Réactions 3He + 9Be, d + 10B → 3α et excitation du 12C dans la région 29–34 MeV

1977 ◽  
Vol 55 (23) ◽  
pp. 2113-2120 ◽  
Author(s):  
G. Goulard ◽  
R. Roy ◽  
R. J. Slobodrian
Keyword(s):  
Excited States ◽  
Energy Region ◽  
Energy Spectra ◽  
Two Stage ◽  
Final State ◽  
New Information ◽  
Stage Process ◽  
Α Particles

Excited states of 12C between 29 and 34 MeV are studied through the 3He + 9Be and d + 10B reactions leading to three α particles in the final state. Correlated energy spectra are analyzed with a two-stage process and new information is given about the studied excited energy region.

scholarly journals Benchmark PhotoIonization Cross-Sections of Neutral Scandium from the Ground and Excited States

Atoms ◽  
2021 ◽  
Vol 9 (4) ◽  
pp. 83
Author(s):  
Swaraj S. Tayal ◽  
Oleg Zatsarinny
Keyword(s):  
Excited States ◽  
Cross Sections ◽  
Energy Region ◽  
Bound States ◽  
Electron Ionization ◽  
Final State ◽  
Close Coupling ◽  
Resonance Structures ◽  
The Cross ◽  
Ionic States

The B-spline R-matrix method has been used to investigate cross-sections for photoionization of neutral scandium from the ground and excited states in the energy region from the 3d and 4s valence electron ionization thresholds to 25 eV. The initial bound states of Sc and the final residual Sc+ ionic states have been accurately calculated by combining the multiconfiguration Hartree-Fock method with the frozen-core close-coupling approach. The lowest 20 bound states of Sc I belonging to the ground 3d4s2 and excited 3d24s, 3d24p, 3d4s4p, 4s24p, and 3d3 configurations have been considered as initial states. The 81 LS final ionic states of Sc+ belonging to the terms of 3p63d2, 3p63d4l (l = 0–3), 3p63d5l (l = 0–3), 3p63d6s, 3p64s2, 3p64s4l (l = 0–3), 3p64s5l (l = 0–1), and 3p64p2 configurations have been included in the final-state close-coupling expansion. The cross-sections are dominated by complicated resonance structures in the low energy region converging to several Sc+ ionic thresholds. The inclusion of all these final ionic states has been noted to significantly impact the near-threshold resonance structures and background cross-sections. The important scattering channels for leaving the residual ion in various final states have been identified, and the 3d electron ionization channels have been noted to dominate the cross-sections at higher photon energies.

scholarly journals Two-Stage Biodiesel Synthesis from Used Cooking Oil with a High Acid Value via an Ultrasound-Assisted Method

Energies ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3703
Author(s):  
Ming-Chien Hsiao ◽  
Wei-Ting Lin ◽  
Wei-Cheng Chiu ◽  
Shuhn-Shyurng Hou
Keyword(s):  
Acid Value ◽  
Molar Ratio ◽  
Optimal Conditions ◽  
Two Stage ◽  
Cooking Oil ◽  
High Acid ◽  
Used Cooking Oil ◽  
Biodiesel Synthesis ◽  
Stage Process ◽  
Ultrasound Assisted

In this study, ultrasound was used to accelerate two-stage (esterification–transesterification) catalytic synthesis of biodiesel from used cooking oil, which originally had a high acid value (4.35 mg KOH/g). In the first stage, acid-catalyzed esterification reaction conditions were developed with a 9:1 methanol/oil molar ratio, sulfuric acid dosage at 2 wt %, and a reaction temperature of 60 °C. Under ultrasound irradiation for 40 min, the acid value was effectively decreased from 4.35 to 1.67 mg KOH/g, which was decreased to a sufficient level (<2 mg KOH/g) to avoid the saponification problem for the subsequent transesterification reaction. In the following stage, base-catalyzed transesterification reactions were carried out with a 12:1 methanol/oil molar ratio, a sodium hydroxide dosage of 1 wt %, and a reaction temperature of 65 °C. Under ultrasound-assisted transesterification for 40 min, the conversion rate of biodiesel reached 97.05%, which met the requirement of EN 14214 standard, i.e., 96.5% minimum. In order to evaluate and explore the improvement of the ultrasound-assisted two-stage (esterification–transesterification) process in shortening the reaction time, additional two-stage biodiesel synthesis experiments using the traditional mechanical stirring method under the optimal conditions were further carried out in this study. It was found that, under the same optimal conditions, using the ultrasound-assisted two-stage process, the total reaction time was significantly reduced to only 80 min, which was much shorter than the total time required by the conventional method of 140 min. It is worth noting that compared with the traditional method without ultrasound, the intensification of the ultrasound-assisted two-stage process significantly shortened the total time from 140 min to 80 min, which is a reduction of 42.9%. It was concluded that the ultrasound-assisted two-stage (esterification–transesterification) catalytic process is an effective and time-saving method for synthesizing biodiesel from used cooking oil with a high acid value.

scholarly journals Food behavior change in late-life widowhood: A two-stage process

Appetite ◽  
2015 ◽  
Vol 95 ◽  
pp. 399-407 ◽  
Author(s):  
Elisabeth Vesnaver ◽  
Heather H. Keller ◽  
Olga Sutherland ◽  
Scott B. Maitland ◽  
J.L. Locher
Keyword(s):  
Behavior Change ◽  
Late Life ◽  
Food Behavior ◽  
Two Stage ◽  
Stage Process

High-efficiency CuInSe2 solar cells prepared by the two-stage process

Solar Cells ◽  
1989 ◽  
Vol 27 (1-4) ◽  
pp. 299-306 ◽  
Author(s):  
Bulent M. Basol ◽  
Vijay K. Kapur ◽  
Richard C. Kullberg
Keyword(s):  
Solar Cells ◽  
High Efficiency ◽  
Two Stage ◽  
Stage Process
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