Search results for "Product yield"

The aminophosphonate glyphosine enhances phycobiliprotein yields from selected cyanobacterial cultures

2017

Among added-value products obtained from cyanobacterial cultures are phycobiliproteins, photosynthetic pigments that have found an increasing number of applications as natural dyes for food, cosmetics, pharmaceuticals, and antioxidants. To obtain sustainable production, we aimed at maximizing phycobilin yield through the increase of either the final biomass or the specific content of these pigments by varying culture parameters, such as chemical composition and pH of the medium or quality and intensity of the light. Here, we report that the addition to the culture medium of millimolar or submillimolar concentrations of the aminophosphonate glyphosine [(N,N-bis(phosphonomethyl)glycine], form…

Mass-asymmetric fission in the 40ca+142Nd reaction

2016

Shell effects play a major role in fission. Mass-asymmetric fission observed in the spontaneous and low energy fission of actinide nuclei was explained by incorporating the fragment shell properties in liquid drop model. Asymmetric fission has also been observed in the low energy fission of neutron-deficient 180 Hg nuclei in recent β -delayed fission experiments. This low-energy β -delayed fission has been explained in terms of strong shell effects in pre-scission configurations associated with the system after capture. Calculations predicted asymmetric fission for heavier Hg isotopes as well, at compound nuclear excitation energy as high as 40 MeV. To explore the evolution of fission fragm…

Isomeric Yield Ratios of 134I and 136I and Independent Fractional Yields of some Halogen Isotopes in the Fission of 232Th with Reactor Neutrons

1990

A ROOT-based analysis tool for measurements of neutron-induced fission products at the IGISOL facility

2012

For the sustainable development of nuclear energy, the handling of used nuclear fuel is a key issue. Innovative fuel cycles are being developed for the transmutation of minor actinides and long-lived fission products. In view of these developments, accurate knowledge of the fuel inventory is necessary. The IGISOL facility with JYFLTRAP, at the accelerator laboratory of the University of Jyvaskyla, will be used to measure independent fission yield distributions from neutron-induced fission on different actinides. In this paper, an analysis tool is developed, using the CERN-based ROOT Data Analysis Framework, with the objective of performing full data analysis within the same code. The analys…

Fission studies at IGISOL/JYFLTRAP: Simulations of the ion guide for neutron-induced fission and comparison with experimental data

2020

For the production of exotic nuclei at the IGISOL facility, an ion guide for neutron-induced fission has been developed and tested in experiments. Fission fragments are produced inside the ion guide and collected using a helium buffer gas. Meanwhile, a GEANT4 model has been developed to simulate the transportation and stopping of the charged fission products. In a recent measurement of neutron-induced fission yields, implantation foils were located at different positions in the ion guide. The gamma spectra from these foils and the fission targets are compared to the results from the GEANT4 simulation. In order to allow fission yield measurements in the low yield regions, towards the tails a…

Experimental study of the pyrolysis of waste bitumen for oil production

2020

Abstract This work focuses on bitumen slow pyrolysis. Mass and energy yields of oil, solid and gas were obtained from pyrolysis experiments using a semi-batch reactor in a nitrogen atmosphere, under three non-isothermal conditions (maximum temperature: 450 °C, 500 °C and 550 °C). The effect of temperature on the product yields was discussed. The gas compositions were analysed using gas chromatography (GC) and the heating value of oil and solid residue was also measured. Using a thermo-gravimetric analyser, kinetic parameters were evaluated through Ozawa-Flynn-Wall (OFW) method. Results showed that oil yield is maximum at 500 °C (50%). Moreover, gas yield increased with increasing pyrolysis …

Isomeric fission yield ratios for odd-mass Cd and In isotopes using the Phase-Imaging Ion-Cyclotron-Resonance technique

2018

Isomeric yield ratios for the odd-$A$ isotopes of $^{119-127}$Cd and $^{119-127}$In from 25-MeV proton-induced fission on natural uranium have been measured at the JYFLTRAP double Penning trap, by employing the Phase-Imaging Ion-Cyclotron-Resonance technique. With the significantly improved mass resolution of this novel method isomeric states separated by 140 keV from the ground state, and with half-lives of the order of 500 ms, could be resolved. This opens the door for obtaining new information on low-lying isomers, of importance for nuclear structure, fission and astrophysics. In the present work the experimental isomeric yield ratios are used for the estimation of the root-mean-square a…

Separation of fission products by the ion guide fed isotope separator, IGISOL

1987

Abstract The performance of the ion guide method in the on-line mass separation of fission products has been investigated. Activity was produced by bombarding nat. U targets with a beam of 20 MeV protons. All the mass chains from A = 95 through A = 120 have been scanned using conventional methods of nuclear spectroscopy. No chemical selectivity in the separation was observed; isotopes of highly nonvolatile elements from yttrium to palladium were produced with efficiencies equal to those for the more volatile ones. The boundary of known neutron-rich nuclides was reached throughout the mass region from A = 106 to A = 118. During the course of this preliminary study the new isotope 116 Rh was …

Developments for neutron-induced fission at IGISOL-4

2016

At the IGISOL-4 facility, neutron-rich, medium mass nuclei have usually been produced via charged particle-induced fission of natural uranium and thorium. Neutron-induced fission is expected to have a higher production cross section of the most neutron-rich species. Development of a neutron source along with a new ion guide continues to be one of the major goals since the commissioning of IGISOL-4. Neutron intensities at di↵erent angles from a beryllium neutron source have been measured in an on-line experiment with a 30 MeV proton beam. Recently, the new ion guide coupled to the neutron source has been tested as well. Details of the neutron source and ion guide design together with prelimi…

Delayed-neutrons from arsenic isotopes 84As, 85As and 86As

1973

Abstract Short-lived arsenic isotopes were produced by thermal-neutron fission of 235U and isolated within 2·5 sec by volatilization of arsenic hydride. The existence of a strong delayed-neutron precursor of 2·05±0·05 sec half-life among the arsenic isotopes is confirmed and its assignment to 85As ascertained by milking of the daughter product 33 sec 85Se and 3·1 min 84Se, which is the final nucleus in the neutron decay branch of 85As. A delayed-neutron yield of 7·8 ± 1·2 neutrons/104 fissions was obtained for 85As. A new isotope, 0·9 ± 0·2 sec 86As, was detected by delayed-neutron counting and by following the decay of its most prominent γ-ray. The mass assignment was verified by milking o…