transition probabilities
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Atoms ◽  
2022 ◽  
Vol 10 (1) ◽  
pp. 7
Author(s):  
Stephan Fritzsche

Open f-shell elements still constitute a great challenge for atomic theory owing to their (very) rich fine-structure and strong correlations among the valence-shell electrons. For these medium and heavy elements, many atomic properties are sensitive to the correlated motion of electrons and, hence, require large-scale computations in order to deal consistently with all relativistic, correlation and rearrangement contributions to the electron density. Often, different concepts and notations need to be combined for just classifying the low-lying level structure of these elements. With Jac, the Jena Atomic Calculator, we here provide a toolbox that helps to explore and deal with such elements with open d- and f-shell structures. Based on Dirac’s equation, Jac is suitable for almost all atoms and ions across the periodic table. As an example, we demonstrate how reasonably accurate computations can be performed for the low-lying level structure, transition probabilities and lifetimes for Th2+ ions with a 5f6d ground configuration. Other, and more complex, shell structures are supported as well, though often for a trade-off between the size and accuracy of the computations. Owing to its simple use, however, Jac supports both quick estimates and detailed case studies on open d- or f-shell elements.


2022 ◽  
Vol 12 (1) ◽  
Author(s):  
Thomas Banks ◽  
Bingnan Zhang

We complete an old argument that causal diamonds in the crunching region of the Lorentzian continuation of a Coleman-Deluccia instanton for transitions out of de Sitter space have finite area, and provide quantum models consistent with the principle of detailed balance, which can mimic the instanton transition probabilities for the cases where this diamond is larger or smaller than the causal patch of de Sitter space. We review arguments that potentials which do not have a positive energy theorem when the lowest de Sitter minimum is shifted to zero, may not correspond to real models of quantum gravity.


Author(s):  
Daniel Tobias Michaeli ◽  
Julia Caroline Michaeli ◽  
Tobias Boch ◽  
Thomas Michaeli

Abstract Purpose Novel pharmaceutical treatments reducing cardiovascular events in dyslipidaemia patients must demonstrate clinical efficacy and cost-effectiveness to promote long-term adoption by patients, physicians, and insurers. Objective To assess the cost-effectiveness of statin monotherapy compared to additive lipid-lowering therapies for primary and secondary cardiovascular prevention from the perspective of Germany’s healthcare system. Methods Transition probabilities and hazard ratios were derived from cardiovascular outcome trials for statin combinations with icosapent ethyl (REDUCE-IT), evolocumab (FOURIER), alirocumab (ODYSSEY), ezetimibe (IMPROVE-IT), and fibrate (ACCORD). Costs and utilities were retrieved from previous literature. The incidence of major adverse cardiovascular events was simulated with a Markov cohort model. The main outcomes were the incremental cost-effectiveness ratios (ICER) per quality adjusted life year (QALY) gained. Results For primary prevention, the addition of icosapent ethyl to statin generated 0.81 QALY and €14,732 costs (ICER: 18,133), whereas fibrates yielded 0.63 QALY and € − 10,516 costs (ICER: − 16,632). For secondary prevention, the addition of ezetimibe to statin provided 0.61 QALY at savings of € − 5,796 (ICER: − 9,555) and icosapent ethyl yielded 0.99 QALY and €14,333 costs (ICER: 14,485). PCSK9 inhibitors offered 0.55 and 0.87 QALY at costs of €62,722 and €87,002 for evolocumab (ICER: 114,639) and alirocumab (ICER: 100,532), respectively. A 95% probability of cost-effectiveness was surpassed at €20,000 for icosapent ethyl (primary and secondary prevention), €119,000 for alirocumab, and €149,000 for evolocumab. Conclusions For primary cardiovascular prevention, a combination therapy of icosapent ethyl plus statin is a cost-effective use of resources compared to statin monotherapy. For secondary prevention, icosapent ethyl, ezetimibe, evolocumab, and alirocumab increase patient benefit at different economic costs.


2022 ◽  
Author(s):  
Nicolaj Kofod ◽  
Patrick Nawrocki ◽  
Thomas Just Sørensen

Lanthanide luminescence has been treated separate from molecular photophysics, although the underlying phenomena are the same. As the optical transitions observed in the trivalent lanthanide ions are forbidden, they do belong to the group that molecular photophysics have yet to conquer, yet the experimental descriptors remains valid. Determining these have proven challenging as full control/knowledge of sample composition is a prerequisite. This has been achieved, and here the luminescence quantum yields (ϕlum), luminescence lifetimes (τobs), oscillator strengths (f ), and the rates of non-radiative (knr) and radiative (kr ≡ A) deactivation of [Eu(H2O)9]3+ was determined for the trigonal tricapped prismatic (TTP) coordination geometry. Further, it was shown that instead of a full photophysical characterization, it is possible to relate changes in transition probabilities to the relative parameter Arel, which does not require reference data. While Arel does not afford comparisons between experiments, it resolves emission intensity changes due to emitter properties—changes in A—from intensity changes due to environmental effects—changes in knr, and differences in the number of photons absorbed. When working with fluorescence this may seem trivial, when working with lanthanide luminescence it is not.


2022 ◽  
Author(s):  
A. Kharchenko

Abstract. The article presents the results of research in the direction of improving technological equipment for internal threading of parts in a flexible automated production. Methods for assessing the operational and technological reliability of a flexible manufacturing module (FMM) of thread processing are considered, which can be used as the basis for the developed method of synthesis of its elements. It is proposed to consider the technological system of the flexible manufacturing module (FMM) of thread processing as a system in which transitions from state to state occur under the action of the simplest flows with parameters of the transition probabilities of a continuous Markov chain. The developed mathematical model describing the state of the FMM taking into account the failures of the functioning of its elements, parametric failures, as well as taking into account the recovery after these types of failures, makes it possible to reflect the influence on the operation of the module of the parameters of the flows of failures and restorations of the tool, machine tool, fixture, loading device. The solution of the obtained systems of equations of final probabilities allows for given (or experimentally obtained) intensities of failure streams (functioning and parametric) for FMM threading to obtain the values of the probability of failure-free operation, as well as the probabilities of finding the system in an inoperative state due to corresponding failures. The measures taken make it possible to solve the synthesis problem at the level of structural and layout optimization, so that at the stage of parametric synthesis to determine the elements that are vulnerable according to the developed criterion, the improvement of which will lead to the creation of the most efficient system.


Nutrients ◽  
2022 ◽  
Vol 14 (1) ◽  
pp. 215
Author(s):  
Kirthi Menon ◽  
Barbora de Courten ◽  
Dianna J. Magliano ◽  
Zanfina Ademi ◽  
Danny Liew ◽  
...  

In this paper, we assess the cost-effectiveness of 1 g daily of carnosine (an over the counter supplement) in addition to standard care for the management of type 2 diabetes and compare it to standard care alone. Dynamic multistate life table models were constructed in order to estimate both clinical outcomes and costs of Australians aged 18 years and above with and without type 2 diabetes over a ten-year period, 2020 to 2029. The dynamic nature of the model allowed for population change over time (migration and deaths) and accounted for the development of new cases of diabetes. The three health states were ‘Alive without type 2 diabetes’, ‘Alive with type 2 diabetes’ and ‘Dead’. Transition probabilities, costs, and utilities were obtained from published sources. The main outcome of interest was the incremental cost-effectiveness ratio (ICER) in terms of cost per year of life saved (YoLS) and cost per quality-adjusted life year (QALY) gained. Over the ten-year period, the addition of carnosine to standard care treatment resulted in ICERs (discounted) of AUD 34,836 per YoLS and AUD 43,270 per QALY gained. Assuming the commonly accepted willingness to pay threshold of AUD 50,000 per QALY gained, supplemental dietary carnosine may be a cost-effective treatment option for people with type 2 diabetes in Australia.


Author(s):  
В.С. Михайлов ◽  
П.Ю. Бабенко ◽  
А.П. Шергин ◽  
А.Н. Зиновьев

The Auger transition probabilities are calculated while filling a vacancy on 2pπ orbital in a Ne+-Ne quasimolecule, a short-lived system which is formed when ion and atom approach each other and decays when they scatter. For the first time calculations were performed for various degrees of particles ionization in quasimolecule. It was found that with increase of collision energy and decrease of distance of the closest approach of particles the system ionization degree increases very significantly (from 2 to 6). Using of the quantum mechanical approach and taking into account the dynamics of collisions made it possible for the first time to describe quantitatively the experimental spectra of Auge electrons for a complex many-electron quasimolecule. From the whole variety of possible Auger decay channels the dominant contribution of the transition was established, from the initial 3dπ-3dπ state to the 2pπ orbital.


Entropy ◽  
2021 ◽  
Vol 24 (1) ◽  
pp. 65
Author(s):  
Jesús E. Garca ◽  
Verónica A. González-López ◽  
Gustavo H. Tasca ◽  
Karina Y. Yaginuma

In the framework of coding theory, under the assumption of a Markov process (Xt) on a finite alphabet A, the compressed representation of the data will be composed of a description of the model used to code the data and the encoded data. Given the model, the Huffman’s algorithm is optimal for the number of bits needed to encode the data. On the other hand, modeling (Xt) through a Partition Markov Model (PMM) promotes a reduction in the number of transition probabilities needed to define the model. This paper shows how the use of Huffman code with a PMM reduces the number of bits needed in this process. We prove the estimation of a PMM allows for estimating the entropy of (Xt), providing an estimator of the minimum expected codeword length per symbol. We show the efficiency of the new methodology on a simulation study and, through a real problem of compression of DNA sequences of SARS-CoV-2, obtaining in the real data at least a reduction of 10.4%.


2021 ◽  
Vol 2/2021 (35) ◽  
pp. 76-92
Author(s):  
Arkadiusz Manikowski ◽  

This paper presents a way of using the Markov chain model for the analysis of migration based on the example of banknote migration between regions in Poland. We have presented the application of the methodology for estimating one-step transition probabilities for the Markov chain based on macro-data gathered during the project conducted in the National Bank of Poland (NBP) in the period of December 2015–2018. We have shown the usefulness of state-aggregated Markov chain not only as a model of banknote migration but as migration in general. The banknotes are considered here as goods, so their migration is strictly related to, inter alia, the movement of people (commuting to work, business trips, etc.).Thus, the gravity-like properties of cash migration pointed to the gravity model as one of the most pervasive empirical models in regional science. Transition probability of the Markov chain expressing the attractive force between regions allows for estimating the gravity model for the identification of relevant reasons of note and, consequently, people migration.


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