetonitrile --- p.55
Chapter 4.3.3. --- Reaction with Formaldehyde --- p.57
Chapter 4.3.4. --- Reaction with Ethylene --- p.61
Chapter 4.3.5. --- Reaction with Propene --- p.63
Chapter 4.4 --- Conclusion --- p.67
Chapter 4.5 --- Publication Note --- p.68
Chapter 4.6 --- References --- p.68
Chapter Chapter 5 --- A Computational Study of the Photodissociation Channels of Chloroiodomethane --- p.71
Chapter 5.1 --- Introduction --- p.71
Chapter 5.2 --- Methods of Calculation --- p.73
Chapter 5.3 --- Results and Discussion --- p.74
Chapter 5.3.1 --- CH2C1 + I(2P1/2) and CH2C1 + I(2P3/2) Channels --- p.77
Chapter 5.3.2 --- "CH2I + C1(2P3/2,1/2) Channel" --- p.78
Chapter 5.3.3 --- CHI + HC1 Channel --- p.80
Chapter 5.3.4 --- CH2 + IC1 Channel --- p.81
Chapter 5.4 --- Conclusion --- p.82
Chapter 5.5 --- Publication Note --- p.83
Chapter 5.6 --- References --- p.83
Chapter Chapter 6 --- Conclusion --- p.86
Appendix A --- p.87
Appendix B --- p.89

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Al-Khodaier, Mohannad. "Energetic Molecules as Future Octane Boosters: Theoretical and Experimental Study." Diss., 2018. http://hdl.handle.net/10754/630113.

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The utilization of energetic strained molecules may be one way to mitigate carbon emissions or better and more economical fuel blends. To investigate candidate molecules, limonene and dicyclopentadiene, both theoretical and experimental procedures were implemented here. Computational quantum chemistry methods were employed to determine the thermodynamic properties and kinetic parameters for the hydrogen-abstraction reactions of limonene by a hydrogen atom. Geometry optimization and energy calculation was conducted for all stable species and transition states using Gaussian 09. The rate constants of the H-abstraction reactions were calculated using conventional transition state theory, as implemented in ChemRate software. The obtained values were fitted over the temperature range of 298 – 2000 K to obtain the modified Arrhenius parameters. Increasing the anti-knock quality of gasoline fuels can enable higher efficiency in spark ignition engines. This study explores blending the anti-knock quality of dicyclopentadiene (DCPD, a by-product of ethylene production from naphtha cracking), with various gasoline fuels. The blends were tested in an ignition quality tester (IQT) and a modified cooperative fuel research (CFR) engine operating under homogenous charge compression ignition (HCCI) and knock limited spark advance (KLSA) conditions. Ethanol is widely used as a gasoline blending component in many markets, due to current fuel regulations. The test results of DCPD-gasoline blends were compared to those of ethanol-gasoline blends. Furthermore, the anti-knock properties of dicyclopentadiene (DCPD) as an additive to primary reference fuels (PRF) and toluene primary reference fuels (TPRF) have been investigated. The research octane number (RON) and motor octane number (MON) were measured using cooperative fuels research (CFR) engine for four different fuel blends. Moreover, the ignition delay times of these mixtures were measured in a high-pressure shock tube at 40 bar and stoichiometric mixtures over a temperature range of [700-1200 K]. Ignition delay measurements were also conducted using rapid compression machine (RCM) at stoichiometric conditions and 20 bar. An ignition quality tester (IQT) compared ignition delay times of iso-octane and DCPD. Furthermore, a chemical kinetic auto-ignition model was designed to simulate the IDT experiments.

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Cheng, Sou-Ro, and 鄭淑銣. "Theoretical computational study of decomposition mechanisms for highly energetic molecule GZT and its derivatives." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/36202085451423269875.

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博士
國防大學理工學院
國防科學研究所
101
In this thesis, theoretical calculations of decomposition mechanisms and thermodynamic properties for the highly energetic bis(guanidinium) 5,5'-azotetrazolate (GZT) ; and the geometry optimization of the bis(aminoguanidinium) 5,5'-azotetrazolate (AGZT) of GZT derivatives, were investigated. Base on the calculation results of ionic type decomposition patterns, GZT was initially cracked into two guanidinium cations (G+) and a 5,5'–azotetrazolate anion (ZT2-). Three routes－the elimination of a hydronium ion (H+), the elimination of a hydrogen radical (H•), and the elimination of an amino radical (•NH2)－were suggested for the decomposition of the G+ cation. The other three routes－single ring opening, double ring opening, and N–N bond cleavage of outside the ring－were proposed for the further decomposition of the ZT2- anion. Fourteen decomposition species were obtained on splitting both the cation and anion, and also successfully identified 11 G+ cation-related and 11 ZT2- anion-related decomposition transition states. In G+ cation cracking, the lowest activation energy of about 210 kJmol-1 was required, and the final products CN+ and NH3 were obtained. In ZT2- anion cracking, the lowest activation energy of about 250 kJmol-1 was required, and the final products CN– and N2 were obtained. Base on the calculation results of molecular type decomposition patterns, GZT was initiated by heterocyclic ring opening, sequential cracking of the two five-membered rings of GZT, and simultaneous release of N2 molecules; whereas proton transfer, bond-breaking, and atomic rearrangements were performed subsequently. Finally, fifteen reaction paths and five transition states were obtained. The results revealed that (1) the maximum activation energy required is 187.8 kJmol-1, and the enthalpy change (ΔH) and Gibbs free-energy change (ΔG) of the net reaction are −525.1 kJmol-1 and −935.6 kJmol-1, respectively; (2) GZT can release large amounts of energy, the main contribution being from the disintegration of the 5,5'-azotetrazolate anion (ZT2−) skeleton (ΔH=−598.3 kJmol-1); and (3) the final products contained major amounts of N2 gas, but remaining gas molecules such as HCN and NH3 were obtained. The geometry optimization of bis(aminoguanidinium) 5,5'-azotetrazolate (AGZT) of GZT derivatives was studied. The results of calculation revealed that ten stable conformers with different potential energy were obtained, and conformers were named as A1 to A10, respectively, by the order of its energy level from low to high. By using the semi-empirical INDO program “local bond population analysis” method to calculate the intramolecular hydrogen bonding, bond energy, bond order, and Columbic attraction energy of AGZT and its conformers. It can be used to explain the influences of intramolecular hydrogen bonding on the stability of AGZT conformers.

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Books on the topic "Energetics - Theoretical Study"

Yang, Jingduan, and Daniel A. Monti. Clinical Acupuncture and Ancient Chinese Medicine. Oxford University Press, 2017. http://dx.doi.org/10.1093/med/9780190210052.001.0001.

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Clinical Acupuncture and Ancient Chinese Medicine provides health care professionals interested in learning or practicing acupuncture the essential theoretical foundation of Chinese medicine on which an effective acupuncture therapy must be based. It describes in detail the human energetic anatomy, physiology, pathophysiology, and etiology for both mental and physical functions of children, men, women, and the elderly. It offers a step-by-step algorithm for diagnosing physical or mental ailments with diagnostic techniques and formulation processes and treating them with effective strategies, plans, and acupuncture techniques. Clinical Acupuncture and Ancient Chinese Medicine also presents acupuncture as an energy medicine, in contrast to modern medicine, which is a more biochemically and structurally based medicine. Both are integral parts in the spectrum of human medicine, more complementary than alternative to each other. This book helps readers to study and practice acupuncture as part of their continued medical education (CME) and as a natural expansion of their practice to provide additional care for their patients at the energetic level at which a majority of ailments lay. The content is organized in a way that parallels modern medicine so readers can more easily relate and understand concepts that may be otherwise foreign to them. This book describes human health with the belief that a human being is essentially an energetic being and that the interaction of human energy with the energy of nature and the universe is critical to maintaining a healthy life. It provides useful contents for self-care and the ancient practice of life cultivation.

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Book chapters on the topic "Energetics - Theoretical Study"

Futamura, Ryusuke, Miguel Jorge, and José R. B. Gomes. "Structures and energetics of organosilanes in the gaseous phase: a computational study." In Highlights in Theoretical Chemistry, 167–76. Berlin, Heidelberg: Springer Berlin Heidelberg, 2012. http://dx.doi.org/10.1007/978-3-642-41272-1_19.

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Puzzarini, Cristina, and Alberto Gambi. "A theoretical study on CH2N2 isomers: structure and energetics." In Vincenzo Barone, 31–40. Berlin, Heidelberg: Springer Berlin Heidelberg, 2012. http://dx.doi.org/10.1007/978-3-642-34462-6_5.

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Reames, Donald V. "Element Abundances and FIP: SEPs, Corona, and Solar Wind." In Solar Energetic Particles, 167–85. Cham: Springer International Publishing, 2021. http://dx.doi.org/10.1007/978-3-030-66402-2_8.

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AbstractWe have used abundance measurements to identify the sources and the physical processes of acceleration and transport of SEPs. Here we study energetic particles themselves as samples of the solar corona that is their origin, distinguishing the corona from the photosphere and the SEPs from the solar wind. Theoretically, differences in the first ionization potential “FIP effect” may distinguish closed- and open-field regions at the base of the corona, which may also distinguish SEPs from the solar wind. There is not a single coronal FIP effect, but two patterns, maybe three. Are there variations? What about He?

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San-Fabián, E., A. Pérez-Guardiola, M. Moral, A. J. Pérez-Jiménez, and J. C. Sancho-García. "Theoretical Study of Strained Carbon-based Nanobelts: Structural, Energetic, Electronic, and Magnetic Properties of [n]Cyclacenes." In Advanced Magnetic and Optical Materials, 165–83. Hoboken, NJ, USA: John Wiley & Sons, Inc., 2016. http://dx.doi.org/10.1002/9781119241966.ch6.

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Tossell, John A., and David J. Vaughan. "Application of Quantum-Mechanical Methods to Simple Inorganic “Molecules” of Relevance to Mineralogy, and to Oxide Minerals." In Theoretical Geochemistry. Oxford University Press, 1992. http://dx.doi.org/10.1093/oso/9780195044034.003.0006.

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As noted in the introduction to this text, much can be learned through the application of both quantum-mechanical calculations and experimental techniques to simple molecules that contain bonds of the type found in the important groups of minerals. One reason for this approach is that calculations at a higher level of quantum-mechanical rigor can be applied to such simple systems. This approach will be illustrated with reference to the SiO, SiO2, Si2O2, Si3O3, and SiF4 molecules. Attention will then be turned to the major oxide minerals MgO, Al2O3, and SiO2 and the binary transition-metal oxides of Ti, Mn, and Fe, with some brief discussion of the series of transition-metal monoxides (MnO, FeO, CoO, NiO) and complex oxides (FeCr2O4, FeTiO3, etc.), and of the problem of the calculation of Mössbauer parameters in iron oxides (and other compounds). Although silicon monoxide, SiO, is not an important component of minerals, it is an important chemical constituent in interstellar and circumstellar space and an important starting material for the gas-phase synthesis of silicates from components of the nebula (Day and Donn, 1978). The structure, energetics, and spectral properties of SiO have been calculated by a number of different methods. The Si-O bond distance calculated using ab initio Hartree-Fock-Roothaan SCF methods at the 6-31G* basis- set level is 1.487 Å (Snyder and Raghavachari, 1984), slightly smaller than the experimental value of 1.5097 Å (Field et al., 1976). A near Hartree- Fock limit basis set and limited configuration-interaction calculation has given the slightly better value of 1.496 Å (Langhoff and Arnold, 1979). This study also gave a bond dissociation energy of 8.10 eV, compared to an experimental value of 8.26 ± 0.13 eV (Hildenbrand, 1972), and a bond stretching frequency of 1248 cm- 1 , compared to an experimental value of 1242 cm-1 (Anderson and Ogden, 1969). Even more highly correlated calculations give a bond distance of 1.515 Å and a stretching frequency of 1242 cm-1 (Werner et al., 1982). The 6-31G* basis-set Hartree-Fock-Roothaan calculation also gives an almost exactly correct bond-stretching frequency after the standard correction factor describing correlation effects is applied (Hehre et al., 1986).

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Tossell, John A., and David J. Vaughan. "The Future." In Theoretical Geochemistry. Oxford University Press, 1992. http://dx.doi.org/10.1093/oso/9780195044034.003.0011.

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In this final chapter, an attempt is made to provide an overview of the capabilities of quantum-mechanical methods at the present time, and to highlight the needs for future development and possible future applications of these methods, particularly in areas related to mineral structures, energetics, and spectroscopy. There is also a brief account of some new areas of application, specific directions for future research, and possible developments in the perception and use of quantum-mechanical approaches. The book ends with an epilog on the overall role of “theoretical geochemistry” in the earth and environmental sciences. The local structural characteristics of minerals such as Mg2SiO4, which contain only main-group elements, are reasonably well reproduced by ab initio Hartree-Fock-Roothaan (SCF) cluster calculations at the mediumbasis- set level. Calculations incorporating configuration interaction will inevitably follow and probably lead to somewhat better agreement with experiment. The most pressing needs in this area of study are for the development of systematic procedures for cluster selection and embedding, for a greater understanding of the results at a qualitative level, and for more widespread efficient application of the quantum-chemical results currently available. In the last area, substantial progress has already been made by Lasaga and Gibbs (1987), Sanders et al. (1984), Tsuneyuki et al. (1988), and others, who have used ab initio calculations to generate theoretical force fields which can then be used in molecular-dynamics simulations. If the characteristics of the resultant force fields can be understood at a first-principles level, then it may be possible to understand details of the simulated structures at the same level. Unfortunately, as regards a greater qualitative understanding of the quantum-mechanical calculations, little progress has been made. Rather old qualitative theories describe some aspects of bond-angle variation (Tossell, 1986), but no general model to interpret variations in bond lengths has been developed within either chemistry or geochemistry beyond the model of additive atomic (Slater) or ionic (Shannon and Prewitt) radii. Indeed, global theories of bond-length variations within an ab initio framework seem to be nonexistent. Nonetheless, quantum-chemical studies have shown the presence of intriguing systematics in bond lengths (Gibbs et al., 1987), which had been already noted empirically.

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Scheiner, Steve. "The Nature of the Hydrogen Bond, from a Theoretical Perspective." In Intermolecular Interactions in Crystals: Fundamentals of Crystal Engineering, 410–52. The Royal Society of Chemistry, 2017. http://dx.doi.org/10.1039/bk9781782621737-00410.

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The original concept of the H-bond has undergone a good deal of generalization over the years to include a wide range of proton donor atoms and electron-donor sources. The means by which theoreticians study and understand the fundamental aspects of H-bonds are discussed, including various techniques that focus upon energetics, electrostatic potentials, charge transfer, electron density patterns, and spectroscopic features. In order to provide concrete examples of these methods, the chapter focuses on H-bonds in which C serves as proton-donor atom, a type of interaction which was not hitherto considered as an H-bond. The discussion ranges from very small systems to those with biological relevance. The sensitivity of H-bond strength to stretching and bending is critically examined as are the effects of placing a charge on one or both of the subunits.

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Balny, Claude. "Transient Enzyme Kinetics at High Pressure." In High Pressure Effects in Molecular Biophysics and Enzymology. Oxford University Press, 1996. http://dx.doi.org/10.1093/oso/9780195097221.003.0017.

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In a detailed study of an enzyme reaction pathway, a measured composite rate constant, for example, kcat, can be interpreted in ways that lead to ambiguous conclusions. Two conditions must be met to solve this problem: (1) an elementary rate constant must be measured, and (2) a maximum number of physical-chemical parameters must be used to perturb the system under study. To gain access to elementary rate constants, cryobaroenzymology and/or transient methods, such as stopped-flow and flow-quench kinetics, can be used. Both perturbation and kinetics measurements performed under either high pressure or low temperatures can then be used to probe the thermodynamics of the interconversion of two successive intermediates to obtain parameters such as ΔG‡, ΔS‡, ΔH‡, and ΔV‡ The interdependence of the two major variables, namely temperature and pressure, is presented in this article, in which the role of organic cosolvents is considered as a third variable. During catalytic reactions, enzymes undergo a number of conformational changes related to their dynamic structural flexibility. This appears as a succession of different steps. A complete study of such processes, which generally are very rapid, consists of the exploration of the properties of these steps, including thermodynamic features obtained by the action of temperature and pressure. As long ago as 1950, Laidler (1950) formulated the first theoretical basis for explaining the responses of enzymes to high hydrostatic pressures. Chemists used this parameter extensively, and in the early stages of high-pressure kinetics they attempted to analyze the observed results on the basis of collision theory (Asano, 1991) or transition-state theory (Evans & Polanyi, 1935). These theories are still used to describe pressure effects on enzyme reactions. It is postulated that between two successive intermediates there is a labile transition state which governs the energetics of the reaction (Glastone et al., 1941). But we must remember that this theory was first applied only to simple homogeneous reactions in gases. For solutions, the treatment can require the introduction of other parameters such as the viscosity.

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Bujalowski, Wlodzimierz, and Maria J. Jezewska. "Quantitative determination of equilibrium binding isotherms for multiple ligand-macromolecule interactions using spectroscopic methods." In Spectrophotometry and Spectrofluorimetry. Oxford University Press, 2000. http://dx.doi.org/10.1093/oso/9780199638130.003.0009.

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Thermodynamic studies provide information that is necessary in order to understand the forces that drive the formation of ligand-macromolecule complexes. Knowledge of the energetics of these interactions is also indispensable for characterization of functionally important structural changes that occur within the studied complexes. Quantitative examination of the equilibrium interactions are designed to provide the answers to the questions: What is the stoichiometry of the formed complexes? How strong or how specific are the interactions? Are there any cooperative interactions among the binding sites and/or the bound ligand molecules? Are the binding sites intrinsically heterogeneous? What are the molecular forces involved in the formation of the studied complexes, or, in other words, how do the equilibrium binding and kinetic parameters depend on solution variables (temperature, pressure, pH, salt concentration, etc.)? Equilibrium isotherms for the binding of a ligand to a macromolecule represent the relationship between the degree of ligand binding (moles of ligands bound per mole of a macromolecule) and the free ligand concentration. A true thermodynamic binding isotherm is model-independent and reflects only this relationship. Only then, when such an isotherm is obtained, can one proceed to extract physically meaningful interaction parameters that characterize the free energies of interaction. This is accomplished by comparing the experimental isotherms to theoretical predictions based on specific binding models that incorporate known molecular aspects, such as intrinsic binding constants, cooperativity parameters, allosteric equilibrium constants, discrete character of the binding sites or overlap of potential binding sites, etc. (see below). Any method used to quantitatively study ligand binding to a macromolecule must relate the extent of the complex formation to the free ligand concentration in solution. Numerous techniques have been developed to study equilibrium properties of specific and non-specific ligand-macromolecule interactions in which binding is directly monitored, including equilibrium dialysis, ultrafiltration, column chromatography, filter binding assay and gel electrophoresis (1-6). These direct methods are very straightforward; however, they are usually time consuming and some, like filter binding or gel shift assays, are non-equilibrium techniques which require many controls before the reliable equilibrium binding data can be obtained.

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Kubba, Rehab Majed, and Khalida Abaid Samawi. "Theoretical Study of Bonds Length, Energetic and Vibration Frequencies for Construction Units of (6,0) ZigZag SWCNTs." In Application of Quantum Mechanical Calculations and Symmetry in Chemistry; Vibration Frequencies, Corrosion Inhibition and Prodrugs, 45–59. Book Publisher International (a part of SCIENCEDOMAIN International), 2021. http://dx.doi.org/10.9734/bpi/mono/978-93-91882-61-7/ch4.

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Conference papers on the topic "Energetics - Theoretical Study"

Hough, Jessandra, Ryan S. McGinnis, and N. C. Perkins. "Benchmarking the Accuracy of Inertial Measurement Units for Estimating Kinetic Energy." In ASME 2013 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2013. http://dx.doi.org/10.1115/imece2013-63303.

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The energetics of human motion has been intensely studied using experimental and theoretical methods. Knowing the kinetic energy of the human body, and its decomposition into the kinetic energies of the major body segments, has tremendous value in applications ranging from physical therapy, athlete training, soldier performance, worker health and safety, among other uses. Significant challenges thwart our ability to measure segmental kinetic energy in real (non-laboratory) environments such as in the home or workplace, or on the playing/training field. The aim of this research is to address these challenges by advancing the use of an array of miniaturized body-worn inertial measurement units (IMUs) for estimating segmental kinetic energy. As a step towards this goal, this study reports a benchmark experiment that demonstrates the accuracy of IMU-derived estimates of segmental kinetic energy. The study is conducted on a well-characterized mechanical system, a double pendulum that also serves as an apt model for the lower or upper extremities. A two-node IMU array is used to measure the kinematics of each segment as input to the segmental kinetic energy computations. The segments are also instrumented with two high-precision optical encoders that provide the truth data for kinetic energy. The segmental kinetic energies estimated using the IMU array remain within 3.5% and 3.9% of the kinetic energies measured by the optical encoders for the top and bottom segments, respectively, for the freely decaying pendulum oscillations considered. These promising results support the future development of body-worn IMU arrays for real-time estimates of segmental kinetic energy for health, sports and military applications.

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Hagemann, Thomas, Hardwig Blumenthal, Christian Kraft, and Hubert Schwarze. "A Study on Energetic and Hydraulic Interaction of Combined Journal and Thrust Bearings." In ASME Turbo Expo 2015: Turbine Technical Conference and Exposition. American Society of Mechanical Engineers, 2015. http://dx.doi.org/10.1115/gt2015-43460.

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A theoretical algorithm for the analysis of bidirectional interaction of combined journal and thrust bearings is presented. While many theoretical and experimental investigations on the operating behavior of single journal and thrust bearings can be found only few results for combined bearings are available. However, combined bearings interact by exchanging lubricant and heat which can affect significant changes of boundary conditions compared to a single bearing application. Therefore, a novel procedure is developed to combine two separate codes for journal and thrust bearings in order to iteratively determine the coupling boundary conditions due to the special design of the entire bearing unit. The degree of interaction strongly depends on the type of lubrication. In a first step predictions are verified by measurement data for a combined bearing with a fixed-pad offset-halves journal bearing and a directed lubricated tilting-pad thrust bearing. Experiments were conducted on a high speed test rig up to sliding speeds of 107 m/s at the mean radius of the thrust bearing. As expected the interaction of the two oil films is comparably low in the investigated speed and load range for this bearing design because of the active lubrication of both bearings and the low hydraulic resistance of the thrust bearing. In order to theoretically investigate interaction of thrust and journal bearings in more details a combined bearing with fixed-pad thrust parts lubricated exclusively by the side flow of the journal bearing is studied. A variation of modeling level, pocket design of the journal part, thrust load and rotating frequency provides the following results: (i) hydraulic and energetic interaction have to be modelled in details, (ii) the axial flow resistance of the pockets strongly influences flow rates and the pressure level at the interfaces (iii) the level of interface pressure rises with increasing thrust loads and decreasing rotor speed, (iv) the axial bearing clearance is rather of minor importance for the investigated bearing. Finally, improvements in order to predict operating conditions more precisely are comprehensively discussed.

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Rodriguez, Adrian, and Alan Bowling. "Study of the Stick-Slip Transition of Newton’s Cradle With Friction." In ASME 2013 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference. American Society of Mechanical Engineers, 2013. http://dx.doi.org/10.1115/detc2013-12420.

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This work uses a new discrete approach to analyze the stick-slip transition of Newton’s cradle with frictional contact. The consideration of friction here leads to a simultaneous, multiple point, indeterminate collision. This work strictly adheres to the assumptions of rigid body modeling in conjunction with the notion that the configuration of the system are constant in the short time span of the collision, which enforces a kinematic relationship between the impact points. The post-impact velocities are determined by using the work-energy relationship of a collision and an energetic coefficient of restitution (ECOR) to model energy dissipation. A three and six degree-of-freedom (DOF) model of the system is considered in this work to examine the stick-slip transition and simulate the post-impact behavior. Simulations are conducted for each model using different coefficients of friction (COFs). The results obtained are compared to theoretical and experimental results reported in other works.

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MANNING, THELMA G., HENRY GRAU, MICHAEL FAIR, NATHAN PEABODY, EUGENE ROZUMOV, and VIRAL PANCHAL. "LOW TEMPERATURE SENSITIVITY ROCKET PROPELLANT." In 32ND INTERNATIONAL SYMPOSIUM ON BALLISTICS. Destech Publications, Inc., 2022. http://dx.doi.org/10.12783/ballistics22/36091.

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The purpose of this effort is to develop propellants with reduced oxygen balance and low molecular weight. This is to achieve increased performance results as well as low temperature and pressure sensitivity characteristics. Theoretical estimates of heat formation for these molecules were made and propellant performances were calculated. In these materials, as the oxygen balance was decreased, a lower temperature sensitivity could be achieved as well as a higher specific impulse and an increase in the drop height. The propellant should have a high but steady burn rate that exhibits low-pressure and temperature sensitivity. The main objective of this study is to characterize and evaluate a new energetic plasticizer. This will be comprised of a eutectic mixture of linear dinitrodiazaalkanes energetic materials, named as DNDA-57. This will consist of numerous chemical and thermal characterization, including safe handling and small scale sensitivity testing. This paper will discuss the DNDA-57 material evaluation at a preliminary level.

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Coverdale, C. A., C. B. Darrow, B. A. Hammel, W. B. Mori, C. Decker, K. C. Tzeng, C. Joshi, and C. Clayton. "Observation of Forward Raman Scattering and Energetic Electrons in High Intensity, Sub-Picosecond Laser, Underdense Plasma Interaction Experiments." In High Resolution Fourier Transform Spectroscopy. Washington, D.C.: Optica Publishing Group, 1994. http://dx.doi.org/10.1364/hrfts.1994.pd4.

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Many theoretical and computer simulation results have been published recently involving the interaction of short pulse, high intensity lasers with underdense plasmas.1-4 This is a new regime in which to study laser-plasma interactions since the length of the laser pulse is shorter than the Rayleigh range of the laser and the length of the plasma (cτL< LR, Lp). Developments in laser technology over the last several years have made the experimental investigation of this regime possible. In this paper, we describe the first experimental observation of forward stimulated Raman scattering and energetic electrons from the interaction of a subpicosecond, high intensity laser with an underdense plasma.

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Yilanci, Ahmet, Ibrahim Dincer, and Harun Kemal Ozturk. "Determination of Some Thermodynamic Parameters for a Hybrid Solar-Hydrogen System." In ASME 2008 2nd International Conference on Energy Sustainability collocated with the Heat Transfer, Fluids Engineering, and 3rd Energy Nanotechnology Conferences. ASMEDC, 2008. http://dx.doi.org/10.1115/es2008-54342.

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In this paper, we undertake a study to investigate the performance of a hybrid photovoltaic-hydrogen system through energy and exergy efficiencies, improvement potential. This will help identify the irreversibilities (exergy destructions) for performance improvement purposes. Energetic and exergetic renewability ratios are also introduced for grid dependent hybrid energy systems. A case study is presented to highlight the importance of the thermodynamic parameters and show them using some actual and theoretical data. Three different energy demand options from photovoltaic panels to the consumer are identified and considered for the analysis. The minimum and maximum overall energy and exergy efficiencies of the system are calculated based on these options. It is found that the overall energy efficiency values of the system vary between 0.88% and 9.7% while minimum and maximum overall exergy efficiency values of the system are 0.77% and 9.3%, respectively. The monthly improvement potential of the system is also studied to investigate the seasonal performance.

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Schobeiri, M. T., K. Read, and J. Lewalle. "Effect of Unsteady Wake Passing Frequency on Boundary Layer Transition, Experimental Investigation and Wavelet Analysis." In ASME 1995 International Gas Turbine and Aeroengine Congress and Exposition. American Society of Mechanical Engineers, 1995. http://dx.doi.org/10.1115/95-gt-437.

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Detailed experimental and theoretical investigations were carried out to study the effect of unsteady wake passing frequency on the boundary layer transition along the concave surface of a curved plate under a zero longitudinal pressure gradient Periodic unsteady flow with different passing frequencies is generated utilizing an unsteady flow research facility with a rotating cascade of rods positioned upstream of the curved plate. Extensive unsteady boundary layer measurements are carried out. The data are analyzed using conventional and wavelet-based methods. Local time scales are defined as those of the most energetic fluctuations, and are calculated from wavelet transforms of the velocity signals. The dominant time scales are mapped as functions of the distance to the plate, the downstream location, and the phase relative to the wake-passing. Furthermore, conditional sampling is applied, laminar turbulent time scales are calculated and the effects of wake passing frequency on these scales are shown.

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Lorente, Sylvie. "Design of a Latent Thermal Energy Storage System From Constructal Approach." In ASME 2017 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2017. http://dx.doi.org/10.1115/imece2017-70594.

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This work presents a theoretical and numerical analysis of thermal energy storage obtained from Phase Change Materials. We start with a study of the early stages of natural convection in the liquid, followed by an analysis of the entire duration of the melting process. Both are based on scale analysis. The numerical simulations cover the entire process, and validate all the features predicted by theory. Next we apply the methodology to the design of an efficient storage system made of a tank filled with a Phase Change Material like paraffin wax. A hot fluid circulates through pipes located within the tank; it is heated by means of a solar panel. The total volume of tubes is fixed. We apply Constructal design to determine the optimal allocation of the hot tubes so that each transfer mode is used at the best moment. We demonstrate that the overall energetic performance can be improved by endowing the system with freedom to morph.

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Gater, Brittany, and Javid Bayandor. "Power Regeneration of a Bioinspired Electromechanical Propulsive Fin." In ASME 2017 Fluids Engineering Division Summer Meeting. American Society of Mechanical Engineers, 2017. http://dx.doi.org/10.1115/fedsm2017-69559.

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Bioinspired swimming methods have become highly attractive due to the potential for low environmental impact and high efficiency. However, although the efficiency has been quantified for select robotic and theoretical models, this paper explores more directly how requisite power consumption of an undulatory fin is affected by desired swimming speed. It further introduces and quantifies a method for recovering energy from the flow. First, CFD was used to simulate a cross-section of a fish fin with a wave number of 1.2 and a linearly increasing amplitude envelope. Flow speed and fin wave frequency were varied to determine interactive effects on force production and power requirements. The data from these simulations was fitted with polynomial functions over the range used for the study. To determine the potential for power regeneration from the flow, the fin was augmented with a mathematical model of a DC motor and shaft driving it. By incorporating the motor model into the fin analysis, the authors analyzed the amount of power input, or power regeneration, into the system from a constant velocity fluid flow, and developed a relationship between flow velocity and power regeneration. This relationship provides insight into both the level of power regeneration for the fin if held fixed in constant flow, and the minimum flow speed to regenerate energy at a desired rate. The determination of the relationships between efficiency and mode of operation will provide insight into the energetic efficiency of robotic designs using this method. Furthermore, the possibility of power recovery could pave the way for longer lasting underwater robots in extended missions. The determination of both efficiency and power regeneration capability will provide insight into the energetic feasibility of using, and improving on, the current capabilities of bioinspired underwater propulsion.

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Samanta, S., and S. Ghosh. "Energetic and Environmental Analysis of Partial Repowering of a Coal Fired Power Plant Through Upstream GT Integration and Employing Waste Heated Feed Water Heaters." In ASME Turbo Expo 2014: Turbine Technical Conference and Exposition. American Society of Mechanical Engineers, 2014. http://dx.doi.org/10.1115/gt2014-27027.

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This paper presents a theoretical study of partial repowering scheme for an existing 210MW coal fired power plant and reports predicted performance improvement obtainable from the repowering by using Cycle Tempo software. In this method old boiler is used as it is, only modifying its air heater and forced flow sections. Out of four operating coal mills, one mill is considered to be taken out. A new natural gas fired gas turbine (GT) block is considered to be integrated with the existing plant whose exhaust is fed to the existing boiler. The GT size is selected such that its exhaust provide heat input equivalent to the replaced coal mill. The burners associated with that coal mill are assumed to be modified to handle hot exhaust gas from the GT block. It is noticed that a substantial amount of energy is available in the flue gas, coming out from the boiler, after the air preheater which can partially meet the heat loads of feed water heaters. This helps in saving of intermediate pressure (IP) and low pressure (LP) bleed steam and consequent increase in the output of the steam cycle. The partial repowering results in nearly 40% increase in capacity of the plant (from 210MW to 284MW). It also results in substantial increase in overall efficiency of the repowered plant by 28%, and consequent decrease in plant heat rate by 22%. The specific CO2 emission of the plant decreases about 31% after repowering.

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Reports on the topic "Energetics - Theoretical Study"

Xu, Chunhui. Theoretical study of the structure, energetics, and dynamics of silicon and carbon systems using tight-binding approaches. Office of Scientific and Technical Information (OSTI), October 1991. http://dx.doi.org/10.2172/5073116.

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