scholarly journals RELATIVISTIC THEORY OF SPECTRAL CHARACTERISTICS OF PIONIC ATOMIC SYSTEMS: APPLICATION TO HEAVY SYSTEMS

2021 ◽  
pp. 78-85
Author(s):  
Yu. Dubrovskaya ◽  
O. Khetselius ◽  
I. Serga ◽  
Yu. Chernyakova
Keyword(s):  
Excited States ◽  
Spectral Characteristics ◽  
Finite Size ◽  
Nuclear Interaction ◽  
Charged Sphere ◽  
Spectral Parameters ◽  
Atomic Systems ◽  
Kaonic Atoms ◽  
Klein Gordon ◽  
Nuclear Effects

A new theoretical approach to energy and spectral parameters of the hadronic (pionic and kaonic) atoms in the excited states with precise accounting for the relativistic, radiation and nuclear effects is presented. There are presented data of calculation of the energy and spectral parameters for pionic atoms of the 93Nb, 173Yb, 181Ta , 197Au, with accounting for the radiation (vacuum polarization), nuclear (finite size of a nucleus ) and the strong pion-nuclear interaction corrections. The measured values of the Berkley, CERN and Virginia laboratories and alternative data based on other versions of the Klein-Gordon-Fock theories with taking into account for a finite size of the nucleus in the model uniformly charged sphere and the standard Uhling-Serber potential approach for account for the radiation corrections are listed too.

Effects of Long-Term Tracheostomy on Spectral Characteristics of Vowel Production

1991 ◽  
Vol 34 (5) ◽  
pp. 1057-1065 ◽  
Author(s):  
Ruth Saletsky Kamen ◽  
Ben C. Watson
Keyword(s):  
Vocal Tract ◽  
Spectral Characteristics ◽  
Group Differences ◽  
Vowel Production ◽  
Formant Frequency ◽  
Motor Patterns ◽  
Spectral Parameters ◽  
Oral Motor ◽  
Vowel Space

This study investigated the effects of long-term tracheostomy on the development of speech. Eight children who underwent tracheotomy during the prelingual period were compared to matched controls on selected spectral parameters of the speech acoustic signal and standard measures of oral-motor, phonologic, and articulatory proficiency. Analysis of formant frequency values revealed significant between-group differences. Children with histories of long-term tracheostomy showed reduced acoustic vowel space, as defined by group formant frequency values. This suggests that these children were limited in their ability to produce extreme vocal tract configurations for vowels /a,i,u/ postdecannulation. Oral motor patterns were less mature, and sound substitutions were not only more variable for this group, but also reflected a persistent overlay of maladaptive compensations developed during cannulation.

scholarly journals Irreversible work versus fidelity susceptibility for infinitesimal quenches

2017 ◽  
Vol 31 (06) ◽  
pp. 1750065 ◽  
Author(s):  
Simone Paganelli ◽  
Tony J. G. Apollaro
Keyword(s):  
Quantum System ◽  
Excited States ◽  
Ground State ◽  
Finite Size ◽  
Scaling Relations ◽  
Zero Temperature ◽  
Finite Size Scaling ◽  
Ising Chain ◽  
Extra Term ◽  
Explicit Relation

We compare the irreversible work produced in an infinitesimal sudden quench of a quantum system at zero temperature with its ground state fidelity susceptibility, giving an explicit relation between the two quantities. We find that the former is proportional to the latter but for an extra term appearing in the irreversible work which includes also contributions from the excited states. We calculate explicitly the two quantities in the case of the quantum Ising chain, showing that at criticality they exhibit different scaling behaviors. The irreversible work, rescaled by square of the quench’s amplitude, exhibits a divergence slower than that of the fidelity susceptibility. As a consequence, the two quantities obey also different finite-size scaling relations.

scholarly journals Sturmian expansions for two-electron atomic systems: Singly and doubly excited states

2010 ◽  
Vol 82 (4) ◽  
Author(s):  
A. L. Frapiccini ◽  
J. M. Randazzo ◽  
G. Gasaneo ◽  
F. D. Colavecchia
Keyword(s):  
Excited States ◽  
Atomic Systems ◽  
Doubly Excited States ◽  
Doubly Excited

scholarly journals A novel ultrasound technique to detect early chronic kidney disease

F1000Research ◽  
2019 ◽  
Vol 7 ◽  
pp. 448
Author(s):  
Dulitha K. Hewadikaram ◽  
Mudhitha Bandara ◽  
Amal N. Pattivedana ◽  
Hiran H. E. Jayaweera ◽  
Kithsiri M. Jayananda ◽  
...  
Keyword(s):  
Chronic Kidney Disease ◽  
Kidney Disease ◽  
Spectral Characteristics ◽  
Unknown Etiology ◽  
Ultrasound Wave ◽  
Spectral Parameters ◽  
Ultrasound Technique ◽  
Kidney Fibrosis ◽  
Urine Albumin ◽  
Dry Zone

Chronic kidney disease (CKD) of unknown etiology is recognized as a major public health challenge and a leading cause of morbidity and mortality in the dry zone in Sri Lanka. CKD is asymptomatic and are diagnosed only in late stages. Evidence points to strong correlation between progression of CKD and kidney fibrosis. Several biochemical markers of renal fibrosis have been associated with progression of CKD. However, no marker is able to predict CKD consistently and accurately before being detected with traditional clinical tests (serum creatinine, and cystatin C, urine albumin or protein, and ultrasound scanning). In this paper, we hypothesize that fibrosis in the kidney, and therefore the severity of the disease, is reflected in the frequency spectrum of the scattered ultrasound from the kidney. We present a design of a simple ultrasound system, and a set of clinical and laboratory studies to identify spectral characteristics of the scattered ultrasound wave from the kidney that correlates with CKD. We believe that spectral parameters identified in these studies can be used to detect and stratify CKD at an earlier stage than what is possible with current markers of CKD.

scholarly journals SPECTRAL CHARACTERISTICS OF TUNDRA AND FOREST TUNDRA LANDSCAPES DURING THE YEARS OF SUMMER TEMPERATURE ANOMALIES

2020 ◽  
Vol 4 ◽  
pp. 88-103
Author(s):  
T.B. Titkova ◽  
◽  
A.N. Zolotokrylin ◽  
V.V. Vinogradov ◽  
◽  
...  
Keyword(s):  
Surface Temperature ◽  
Regulatory Mechanism ◽  
Spectral Characteristics ◽  
Extreme Temperature ◽  
Regulatory Mechanisms ◽  
Spectral Parameters ◽  
Vegetation Diversity ◽  
Forest Tundra ◽  
Temperature Anomalies ◽  
Novaya Zemlya

The warming at high latitudes, remaining in recent years, has a direct impact on arctic and subarctic landscapes. Possible changes of this landscapes under the climate warming are closely related with regulatory mechanisms for the underlying surface temperature. The circumstances of forming radiation and evapotranspirational regulatory mechanisms for the surface temperature were explored for tundra (from arctic to southern) and forest tundra landscapes of Novaya Zemlya and Western Siberia. The MODIS data of surface spectral characteristics were used, and more specifically albedo (Al) and surface temperature (Ts) for July 2000-2019. The work shows that the radiation regulatory mechanism of the surface temperature is dominated in glacial and polar desert landscapes of Arctic and Subarctic with a predominance of stony and rubble types of surfaces with lichens. At the same time, radiative surface temperature control mechanism in mountain and arctic tundra of Novaya Zemlya almost does not depend on weather anomalies and so far has a little implication for the temperature trend. In the mainland and forest tundra, the evapotranspirational regulatory mechanism for the surface temperature starts to prevail. This is supported by the increasing of monthly average air temperatures to 15-16°С, which is beneficial to the vegetation diversity. In subzones of the southern and forest tundra, the connection of albedo and surface temperature depends on altitudes, slope exposure and especially on extreme temperature anomalies. In basins, or hydromorphic complexes, in cold years against the backdrop of wetlands the regulatory mechanism for the surface temperature prevails, and in warm years the humidity decreasing leads to the highest vegetation development and the connection type can turn into the evapotranspirational one. On the high grounds the return process is observed, which is also connected with the changes in humidification conditions. In forest tundra, where the air temperature rises and the canopy height increases, the evapotranspirational mechanism of spectral parameters Al–Ts connections is weakening. As a result, in southern and forest tundra two balanced steady states of the connection types of surface spectral characteristics can exist in relation to lighting conditions and temperature anomalies.

Theoretical Investigation on the Characteristics of Leak Noise for Natural Gas Pipelines

2020 ◽  
Vol 28 (03) ◽  
pp. 2050005
Author(s):  
Zewei Zhang ◽  
Hongyong Yuan ◽  
Ming Fu ◽  
Tao Chen ◽  
Yan Gao ◽  
...  
Keyword(s):  
Fluid Dynamics ◽  
Natural Gas ◽  
Dynamic Pressure ◽  
Spectral Characteristics ◽  
Orifice Diameter ◽  
Dipole Source ◽  
Gas Pipelines ◽  
Buried Pipelines ◽  
Spectral Parameters ◽  
Natural Gas Pipelines

This paper is concerned with the spectral characteristics of leak noise at the source relevant to fluid dynamics for natural gas pipelines. Comparison is made between the flow field characteristics for the buried and above-ground pipelines to demonstrate the differences in aero-acoustics generation mechanism. The fundamental spectral parameters including the sound pressure level (SPL) and power spectral density (PSD), are extracted to characterize the leak noise under different pipeline conditions of operation pressure and leak orifice diameter. Numerical results show that the leak noise of buried pipelines has less energy and are more concentrated at lower frequencies, compared with that of above-ground pipelines. It is demonstrated that leak noise is predominantly governed by the dipole and the quadrupole sources, generated from the gas–solid interaction and turbulent disturbance, respectively. It is shown that the dipole source is attenuated and the quadrupole source is amplified with the leak orifice diameter for buried pipelines whereas both are amplified for above-ground pipelines. Moreover, it is suggested that the feature parameters of fluid dynamics, such as the average dynamic pressure and turbulent kinetic energy, can be used to characterize the leak noise mechanism for natural gas pipelines.

Excited states of three-electron atomic systems with two vacancies in the K shell

1978 ◽  
Vol 29 (4) ◽  
pp. 1243-1247
Author(s):  
U. I. Safronova ◽  
V. S. Senashenko
Keyword(s):  
Excited States ◽  
Atomic Systems

QUALITY OF HYPERSPHERICAL ADIABATIC APPROXIMATION FOR EXCITED STATES OF ATOMIC SYSTEMS

2004 ◽  
Vol 19 (29) ◽  
pp. 4973-4984 ◽  
Author(s):  
TAPAN KUMAR DAS ◽  
BARNALI CHAKRABARTI
Keyword(s):  
Excited States ◽  
Adiabatic Approximation ◽  
Invariance Condition ◽  
Constant Matrix ◽  
Shape Invariance ◽  
Atomic Systems ◽  
Potential Matrix ◽  
Hyperspherical Adiabatic ◽  
Common Function

We calculate ground and several low-lying excited states of various two electron atoms using hyperspherical adiabatic approximation (HAA). Its spectracular accuracy, as compared to exact numerical results of a set of coupled differential equations, demands a better understanding of its mechanism. It is seen that factorizability of the potential matrix into a product of a common function of the global length (hyperradius) and a constant matrix, is responsible for this remarkable success. This is a result of the shape invariance condition in multidimensional supersymmetric quantum mechanics.

Sign in / Sign up

Export Citation Format

Share Document