Electromagnetic Properties of Indium Isotopes Elucidate the Doubly Magic Character of ¹⁰⁰Sn

Understanding the nuclear properties in the vicinity of 100Sn – suggested to be the heaviest doubly magic nucleus with equal proton number Z and neutron number N – has been a long-standing challenge for experimental and theoretical nuclear physics. In particular, contradictory experimental evidence exists regarding the role of nuclear collectivity in this region of the nuclear chart. Here, we provide additional evidence for the doubly-magic character of 100Sn by measuring the ground-state electromagnetic moments and nuclear charge radii of indium (Z = 49) isotopes as N approaches 50 from above using precision laser spectroscopy. Our results span almost the complete range between the two major neutron closed shells at N = 50 and N = 82 and reveal parabolic trends as a function of the neutron number, with a clear reduction toward these two neutron closed-shells. A detailed comparison between our experimental and numerical results from two complementary nuclear many-body frameworks, density functional theory and ab initio methods, exposes deficiencies in nuclear models and establishes a benchmark for future theoretical developments.<br/

Challenges for bio-based products in sustainable value chains

This work concerns studies related to strategic development of products in which bio-based plastics are or will be applied, referred to as bio-based products. The studies cover (1) current and potential benefits of bio-based products in extended value chains including activities after end-of-life of products, (2) value communication between stakeholders in extended value chains, and (3) creating an integrated development approach for optimized bio-based products. Most existing models for value chains were found to be one-way single-flow models to which iterations and interactions have been added to obtain realistic representations of best practices. Interviews of thirteen professionals clarified some barriers between the current implementation of bio-based plastics and the ideal sustainable value chain fulfilment. The most noticeable barriers included trustful information sharing, information and knowledge gaps, sub-optimum application of bio-based plastics, and the need for facilitating product design. The main designers' needs are increased integrated literacy related to bio-based materials, eco-effeetiveness and a more effective communication competence in value chains. Based on all findings, six approaches of design tasks integration into value chains have been proposed. These approaches encourage designers to think and act widely across value chains and particularly help implement life cycle thinldng to achieve profitable sustainability.Product Innovatie ManagementIndustrial Design Engineerin

SATLAS2: An update to the package for analysis of counting data

SATLAS2 is a Python library that enables the user to fit counting data from laser spectroscopy experiments, in particular those that measure atomic hyperfine structures. In this analysis, the user can choose how the uncertainties are treated and can also opt to generate a random walk in order to present a fuller picture of the parameter space. The major upgrade compared to the previous version of SATLAS [1] is the different architecture of the codebase, which enabled a performance boost, with speed-up factors ranging from 20 to 300 times for various use cases. For backward compatibility, a translation layer between the two architectures is available, implementing only the core functionality of SATLAS

Development of strategies for the incorporation of microbial pesticides into the integrated management of migratory pests

1 Effective biological pesticides based on oil formulation of deuteromycete fungal spores have been developed for use against locusts and grasshoppers. The isolate IMI 330189 of Metarhizium anisopliae (¯avoviride) var. acridum has been registered, extensively ®eld tested and its operating characteristics explored. It should form an powerful component technology in the integrated management of locust and grasshopper pests. 2 The particular advantages of Metarhizium anisopliae were found to be ef®cacy and persistence, low vertebrate toxicity, little environmental impact, conservation of natural enemies and potential for recycling. Additional socio-economic advantages include the possibility of local production, ease of disposal and versatility in use. The principal disadvantages relate to operating characteristics such as slower speed of kill and slightly greater lability in storage than chemical pesticides. 3 Strategies are being developed to integrate biological control agents into locust and grasshopper management schemes; for Metarhizium the accent is placed on: (i) treating the pest before it invades crops and (ii) situations with a high premium on environmental issues. 4 For some pest situations, fast-acting chemical pesticides will still be necessary for crop protection. 5 A cheaper biological agent, such as Nosema locustae, with the capacity to persist in the pest insect population would be useful. Research is recommended on the long-term impact of Nosema in Africa. 6 An evaluation of the utility of the manual destruction of egg pods leads to the conclusion that we should consider the possibility of importing egg parasitoids, such as Scelio parvicornis from Australia, into Africa. 7 Further development work is needed to clarify the economics and politics of locust and grasshopper control; to improve the regulatory framework for biopesticides; to inform key decision makers of the availability and potential of Metarhizium; and to implement the bio-intensive IPM strategies described

High-precision mass measurement of 168^{168}Yb for verification of nonlinear isotope shift

The absolute mass value of $^{168}$Yb has been directly determined with the JYFLTRAP Penning trap mass spectrometer at the Ion Guide Isotope Separator On-Line (IGISOL) facility. A more precise value of the mass of $^{168}$Yb is needed to extract possible signatures of beyond standard model physics from high-precision isotope shift measurements of Yb atomic transition frequencies. The measured mass-excess value, ME($^{168}$Yb) = $-$61579.846(94) keV, is 12 times more precise and deviates from the Atomic Mass Evaluation 2016 value by 1.7$\sigma$. The impact on precision isotope shift studies of the stable Yb isotopes is discussed

Data from: You are where you live: parasitic nematode mitochondrial genome size is associated with the thermal environment generated by hosts

There exists remarkable interspecific variation in mitochondrial sequence evolution rates and in mitochondrial genome sizes. A number of hypotheses based on the forces of mutation and selection have been proposed to explain this variation. Among such hypotheses, we test three: 1) the ‘longevity-dependent selection’, 2) the ‘functional constraints’ and 3) the ‘race for replication’ hypotheses, using published mtDNA genomic sequences of 47 Nematoda species. We did not find any relationship between body size (used as a proxy for longevity) and genome size or the substitution rate of protein sequences, providing little evidence for the first hypothesis. Parasitic species from different thermal habitats, as determined by their definitive host type (ectothermal vs. endothermal), did not differ in their rates of protein evolution. Therefore, little support was obtained for the second hypothesis. However, we revealed that mitogenomes of parasites of endotherms were significantly smaller than those of parasites of ectotherms, supporting the race for replication hypothesis. As mitochondrial genomes of endothermal animals are usually more compact than those of ectothermal animals, intriguingly, nematode parasites of endotherms and ectotherms exhibit similar patterns of mtDNA length variation to their hosts

First trap-assisted decay spectroscopy of the 81^{81}Ge ground state

The $\beta$-delayed $\gamma$ spectroscopy of $^{81}$As has been performed using a purified beam of $^{81}$Ge $(9/2^+)$ ground state at the Ion Guide Isotope Separator On-Line facility (IGISOL). The $^{81}$Ge$^+$ ions were produced using proton-induced fission of $^{232}$Th and selected with the double Penning trap JYFLTRAP for the post-trap decay spectroscopy measurements. The low-spin $(1/2^+)$ isomeric-state ions $^{81m}\hbox {Ge}^+$ were not observed in the fission products. The intrinsic half-life of the $^{81}$Ge ground state has been determined as $T_{1/2}=6.4(2)~\hbox {s}$, which is significantly shorter than the literature value. A new level scheme of $^{81}$As has been built and is compared to shell-model calculations

Probing the 31Ga_{31}\mathrm{Ga} ground-state properties in the region near Z=28Z=28 with high-resolution laser spectroscopy

International audienceMagnetic-dipole and electric-quadrupole moments for $^{65,67,69,75,79–82}\mathrm{Ga}$ are reported using the Collinear Resonance Ionization Spectroscopy (CRIS) technique at the ISOLDE facility, CERN. The moments of $^{65}\mathrm{Ga}$ have been measured for the first time: $\mu =+1.775(3)\mu_N$ and $Q_s=+21.0(15)e\mathrm{fm}2$. These results are compared to shell-model calculations using the GXPF1 and JUN45 interactions and the trends of the moments approaching the region of the doubly magic $^{56}\mathrm{Ni}$ are discussed. Additionally, new values for the change in mean-square charge radii for $^{65}\mathrm{Ga}$ and $^{67}\mathrm{Ga}$ allow investigation into the odd-even staggering in the region below $N=40$

Precision measurements of the charge radii of potassium isotopes

International audiencePrecision nuclear charge radii measurements in the light-mass region are essential for understanding the evolution of nuclear structure, but their measurement represents a great challenge for experimental techniques. At the Collinear Resonance Ionization Spectroscopy (CRIS) setup at ISOLDE-CERN, a laser frequency calibration and monitoring system was installed and commissioned through the hyperfine spectra measurement of $^{38–47}$K. It allowed for the extraction of the hyperfine parameters and isotope shifts with better than 1 MHz precision. These results are in excellent agreement with available literature values and they demonstrate the suitability of the CRIS technique for the study of nuclear observables in light atomic systems. In addition, the spectral line shapes obtained under different conditions were systematically investigated, highlighting the importance of finding optimal conditions, under which the extracted nuclear properties remain unaffected by laser-atom interactions