The effective role of Dirac mass in nonlinear optical spectra of silicene

2019 ◽  
Vol 36 (5) ◽  
pp. 1222 ◽  
Author(s):  
Upendra Kumar
Keyword(s):  
Nonlinear Optical ◽  
Optical Spectra ◽  
Dirac Mass ◽  
Effective Role

scholarly journals Nonlinear Spectroscopy in the Condensed Phase: The Role of Duschinsky Rotations and Third Order Cumulant Contributions

2020 ◽  
Author(s):  
Tim Zuehlsdorff ◽  
Hanbo Hong ◽  
Liang Shi ◽  
Christine Isborn
Keyword(s):  
Excited State ◽  
Condensed Phase ◽  
Nonlinear Optical ◽  
Order Term ◽  
Optical Spectra ◽  
Cumulant Expansion ◽  
Third Order ◽  
The Third ◽  
Mode Mixing

First-principles modeling of nonlinear optical spectra in the condensed phase is highly challenging because both environment and vibronic interactions can play a large role in determining spectral shapes and excited state dynamics. Here, we compute two dimensional electronic spectroscopy (2DES) signals based on a cumulant expansion of the energy gap fluctuation operator, with a specific focus on analyzing mode mixing effects introduced by the Duschinsky rotation and the role of the third order term in the cumulant expansion for both model and realistic condensed phase systems. We show that for a harmonic model system, the third order cumulant correction captures effects introduced by a mismatch in curvatures of ground and excited state potential energy surfaces, as well as effects of mode mixing. We also demonstrate that 2DES signals can be accurately reconstructed from purely classical correlation functions using quantum correction factors. We then compute nonlinear optical spectra for the Nile red and Methylene blue chromophores in solution, assessing the third order cumulant contribution for realistic systems. We show that the third order cumulant correction is strongly dependent on the treatment of the solvent environment, revealing the interplay between environmental polarization and the electronic-vibrational coupling.

scholarly journals Nonlinear Spectroscopy in the Condensed Phase: The Role of Duschinsky Rotations and Third Order Cumulant Contributions

2020 ◽  
Author(s):  
Tim Zuehlsdorff ◽  
Hanbo Hong ◽  
Liang Shi ◽  
Christine Isborn
Keyword(s):  
Excited State ◽  
Condensed Phase ◽  
Nonlinear Optical ◽  
Order Term ◽  
Optical Spectra ◽  
Cumulant Expansion ◽  
Third Order ◽  
The Third ◽  
Mode Mixing

First-principles modeling of nonlinear optical spectra in the condensed phase is highly challenging because both environment and vibronic interactions can play a large role in determining spectral shapes and excited state dynamics. Here, we compute two dimensional electronic spectroscopy (2DES) signals based on a cumulant expansion of the energy gap fluctuation operator, with a specific focus on analyzing mode mixing effects introduced by the Duschinsky rotation and the role of the third order term in the cumulant expansion for both model and realistic condensed phase systems. We show that for a harmonic model system, the third order cumulant correction captures effects introduced by a mismatch in curvatures of ground and excited state potential energy surfaces, as well as effects of mode mixing. We also demonstrate that 2DES signals can be accurately reconstructed from purely classical correlation functions using quantum correction factors. We then compute nonlinear optical spectra for the Nile red and Methylene blue chromophores in solution, assessing the third order cumulant contribution for realistic systems. We show that the third order cumulant correction is strongly dependent on the treatment of the solvent environment, revealing the interplay between environmental polarization and the electronic-vibrational coupling.

Reforming the Role of the African Commission on Human and Peoples’ Rights in Advancing Democratic Principles and Human Rights in African Countries: An Examination Using the Lens of Swaziland/ eSwatini

2019 ◽  
Vol 34 (2) ◽  
Author(s):  
Jeremy Sarkin
Keyword(s):  
Human Rights ◽  
African Countries ◽  
Individual Country ◽  
The Status ◽  
Effective Role ◽  
Limited Compliance ◽  
Fact Finding ◽  
Democratic Principles ◽  
African Commission

This article explores the role of the African Commission on Human and Peoples’ Rights and the role it plays regarding human rights in individual country situations in Africa. It specifically examines the extent to which it has been able to advance a human rights agenda in countries with long-standing human rights problems. The article uses Swaziland/ eSwatini as a lens to examine the matter, because of the longstanding problems that exist in that country. This is done to indicate how the institution works over time on a country’s human rights problems. The article examines a range of institutional structural matters to establish how these issues affect the role of the Commission in its work. The article examines the way in which the Commission uses its various tools, including its communications, the state reporting processes, fact-finding visits, and resolutions, to determine whether those tools are being used effectively. The article examines how the Commission’s processes issues also affect it work. Issues examined negatively affecting the Commission are examined, including problems with the status of its resolutions and communications, limited compliance with its outcomes, and inadequate state cooperation. Reforms necessary to enhance to role and functions of the Commission are surveyed to determine how the institution could become more effective. The African Union’s (AU|) Kagame Report on AU reform is briefly reviewed to examine the limited view and focus of AU reform processes and why AU reform ought to focus on enhancing human rights compliance. The article makes various suggestions on necessary institutional reforms but also as far as the African Commission’s procedures and methods of work to allow it to have a far more effective role in the promotion and protection of human rights on the continent. It is noted that political will by the AU and African states is the largest obstacle to giving the Commission the necessary independence, support and assistance that it needs to play the role in Africa that it should.

Few-Particle Effects in Nonlinear Optical Spectra of Semiconductor Quantum Dots

1999 ◽  
Vol 571 ◽  
Author(s):  
Ulrich Hohenesteri ◽  
Fausto Rossi ◽  
Elisa Molinari
Keyword(s):  
Quantum Dots ◽  
Density Matrix ◽  
Nonlinear Optical ◽  
Coherent Control ◽  
Optical Spectra ◽  
Carrier Dynamics ◽  
Semiconductor Quantum Dots ◽  
Nonequilibrium Carrier ◽  
Optical Nonlinearities ◽  
Matrix Approach

ABSTRACTWe present a density-matrix approach for the description of nonequilibrium carrier dynamics in optically excited semiconductor quantum dots, that explicitly accounts for exciton-exciton as well as exciton-carrier interactions. Within this framework, we analyze few-particle effects in the optical spectra and provide a consistent description of additional peaks appearing at high photoexcitation density. We discuss possible applications of such optical nonlinearities in future coherent-control experiments.

scholarly journals Intraoperative neurophysiological mapping and monitoring in spinal tumor surgery: sirens or indispensable tools?

2016 ◽  
Vol 41 (2) ◽  
pp. E18 ◽  
Author(s):  
Antonino Scibilia ◽  
Carmen Terranova ◽  
Vincenzo Rizzo ◽  
Giovanni Raffa ◽  
Adolfo Morelli ◽  
...  
Keyword(s):  
Complex Function ◽  
Spinal Tumor ◽  
Neurological Deficits ◽  
Neurological Injury ◽  
Neurophysiological Monitoring ◽  
Predictive Values ◽  
Effective Role ◽  
Mapping Techniques ◽  
Sensitivity Specificity

Spinal tumor (ST) surgery carries the risk of new neurological deficits in the postoperative period. Intraoperative neurophysiological monitoring and mapping (IONM) represents an effective method of identifying and monitoring in real time the functional integrity of both the spinal cord (SC) and the nerve roots (NRs). Despite consensus favoring the use of IONM in ST surgery, in this era of evidence-based medicine, there is still a need to demonstrate the effective role of IONM in ST surgery in achieving an oncological cure, optimizing patient safety, and considering medicolegal aspects. Thus, neurosurgeons are asked to establish which techniques are considered indispensable. In the present study, the authors focused on the rationale for and the accuracy (sensitivity, specificity, and positive and negative predictive values) of IONM in ST surgery in light of more recent evidence in the literature, with specific emphasis on the role of IONM in reducing the incidence of postoperative neurological deficits. This review confirms the role of IONM as a useful tool in the workup for ST surgery. Individual monitoring and mapping techniques are clearly not sufficient to account for the complex function of the SC and NRs. Conversely, multimodal IONM is highly sensitive and specific for anticipating neurological injury during ST surgery and represents an important tool for preserving neuronal structures and achieving an optimal postoperative functional outcome.

Studying structure of Coronaviridae, analyzing their geometry and focusing on the role of electronic applications in health awareness of viruses

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Eman Almuhur ◽  
Manal Al-Labadi ◽  
Amani Shatarah ◽  
Nazneen Khan ◽  
Raeesa Bashir
Keyword(s):  
Human Body ◽  
Design Methodology ◽  
Health Technology ◽  
Content Type ◽  
Mathematical Structures ◽  
Infected People ◽  
Movement Mechanism ◽  
Effective Role ◽  
Health Applications

Purpose This study aims to focus on electronic applications that have an effective role in raising the awareness of the dangers of viruses’ transmission from person-to-person and their positive and important impact on people’s lives. Design/methodology/approach The authors illustrated the effects of socializing with infected people on a human body by a model in geometry and how the prospected antibiotic annihilates the structure of the virus. The authors discussed vital operations inside the human body to expound the geometry of objects that are closed under their operations, such as viruses, especially Coronaviridae. Findings Also, the authors discussed some of the e-health applications in Jordan. As e-health activities, programs and applications have been given attention, the authors focused on potentials for constructing strategies that lead to create a featuring health technology. Originality/value Moreover, in this study, the authors explored the structure and geometry of Coronaviridae family, especially coronavirus that causes lots of diseases, and explained its movement mechanism using the mathematical structures.

scholarly journals Effective role of CaO/P 2 O 5 ratio on SiO 2 -CaO-P 2 O 5 glass system

2017 ◽  
Vol 8 (3) ◽  
pp. 279-288 ◽  
Author(s):  
P. Kiran ◽  
V. Ramakrishna ◽  
M. Trebbin ◽  
N.K. Udayashankar ◽  
H.D. Shashikala
Keyword(s):  
Glass System ◽  
Effective Role
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