977 research outputs found
A new cross section measurement of reactions induced by 3He-particles on a carbon target
International audienceThe production of intense beams of light radioactive nuclei can be achieved at the SPIRAL2 facility using intense stable beams accelerated by the driver accelerator and impinging on light targets. The isotope 14O is identied to be of high interest for future experiments. The excitation function of the production reaction 12C(3He, n)14O was measured between 7 and 35 MeV. Results are compared with literature data. As an additional result, we report the rst cross-section measurement for the 12C(3He, +n)10C reaction. Based on this new result, the potential in-target 14O yield at SPIRAL2 was estimated: 2.4x1011 pps, for 1 mA of 3He at 35 MeV. This is a factor 140 higher than the in-target yield at SPIRAL1
Thinking through time: From collective memories to collective futures
In this chapter I look at the links between collective memory and the imagination of collective futures. Drawing on works on imagination and autobiographical memory, I first discuss the role of past experiences in imagining the future. I then explore the consequences of such a perspective for collective memories and collective futures, which will lead me to argue that the former provides the basis for the latter. Three case studies are presented, each illustrating a different type of relation between collective memory and collective imagination: 1) collective memory as a frame of reference to imagine the future; 2) collective memory as a source of experiences and examples to imagine what is likely, possible or desirable; and 3) collective memory as generalisable experience from which representations of the world – Personal World Philosophies – are constructed and in turn used to imagine the collective future. This will lead me to the conclusion that representations of the world are characterised by “temporal heteroglossia”, the simultaneous presence of multiple periods of time, and that they mediate the relation between collective memory and collective imagination, allowing us to “think through time”
Probing Nuclear forces beyond the drip-line using the mirror nuclei N and F
Radioactive beams of O and O were used to populate the resonant
states 1/2, 5/2 and in the unbound F and F
nuclei respectively by means of proton elastic scattering reactions in inverse
kinematics. Based on their large proton spectroscopic factor values, the
resonant states in F can be viewed as a core of O plus a proton
in the 2s or 1d shell and a neutron in 1p. Experimental
energies were used to derive the strength of the 2s-1p and
1d-1p proton-neutron interactions. It is found that the former
changes by 40% compared with the mirror nucleus N, and the second by
10%. This apparent symmetry breaking of the nuclear force between mirror nuclei
finds explanation in the role of the large coupling to the continuum for the
states built on an proton configuration.Comment: 6 pages, 3 figures, 2 tables, accepted for publication as a regular
article in Physical Review
New pathway to bypass the 15O waiting point
We propose the sequential reaction process
O(,)O as a new pathway to bypass of the
O waiting point. This exotic reaction is found to have a surprisingly
high cross section, approximately 10 times higher than the
O(,)O. These cross sections were calculated after
precise measurements of energies and widths of the proton-unbound F low
lying states, obtained using the H(O,p)O reaction. The large
cross section can be understood to arise from the more
efficient feeding of the low energy wing of the ground state resonance by the
gamma decay. The implications of the new reaction in novae explosions and X-ray
bursts are discussed.Comment: submitte
Prolate-Spherical Shape Coexistence at N=28 in S
The structure of S has been studied using delayed and
electron spectroscopy at \textsc{ganil}. The decay rates of the 0
isomeric state to the 2 and 0 states have been measured for the
first time, leading to a reduced transition probability
B(E2~:~20= 8.4(26)~efm and a monopole
strength (E0~:~00
=~8.7(7)10. Comparisons to shell model calculations point
towards prolate-spherical shape coexistence and a phenomenological two level
mixing model is used to extract a weak mixing between the two configurations.Comment: 5 pages, 3 figures, accepted for publication in Physical Review
Letter
Best practices for ethical conduct of misinformation research: A scoping review and critical commentary
Misinformation can have noxious impacts on cognition, fostering the formation of false beliefs, retroactively distorting memory for events, and influencing reasoning and decision-making even after it has been credibly corrected. Researchers investigating the impacts of real-world misinformation are therefore faced with an ethical issue: they must consider the immediate and long-term consequences of exposing participants to false claims. In this paper, we first present an overview of the ethical risks associated with real-world misinformation. We then report results from a scoping review of ethical practices in misinformation research. We investigated (1) the extent to which researchers report the details of their ethical practices, including issues of informed consent and debriefing, and (2) the specific steps that researchers report taking to protect participants from the consequences of misinformation exposure. We found that fewer than 30% of misinformation papers report any debriefing, and almost no authors assessed the effectiveness of their debriefing procedure. Building on the findings from this review, we evaluate the balance of risk versus reward currently operating in this field and propose a set of guidelines for best practices. Our ultimate goat is to allow researchers the freedom to investigate questions of considerable scientific and societal impact white meeting their ethical obligations to participants
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