On the constraints that duality imposes on the broken SU(6)w structure of the baryonic resonance photocouplings

1979 ◽  
Vol 57 (6) ◽  
pp. 815-823
Author(s):  
C. Avilez ◽  
G. Cocho
Keyword(s):  
High Energy ◽  
Low Energy ◽  
Meson Photoproduction ◽  
Baryonic Resonance ◽  
Energy Constraints ◽  
Natural Parity ◽  
Parity Exchange ◽  
Good Agreement

The absence of exotics and the natural parity exchange dominance in the t-channel, in high energy meson photoproduction of nucleons impose, via duality, restrictions on the baryonic resonance photocouplings. In a broken SU(6)w parametrization these constraints allow different couplings for the [Formula: see text] and [Formula: see text] baryonic resonances and impose relations between the transitions to the 70 and 56SU(6)W representations. It is shown that the low energy baryonic resonance photocouplings are in good agreement with these high energy constraints.

Theoretical photoionization study of Ti9+ ion

2020 ◽  
Author(s):  
Hongbin Wang ◽  
Gang Jiang
Keyword(s):  
Cross Sections ◽  
Energy Levels ◽  
Radiative Transition ◽  
High Energy ◽  
Low Energy ◽  
Transition Rates ◽  
Channel Coupling ◽  
R Matrix ◽  
Good Consistency ◽  
Good Agreement

Photoionization (PI) of Ti<sup>9+</sup> ion is investigated by the Dirac R-matrix method. Multi-Configuration Dirac-Fock (MCDF) calculations are performed to construct accurate target functions. Good agreement of energy levels and radiative transition rates indicate the accuracy of target functions. PI cross sections show good consistency between length and velocity forms. The results are consistent with the previous theoretical values in high-energy regions. Partial waves contribution to the total PI cross sections are discussed for the ground and metastable states. Moreover, the PI cross sections are dominated by many resonance structures and affected by the channel coupling effects in low-energy region. In addition to providing data for the Opacity Project TOPbase, the present work promotes plasma simulation and diagnosis.

scholarly journals High-energy constraints from low-energy neutrino nonstandard interactions

2020 ◽  
Vol 101 (9) ◽  
Author(s):  
Jorge Terol-Calvo ◽  
Mariam Tórtola ◽  
Avelino Vicente
Keyword(s):  
High Energy ◽  
Low Energy ◽  
Energy Neutrino ◽  
Energy Constraints

Hopping Barriers at Step Edges

1993 ◽  
Vol 312 ◽  
Author(s):  
Pavel Šmilauer ◽  
Mark R. Wilby ◽  
Dimitri D. Vvedensky
Keyword(s):  
High Energy ◽  
Layer Growth ◽  
Low Energy ◽  
Step Edge ◽  
Solid Model ◽  
Layer By Layer ◽  
Ion Sputtering ◽  
High Energy Electron ◽  
Diffraction Intensity ◽  
Good Agreement

AbstractThe recent discovery of reentrant layer-by-layer growth in metal homoepitaxy has stimulated considerable interest in the role played by barriers to hopping down descending steps. However, the existence of step-edge barriers for semiconductors is far from being clearly established. We have investigated the effects of step-edge barriers for epitaxial growth and the “inverse” process of low-energy ion sputtering on metal surfaces using Monte Carlo simulations of a solid-on-solid model. Our results are in good agreement with available experimental data and provide new insights into the microscopic origins of the evolution of surface morphology during these processes. Our simulations also suggest that such step-edge barriers can explain the observed temperature and time dependence of the reflection high-energy electron diffraction intensity during post-growth recovery on GaAs(001), which sheds new light on this controversial subject.

Low energy vs. high energy depositional settings and related sedimentary bodies in early Senenian rudist bearing carbonate shelves (central-southern Italy)

2001 ◽  
Vol 28 (1) ◽  
pp. 37-40 ◽  
Author(s):  
Gabriele Carannante ◽  
A. Laviano ◽  
D. Ruberti ◽  
Lucia Simone ◽  
G. Sirna ◽  
...  
Keyword(s):  
Southern Italy ◽  
High Energy ◽  
Low Energy ◽  
Depositional Settings

Computational Study on the Kinetics and Mechanisms of Unimolecular Reactions of (Z)-(Z)-N-(λ5-phosphanylidene) Formohydrazonic Formic Anhydride: Intramolecular aza-Wittig Reaction in Competition with Mumm Rearrangement

2020 ◽  
Vol 17 (11) ◽  
pp. 884-889
Author(s):  
Somayeh Mirdoraghi ◽  
Hamed Douroudgari ◽  
Farideh Piri ◽  
Morteza Vahedpour
Keyword(s):  
Rate Constants ◽  
Density Functional ◽  
Wittig Reaction ◽  
Computational Study ◽  
Single Step ◽  
Low Energy ◽  
Coupled Cluster ◽  
Unimolecular Reaction ◽  
Single Step Reaction ◽  
Good Agreement

For (Z)-(Z)-N-(λ5-phosphanylidene) formohydrazonic formic anhydride, Aza-Wittig reaction and Mumm rearrangement are studied using both density functional and coupled cluster theories. For this purpose, two different products starting from one substrate are considered that are competing with each other. The obtained products, P1 and P2, are thermodynamically favorable. The product of the aza-Wittig reaction, P1, is more stable than the product of Mumm rearrangement (P2). For the mentioned products, just one reliable pathway is separately proposed based on unimolecular reaction. Therefore, the rate constants based on RRKM theory in 300-600 K temperature range are calculated. Results show that the P1 generation pathway is a suitable path due to low energy barriers than the path P2. The first path has three steps with three transition states, TS1, TS2, and TS3. The P2 production path is a single-step reaction. In CCSD level, the computed barrier energies are 14.55, 2.196, and 10.67 kcal/mol for Aza-Wittig reaction and 42.41 kcal/mol for Mumm rearrangement in comparison with the corresponding complexes or reactants. For final products, the results of the computational study are in a good agreement with experimental predictions.

Transportation: Fuel Energies

2017 ◽  
Author(s):  
Peter Rez
Keyword(s):  
Energy Density ◽  
Fossil Fuels ◽  
High Energy ◽  
Ease Of Use ◽  
Low Energy ◽  
High Energy Density ◽  
Nuclear Fuels ◽  
Liquid Hydrocarbons ◽  
Transportation Fuel ◽  
Journey Time

Transportation efficiency can be measured in terms of the energy needed to move a person or a tonne of freight over a given distance. For passengers, journey time is important, so an equally useful measure is the product of the energy used and the time taken for the journey. Transportation requires storage of energy. Rechargeable systems such as batteries have very low energy densities as compared to fossil fuels. The highest energy densities come from nuclear fuels, although, because of shielding requirements, these are not practical for most forms of transportation. Liquid hydrocarbons represent a nice compromise between high energy density and ease of use.

scholarly journals Low-Energy Electron Damage to Condensed-Phase DNA and Its Constituents

2021 ◽  
Vol 22 (15) ◽  
pp. 7879
Author(s):  
Yingxia Gao ◽  
Yi Zheng ◽  
Léon Sanche
Keyword(s):  
Condensed Phase ◽  
Genetic Material ◽  
High Energy ◽  
Dna Lesions ◽  
Low Energy ◽  
Experimental Investigations ◽  
Experimental Conditions ◽  
Strand Breaks ◽  
Sequence Of Events ◽  
Wide Range

The complex physical and chemical reactions between the large number of low-energy (0–30 eV) electrons (LEEs) released by high energy radiation interacting with genetic material can lead to the formation of various DNA lesions such as crosslinks, single strand breaks, base modifications, and cleavage, as well as double strand breaks and other cluster damages. When crosslinks and cluster damages cannot be repaired by the cell, they can cause genetic loss of information, mutations, apoptosis, and promote genomic instability. Through the efforts of many research groups in the past two decades, the study of the interaction between LEEs and DNA under different experimental conditions has unveiled some of the main mechanisms responsible for these damages. In the present review, we focus on experimental investigations in the condensed phase that range from fundamental DNA constituents to oligonucleotides, synthetic duplex DNA, and bacterial (i.e., plasmid) DNA. These targets were irradiated either with LEEs from a monoenergetic-electron or photoelectron source, as sub-monolayer, monolayer, or multilayer films and within clusters or water solutions. Each type of experiment is briefly described, and the observed DNA damages are reported, along with the proposed mechanisms. Defining the role of LEEs within the sequence of events leading to radiobiological lesions contributes to our understanding of the action of radiation on living organisms, over a wide range of initial radiation energies. Applications of the interaction of LEEs with DNA to radiotherapy are briefly summarized.

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