Role of stray light in the formation of high-resolution resonant photoelectron spectra: an experimental and theoretical study of N2

2004 ◽  
Vol 134 (1) ◽  
pp. 49-65 ◽  
Author(s):  
R. Feifel ◽  
A. Baev ◽  
F. Gel’mukhanov ◽  
H. Ågren ◽  
M. Andersson ◽  
...  

High resolution photoelectron spectra, obtained with He I (58.4 nm), He II (30.4 nm) and Ne I (73.6 nm) resonance radiation, are reported for SO 2 F2 and ClO 3 F. Vertical ionization potentials (i.p.), and in many cases estimates of adiabatic i.p. also, are tabulated for both of the compounds. Ab initio s.c.f.m.o. calculations of the electronic structures are also presented. The calculations indicate considerable participation by 3d orbitals of the central atom in both molecules, and some support for this may be drawn from the excellent agreement of eigenvalues with the measured i.p. In both molecules detailed vibrational fine structure is observed, and this may be correlated well with the calculated bonding character.


2004 ◽  
Vol 43 (06) ◽  
pp. 185-189 ◽  
Author(s):  
J. T. Kuikka

Summary Aim: Serotonin transporter (SERT) imaging can be used to study the role of regional abnormalities of neurotransmitter release in various mental disorders and to study the mechanism of action of therapeutic drugs or drugs’ abuse. We examine the quantitative accuracy and reproducibility that can be achieved with high-resolution SPECT of serotonergic neurotransmission. Method: Binding potential (BP) of 123I labeled tracer specific for midbrain SERT was assessed in 20 healthy persons. The effects of scatter, attenuation, partial volume, mis-registration and statistical noise were estimated using phantom and human studies. Results: Without any correction, BP was underestimated by 73%. The partial volume error was the major component in this underestimation whereas the most critical error for the reproducibility was misplacement of region of interest (ROI). Conclusion: The proper ROI registration, the use of the multiple head gamma camera with transmission based scatter correction introduce more relevant results. However, due to the small dimensions of the midbrain SERT structures and poor spatial resolution of SPECT, the improvement without the partial volume correction is not great enough to restore the estimate of BP to that of the true one.


Author(s):  
LM Sconfienza ◽  
F Lacelli ◽  
G Grillo ◽  
G Serafini ◽  
G Garlaschi ◽  
...  

1998 ◽  
Vol 38 (6) ◽  
pp. 1027
Author(s):  
Kyoung Suk Kim ◽  
Young Tong Kim ◽  
Eun Joo Kwon ◽  
Choung Sik Choi ◽  
Han Heag Im ◽  
...  

2020 ◽  
pp. 6-13
Author(s):  
V. K. Potemkin

The article presents the results of a theoretical study of the influence processes of the developed digital technologies and the activities of enterprises and organizations on the changing role of man in labor and their social improvement. The necessity of a balanced and consistent approach to create conditions for the use of digital technologies in practical activities and determining the con- sequences not only in enterprises and organizations, but also in the conscious behavior and social realities of all workers, without exception, is substantiated. The main directions of the development of digital technologies are determined, involving the wide participation of workers in their use in enterprises and organizations.


Materials ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 3913
Author(s):  
Aljawhara H. Almuqrin ◽  
Mohamed Hanfi ◽  
K. G. Mahmoud ◽  
M. I. Sayyed ◽  
Hanan Al-Ghamdi ◽  
...  

The radiation shielding competence was examined for a binary glass system xLa2O3 + (1 − x) TeO2 where x = 5, 7, 10, 15, and 20 mol% using MCNP-5 code. The linear attenuation coefficients (LACs) of the glasses were evaluated, and it was found that LT20 glass has the greatest LAC, while LT5 had the least LAC. The transmission factor (TF) of the glasses was evaluated against thicknesses at various selected energies and was observed to greatly decrease with increasing thickness; for example, at 1.332 MeV, the TF of the LT5 glass decreased from 0.76 to 0.25 as the thickness increased from 1 to 5 cm. The equivalent atomic number (Zeq) of the glasses gradually increased with increasing photon energy above 0.1 MeV, with the maximum values observed at around 1 MeV. The buildup factors were determined to evaluate the accumulation of photon flux, and it was found that the maximum values for both can be seen at around 0.8 MeV. This research concluded that LT20 has the greatest potential in radiation shielding applications out of the investigated glasses due to the glass having the most desirable parameters.


2021 ◽  
Vol 22 (6) ◽  
pp. 3220
Author(s):  
Álvaro Fernández-Ochoa ◽  
Francisco Javier Leyva-Jiménez ◽  
María De la Luz Cádiz-Gurrea ◽  
Sandra Pimentel-Moral ◽  
Antonio Segura-Carretero

The approaches based on high-resolution analytical techniques, such as nuclear magnetic resonance or mass spectrometry coupled to chromatographic techniques, have a determining role in several of the stages necessary for the development of functional foods. The analyses of botanical extracts rich in bioactive compounds is one of the fundamental steps in order to identify and quantify their phytochemical composition. However, the compounds characterized in the extracts are not always responsible for the bioactive properties because they generally undergo metabolic reactions before reaching the therapeutic targets. For this reason, analytical techniques are also applied to analyze biological samples to know the bioavailability, pharmacokinetics and/or metabolism of the compounds ingested by animal or human models in nutritional intervention studies. In addition, these studies have also been applied to determine changes of endogenous metabolites caused by prolonged intake of compounds with bioactive potential. This review aims to describe the main types and modes of application of high-resolution analytical techniques in all these steps for functional food development.


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