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Author(s):  
Nkpa M. Ogarekpe ◽  
Jonah Chukwuemeka Agunwamba ◽  
Maurice G. Ekpenyong

The study investigated the structure of the integrated solar and hydraulic jump enhanced waste stabilization pond (ISHJEWSP) variables. Also, to determine the cluster of the most important variables that account for the performance of the ISHJEWSP using principal component analysis (PCA). Three sets of experimental ponds were constructed with varying locations of point of initiation of hydraulic jump. Wastewater samples collected from the inlet and outlet for varying inlet velocities were examined for physicochemical and bacteriological characteristics for a period of nine months. The Pearson’s R-matrix and KMO statistic were used in evaluating the structure of the variables. Consequently, the variables of temperature, pH, algae concentration, solar radiation, and locations of the point of initiation of hydraulic jump were subjected to PCA. Two components had eigenvalues above the Jolliffe’s criterion and in combination explained 90.66% of the total variance. The inflexion of the scree plot justified the retained components. The analysis after rotation revealed that the parameters of pH, temperature, solar radiation, and algal concentration loaded highly to component 1. This underscores the precedence of ambient climatic conditions, alongside the state of the wastewater in general, to the inlet velocity and location of point of initiation of hydraulic jump.


Author(s):  
Abdul Kabir ◽  
Jameel-Un Nabi

Abstract Radiative capture p+9Be → 10B+γ at energies bearing astrophysical importance is a key process for the spectroscopic study of 10B. In this work, we consider the radiative capture cross-section for the 9Be(p, γ)10B within the framework of the potential model and the R-matrix method for the multi-entrance channel cases. In certain cases, when the potential fails, therefore, the R-matrix approach is better to use for the description of partial components of the cross-section that have sharp or broad resonances. For all possible electric and magnetic dipole transitions, partial components of the astrophysical S-factor are computed. The computed value of the total S-factor at zero energy is consistent with the reported results.


2021 ◽  
pp. 102-109
Author(s):  
V. Buyadzhi

An advanced relativistic energy approach combined with a relativistic many-body perturbation theory with ab initio zeroth approximation  is used to calculate the electron-collision excitation cross-sections for complex multielectron systems.  The relativistic many-body perturbation theory is used alongside the gauge-invariant scheme to generate an optimal Dirac-Kohn-Sham- Debye-Hückel one-electron representation.  The results of relativistic calculation (taking into account the exchange and correlation corrections) of the electron collision cross-sections of excitation for the neon-like ion of the krypton  are presented and compared with alternative results calculation on the basis of the R-matrix method in the Breit-Pauli approximation, in the relativistic distorted wave approximation and R- matrix method in combination with Dirac-Fock approximation


2021 ◽  
Author(s):  
Jie Ren ◽  
xichao ruan ◽  
Wei Jiang ◽  
Jie Bao ◽  
jincheng wang ◽  
...  

Abstract The capture cross sections of the 169Tm(n, γ) reaction were measured at the back streaming white neutron beam line (Back-n) of the China Spallation Neutron Source (CSNS) using four C6D6 liquid scintillation detectors. To obtain accurate cross sections, the background subtraction, normalization, and correction were carefully taken into consideration in the data analysis. For the resonance at 3.9 eV, the R-matrix code SAMMY was used to determine the resonance parameters with internally normalization method. While the average capture cross sections of 169Tm in the energy range between 30 keV and 300 keV were extracted relative to the 197Au(n, γ) reaction. The measured cross sections of the 169Tm(n, γ) reaction were reported in logarithmically equidistant energy bins with 20 bins per energy decade with a total uncertainty of 5.4%-7.0% in this paper, and described in terms of average resonance parameters by means of a Hauser-Feshbach calculation with fluctuations. Both of the point-wise cross sections and the averge resonance parameters showed fair agreement with the evaluated values of ENDF/B-VIII.0 library in the energy region studied.


Author(s):  
David Stevens ◽  
Tamara Babij ◽  
J R Machacek ◽  
James P Sullivan

Abstract This paper presents measurements of low energy electron scattering from pyridine. The low energy positron beamline at the Australian National University was used for these measurements, with a change in operational parameters allowing for the measurement of electron scattering processes. We have collected data for the low energy total cross section for electron scattering, as well as measurements of the differential cross sections (DCS) for electrons up to 3 eV impact energy. The operation of the beamline will be briefly outlined and data are compared to R-matrix and Schwinger multichannel theoretical calculations, as well as previous experimental data.


2021 ◽  
Vol 2021 (12) ◽  
Author(s):  
David M. Schmidtt

Abstract We derive, within the Hamiltonian formalism, the classical exchange algebra of a lambda deformed string sigma model in a symmetric space directly from a 4d holomorphic Chern-Simons theory. The explicit forms of the extended Lax connection and R-matrix entering the Maillet bracket of the lambda model are explained from a symmetry principle. This approach, based on a gauge theory, may provide a mechanism for taming the non-ultralocality that afflicts most of the integrable string theories propagating in coset spaces.


2021 ◽  
Vol 392 ◽  
pp. 108000
Author(s):  
Gabriel Frieden
Keyword(s):  
Type A ◽  

2021 ◽  
Vol 2021 (12) ◽  
Author(s):  
Sergey Derkachov ◽  
Gwenaël Ferrando ◽  
Enrico Olivucci

Abstract We present a basis of eigenvectors for the graph building operators acting along the mirror channel of planar fishnet Feynman integrals in d-dimensions. The eigenvectors of a fishnet lattice of length N depend on a set of N quantum numbers (uk, lk ), each associated with the rapidity and bound-state index of a lattice excitation. Each excitation is a particle in (1 + 1)-dimensions with O(d) internal symmetry, and the wave-functions are formally constructed with a set of creation/annihilation operators that satisfy the corresponding Zamolodchikovs-Faddeev algebra. These properties are proved via the representation, new to our knowledge, of the matrix elements of the fused R-matrix with O(d) symmetry as integral operators on the functions of two spacetime points. The spectral decomposition of a fishnet integral we achieved can be applied to the computation of Basso-Dixon integrals in higher dimensions.


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