In this work we present a keV-scale sterile-neutrino search with a low-tritium-activity data set of the KATRIN experiment, acquired in a commissioning run in 2018. KATRIN performs a spectroscopic ...measurement of the tritium
β
-decay spectrum with the main goal of directly determining the effective electron anti-neutrino mass. During this commissioning phase a lower tritium activity facilitated the measurement of a wider part of the tritium spectrum and thus the search for sterile neutrinos with a mass of up to
1.6
keV
. We do not find a signal and set an exclusion limit on the sterile-to-active mixing amplitude of
sin
2
θ
<
5
×
10
-
4
(
95
%
C.L.) at a mass of 0.3 keV. This result improves current laboratory-based bounds in the sterile-neutrino mass range between 0.1 and 1.0 keV.
The KATRIN experiment is designed for a direct and model-independent determination of the effective electron anti-neutrino mass via a high-precision measurement of the tritium
β
-decay endpoint ...region with a sensitivity on
m
ν
of 0.2
eV
/
c
2
(90% CL). For this purpose, the
β
-electrons from a high-luminosity windowless gaseous tritium source traversing an electrostatic retarding spectrometer are counted to obtain an integral spectrum around the endpoint energy of 18.6 keV. A dominant systematic effect of the response of the experimental setup is the energy loss of
β
-electrons from elastic and inelastic scattering off tritium molecules within the source. We determined the energy-loss function in-situ with a pulsed angular-selective and monoenergetic photoelectron source at various tritium-source densities. The data was recorded in integral and differential modes; the latter was achieved by using a novel time-of-flight technique. We developed a semi-empirical parametrization for the energy-loss function for the scattering of 18.6-keV electrons from hydrogen isotopologs. This model was fit to measurement data with a 95%
T
2
gas mixture at 30 K, as used in the first KATRIN neutrino-mass analyses, as well as a
D
2
gas mixture of 96% purity used in KATRIN commissioning runs. The achieved precision on the energy-loss function has abated the corresponding uncertainty of
σ
(
m
ν
2
)
<
10
-
2
eV
2
1
in the KATRIN neutrino-mass measurement to a subdominant level.
We present the synthesis and structural characterization of a transition metal oxide hydride, LaSrCoO3H0.7, which adopts an unprecedented structure in which oxide chains are bridged by hydride anions ...to form a two-dimensional extended network. The metal centers are strongly coupled by their bonding with both oxide and hydride ligands to produce magnetic ordering at temperatures up to at least 350 kelvin. The synthetic route is sufficiently general to allow the prediction of a new class of transition metal--containing electronic and magnetic materials.
Abstract
Public health information systems have historically been siloed with limited interoperability. The State of Minnesota’s disease surveillance system (Minnesota Electronic Disease Surveillance ...System: MEDSS, ∼12 million total reportable events) and immunization information system (Minnesota Immunization Information Connection: MIIC, ∼130 million total immunizations) lacked interoperability between them and data exchange was fully manual. An interoperability tool based on national standards (HL7 and SOAP/web services) for query and response was developed for electronic vaccination data exchange from MIIC into MEDSS by soliciting stakeholder requirements (n = 39) and mapping MIIC vaccine codes (n = 294) to corresponding MEDSS product codes (n = 48). The tool was implemented in March 2022 and incorporates MIIC data into a new vaccination form in MEDSS with mapping of 30 data elements including MIIC demographics, vaccination history, and vaccine forecast. The tool was evaluated using mixed methods (quantitative analysis of user time, clicks, queries; qualitative review with users). Comparison of key tasks demonstrated efficiencies including vaccination data access (before: 50 clicks, >2 min; after: 4 clicks, 8 s) which translated directly to staff effort (before: 5 h/week; after: ∼17 min/week). This case study demonstrates the contribution of improving public health systems interoperability, ultimately with the goal of enhanced data-driven decision-making and public health surveillance.
Lay Summary
Many of the information systems currently used in public health have limited capabilities to exchange data electronically using nationally recommended standards (also called as interoperability). The Minnesota Department of Health, the state public health agency, uses the Minnesota Electronic Disease Surveillance System (MEDSS) to support disease surveillance, and the Minnesota Immunization Information Connection (MIIC) to support immunization practice and monitoring. The exchange of data between these systems was manual and hence a novel tool for standards-based data exchange was implemented in March 2022. The tool was developed by collecting user needs (n = 39) and mapping MIIC vaccine codes (n = 294) to corresponding MEDSS product codes (n = 48). Currently, 30 vaccination data elements including demographics from MIIC, vaccination history, and vaccine forecast are being imported into MEDSS. The tool was evaluated using quantitative and qualitative methods by assessing user time, clicks, and number of queries and by soliciting feedback from users. Comparison of key tasks demonstrated efficiencies in the access of vaccination data. It took 50 clicks and 5 h/week of staff effort before the tool was available and was decreased to 4 clicks and ∼17 min/week after the tool was implemented. This case study demonstrates the value of improving electronic data exchanges in public health with the goal of better decision-making using data and enhanced public health surveillance.
Near-Zero Thermal Expansion in In(HfMg)0.5Mo3O12 Miller, Kimberly J.; Romao, Carl P.; Bieringer, Mario ...
Journal of the American Ceramic Society,
February 2013, Letnik:
96, Številka:
2
Journal Article
Recenzirano
In(HfMg)0.5Mo3O12, which can be considered as a 1:1 mole ratio solid solution of the low‐positive thermal expansion material HfMgMo3O12 and the low‐negative thermal expansion (NTE) material In2Mo3O12 ...was prepared. From DSC and XRPD results, we show that In(HfMg)0.5Mo3O12 exists in a monoclinic (P21/a) structure at low temperature and undergoes a phase transition at ~425 K to an orthorhombic phase (Pnma), with an associated enthalpy change of 0.89 kJ mol−1. Thermal expansion is large and positive in the low‐temperature monoclinic phase (average αℓ = 16 × 10−6 K−1 and 20 × 10−6 K−1, from dilatometry and XRPD, respectively). Remarkably, this material has a near‐zero thermal expansion (ZTE) coefficient over the temperature range ~500 to ~900 K in the high‐temperature orthorhombic phase, both intrinsically and for the bulk sample. The average linear intrinsic (XRPD) value is αℓ = −0.4 × 10−6 K−1, and the average bulk (dilatometric) value is αℓ = 0.4 × 10−6 K−1 with an uncertainty of ± 0.2 × 10−6 K−1. The slight difference between intrinsic and bulk thermal expansion is attributed to microstructural effects. XRPD results show that the thermal expansion is more isotropic than for the parent compounds HfMgMo3O12 and In2Mo3O12.
A systematic study of the atomic position modulation in polycrystalline CaMn{sub 7}O{sub 12} with different particle sizes (determined from scanning electron microscopy) and crystallite sizes ...(determined from X-ray diffraction) is reported. The morphology and phase composition are characterised by scanning electron microscopy, selected area electron diffraction and energy dispersive X-ray spectroscopy. The crystal structure and the atomic position modulation in polycrystalline CaMn{sub 7}O{sub 12} samples are explored with high-resolution synchrotron radiation based powder X-ray diffraction. The modulation vector and the modulation amplitudes observed at T=10 K do not change as a function of particle size, crystallite size and microstrain fluctuations. In addition, we report and discuss the formation of the additional CaMn{sub 4}O{sub 8} nanowire phase during high temperature annealing. - Graphical abstract: The particle size morphology of the multiferroic CaMn{sub 7}O{sub 12} has a weak influence on the atomic position modulation length and the amplitude of the atomic position modulation below T=250 K. Highlights: Black-Right-Pointing-Pointer Atomic position modulation occurs in CaMn{sub 7}O{sub 12} with different particle sizes. Black-Right-Pointing-Pointer The modulation length is the same for different CaMn{sub 7}O{sub 12} particle sizes. Black-Right-Pointing-Pointer Nanowire shaped crystals of CaMn{sub 4}O{sub 8} can be synthesized.
A systematic study of the atomic position modulation in polycrystalline CaMn7O12 with different particle sizes (determined from scanning electron microscopy) and crystallite sizes (determined from ...X-ray diffraction) is reported. The morphology and phase composition are characterised by scanning electron microscopy, selected area electron diffraction and energy dispersive X-ray spectroscopy. The crystal structure and the atomic position modulation in polycrystalline CaMn7O12 samples are explored with high-resolution synchrotron radiation based powder X-ray diffraction. The modulation vector and the modulation amplitudes observed at T=10K do not change as a function of particle size, crystallite size and microstrain fluctuations. In addition, we report and discuss the formation of the additional CaMn4O8 nanowire phase during high temperature annealing.
The particle size morphology of the multiferroic CaMn7O12 has a weak influence on the atomic position modulation length and the amplitude of the atomic position modulation below T=250K. Display omitted
► Atomic position modulation occurs in CaMn7O12 with different particle sizes. ► The modulation length is the same for different CaMn7O12 particle sizes. ► Nanowire shaped crystals of CaMn4O8 can be synthesized.
Lack of a threefold rotation axis in α‐Fe2O3 and α‐Cr2O3 crystals Stękiel, Michał; Przeniosło, Radosław; Sosnowska, Izabela ...
Acta crystallographica Section B, Structural science, crystal engineering and materials,
April 2015, 2015-Apr, 20150401, Letnik:
71, Številka:
2
Journal Article
Recenzirano
The crystal structure of α‐Fe2O3 and α‐Cr2O3 is usually described with the corundum‐type trigonal crystal structure based on the space group . There are, however, some observations of the magnetic ...ordering of both α‐Fe2O3 and α‐Cr2O3 that are incompatible with the trigonal symmetry. We show experimental evidence based on X‐ray powder diffraction and supported by transmission electron microscopy that the symmetry of the crystal structure of both α‐Fe2O3 and α‐Cr2O3 is monoclinic and it is described with the space group C2/c (derived from by removing the threefold rotation axis). The magnetic orderings of α‐Fe2O3 and α‐Cr2O3 are compatible with the magnetic space groups C2/c and C2/c′, respectively. These findings are in agreement with the idea from Curie (1894), J. Phys.3, 393–415 that the dissymmetry of the magnetic ordering should be associated with a dissymmetry of the crystal structure.
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