scholarly journals Measurement of Nuclear Lifetimes and B(E2) Values in 130Xe as a Test for E(5) Symmetry

2020 ◽  
Vol 19 ◽  
pp. 33
Author(s):  
T. Konstantinopoulos ◽  
Et Al.

As a continuation of the previous measurement in 128Xe [1], [2], [3], another E(5) candidate, 130Xe, has been studied through the novel experimental technique Coulex-plunger in inverse kinematics. The measurements have been undertaken at the JYFL accelerator facility in Jyvaskyl ̈a, Finland. For the purpose of this experiment the Cologne plunger was coupled to the JYFL cyclotron which delivered the 130Xe beam. Excited states in 130Xe were populated by the natFe(130Xe, 130Xe*) reaction at E(130Xe)=500 MeV and the subsequent de-excitations were detected in the JUROGAM γ-ray array. By applying the well known Differential Decay Curve Method (DDCM) [4], lifetimes of the 2^+_1 and 4^+_1 excited states were determined. In addition, since the investigated nucleus is excited through the Coulomb interaction, it is possible to perform a full Coulomb excitation analysis of the data using the computer code GOSIA [5] which will allow the determination of B(E2) values of the transitions up to the 6^+_1 excited state.

2019 ◽  
Vol 18 ◽  
pp. 7
Author(s):  
T. Konstantinopoulos ◽  
... Et al.

Lifetime measurements in 128Xe have been undertaken at the JYFL accelerator facility using the novel Coulex-plunger in inverse kinematics technique [1], [2]. Excited states in 128Xe were populated by the natFe(128Xe, 128Xe*) reaction at E(128Xe)=525 MeV and the subsequent de-excitations were detected in the JUROGAM γ-ray array. Two independent analyses of the data were performed. Firstly the Differential Decay Curve Method (DDCM) [3] was applied to determine lifetimes of the excited states. Secondly, matrix elements and their corresponding B(E2) values, were extracted using the computer code GOSIA [4]. The results are presented and compared with the adopted values. Also, B(E2) values obtained from this work are compared to the values predicted by the E(5) critical-point symmetry, since 128Xe has been proposed as a candidate for E(5) symmetry [5].


2018 ◽  
Vol 194 ◽  
pp. 03003 ◽  
Author(s):  
Ralph Kern ◽  
Robert Stegmann ◽  
Norbert Pietralla ◽  
Georgi Rainovski ◽  
Liam Paul Gaffney ◽  
...  

Projectile Coulomb excitation experiments were performed at HIE-ISOLDE at CERN with the radioactive ion beams of 140Nd and 142Sm. Ions with an energy of 4:62 MeV/A were impinging on a 1.45 mg/cm2 thick 208Pb target. The γ-rays depopulating the Coulomb-excited states were recorded by the HPGe-array MINIBALL and scattered particles were detected by a double-sided silicon strip detector. Experimental intensities were used for the determination of electromagnetic transition matrix elements. A preliminary result of the B(M1; 2+3 → 2+1) of 140Nd and an upper limit for the case of 142Sm are revealing the main fragments of the proton-neutron mixed-symmetry 2+1;ms states.


2018 ◽  
Vol 194 ◽  
pp. 03004
Author(s):  
Mariya Trichkova ◽  
Marcel Beckers ◽  
Kalin Gladnishki ◽  
Alfred Dewald ◽  
Andrey Blazhev ◽  
...  

Lifetimes of excited states of 124Ba were measured by the Recoil Distance Doppler Shift (RDDS) technique. The γ-ray coincidence data were analysed by the Differential Decay Curve method (DDCM). The trend of the experimentally deduced normalized B(E2) values reveals a drop at the 8+1 state, which may be caused by structural changes in the backbending region.


2019 ◽  
Vol 18 ◽  
pp. 169
Author(s):  
S. F. Ashley ◽  
... Et al.

Lifetimes of the excited states in the yrast band of 102Pd have been deter- mined using the Recoil-Distance Doppler Shift experiment at INFN, Labo- ratori Nazionali di Legnaro. Excited states in 102Pd were populated by the 92Zr(13C,3n)102Pd fusion-evaporation reaction. Lifetimes were deduced using the Differential Decay Curve method and the corresponding B(E2) values were compared to the E(5) critical-point symmetry, and also the U(5) and O(6) limits of the Interacting Boson Model-1. It is evident that 102Pd agrees poorly with the predicted E(5) symmetry but has a very good (and somewhat surprising) agreement with the O(6) limit.


TAPPI Journal ◽  
2012 ◽  
Vol 11 (10) ◽  
pp. 9-17
Author(s):  
ALESSANDRA GERLI ◽  
LEENDERT C. EIGENBROOD

A novel method was developed for the determination of linting propensity of paper based on printing with an IGT printability tester and image analysis of the printed strips. On average, the total fraction of the surface removed as lint during printing is 0.01%-0.1%. This value is lower than those reported in most laboratory printing tests, and more representative of commercial offset printing applications. Newsprint paper produced on a roll/blade former machine was evaluated for linting propensity using the novel method and also printed on a commercial coldset offset press. Laboratory and commercial printing results matched well, showing that linting was higher for the bottom side of paper than for the top side, and that linting could be reduced on both sides by application of a dry-strength additive. In a second case study, varying wet-end conditions were used on a hybrid former machine to produce four paper reels, with the goal of matching the low linting propensity of the paper produced on a machine with gap former configuration. We found that the retention program, by improving fiber fines retention, substantially reduced the linting propensity of the paper produced on the hybrid former machine. The papers were also printed on a commercial coldset offset press. An excellent correlation was found between the total lint area removed from the bottom side of the paper samples during laboratory printing and lint collected on halftone areas of the first upper printing unit after 45000 copies. Finally, the method was applied to determine the linting propensity of highly filled supercalendered paper produced on a hybrid former machine. In this case, the linting propensity of the bottom side of paper correlated with its ash content.


1982 ◽  
Vol 47 (7) ◽  
pp. 1973-1978 ◽  
Author(s):  
Jiří Karhan ◽  
Zbyněk Ksandr ◽  
Jiřina Vlková ◽  
Věra Špatná

The determination of alcohols by 19F NMR spectroscopy making use of their reaction with hexafluoroacetone giving rise to hemiacetals was studied on butanols. The calibration curve method and the internal standard method were used and the results were mutually compared. The effects of some experimental conditions, viz. the sample preparation procedure, concentration, spectrometer setting, and electronic integration, were investigated; the conditions, particularly the concentrations, proved to have a statistically significant effect on the results of determination. For the internal standard method, the standard deviation was 0.061 in the concentration region 0.032-0.74 mol l-1. The method was applied to a determination of alcohols in the distillation residue from an oxo synthesis.


Author(s):  
Nesma M Fahmy ◽  
Adel M Michael

Abstract Background Modern built-in spectrophotometer software supporting mathematical processes provided a solution for increasing selectivity for multicomponent mixtures. Objective Simultaneous spectrophotometric determination of the three naturally occurring antioxidants—rutin(RUT), hesperidin(HES), and ascorbic acid(ASC)—in bulk forms and combined pharmaceutical formulation. Method This was achieved by factorized zero order method (FZM), factorized derivative method (FD1M), and factorized derivative ratio method (FDRM), coupled with spectrum subtraction(SS). Results Mathematical filtration techniques allowed each component to be obtained separately in either its zero, first, or derivative ratio form, allowing the resolution of spectra typical to the pure components present in Vitamin C Forte® tablets. The proposed methods were applied over a concentration range of 2–50, 2–30, and 10–100 µg/mL for RUT, HES, and ASC, respectively. Conclusions Recent methods for the analysis of binary mixtures, FZM and FD1M, were successfully applied for the analysis of ternary mixtures and compared to the novel FDRM. All were revealed to be specific and sensitive with successful application on pharmaceutical formulations. Validation parameters were evaluated in accordance with the International Conference on Harmonization guidelines. Statistical results were satisfactory, revealing no significant difference regarding accuracy and precision. Highlights Factorized methods enabled the resolution of spectra identical to those of pure drugs present in mixtures. Overlapped spectra of ternary mixtures could be resolved by spectrum subtraction coupled FDRM (SS-FDRM) or by successive application of FZM and FD1M.


Microbiome ◽  
2021 ◽  
Vol 9 (1) ◽  
Author(s):  
Alberto Pascual-García

AbstractIn this comment, we analyse the conceptual framework proposed by Aguirre de Cárcer (Microbiome 7:142, 2019), introducing the novel concept of Phylogenetic Core Groups (PCGs). This notion aims to complement the traditional classification in operational taxonomic units (OTUs), widely used in microbial ecology, to provide a more intrinsic taxonomical classification which avoids the use of pre-determined thresholds. However, to introduce this concept, the author frames his proposal in a wider theoretical framework based on a conceptualization of selection that we argue is a tautology. This blurs the subsequent formulation of an assembly principle for microbial communities, favouring that some contradictory examples introduced to support the framework appear aligned in their conclusions. And more importantly, under this framework and its derived methodology, it is not possible to infer PCGs from data in a consistent way. We reanalyse the proposal to identify its logical and methodological flaws and, through the analysis of synthetic scenarios, we propose a number of methodological refinements to contribute towards the determination of PCGs in a consistent way. We hope our analysis will promote the exploration of PCGs as a potentially valuable tool, helping to bridge the gap between environmental conditions and community composition in microbial ecology.


1993 ◽  
Vol 48 (1) ◽  
pp. 58-67 ◽  
Author(s):  
Joseph Grobe ◽  
Duc Le Van ◽  
Gudrun Lange

The course of the reactions o f fluorophosphaalkenes F3CP = C (F)OR [R = Me (1), Et (2)] with methanol or ethanol strongly depends on the experimental conditions. Thus at 70 °C a mixture of the 2-phosphapropionic acid ester F3CP (H )CO2R [R = Me (3), Et (4)] and trifluoromethylphosphane H2PCF3 is formed [molar ratio: 3 or 4 /H2 CF3 ≈1/1]. If the precursors F3CP (H )CO2R [R = Me (3), Et) are used as starting materials, the reaction with ROH under the same conditions affords 3 and 4, respectively, (90 to 95% yield) with only traces of H2PCF 3. In the presence o f iPr2NH these precursors react with R′OH to give the novel trifluoromethylphosphaalkenes F3CP = C (OR )OR [R /R′: Me/Me (6); E t/E t (7); Me/Et (8)]. With Et2NH , 3 undergoes an addition/elimination process yielding the interesting push/pull system Et2N(F)C = P-CO2Me (5). 1 and 2 react with primary amines R′NH2 (R′= tBu, Me) with stereoselective formation of the fairly labile phosphaalkenes F3CP = C(OR)NHR′ [R /R′: Me/tBu (9), Et/tBu(10), Me/Me (11)] with trans-positions for CF3 and NHR′.The new compounds 3 -11 were characterized by spectroscopic investigations (1H , 19F, 31P, 13C NMR ; IR, MS) and determination of M+ or typical fragment ions [M+ -OR ] by high resolution mass spectrometry.


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