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Rare‐Earth Reduction in High‐Speed PM‐Assisted Synchronous Reluctance Motors Using Hybrid Magnet Strategies and Design Optimisation for 800 V EVs
The trend towards electrifying transportation systems has stimulated research endeavours aimed at developing electric machines that are not only high speed and efficient but also low‐cost and compact. To support this transition, the US Department of Energy (DOE) has established ambitious targets of $7/kW cost and 12 kW/L power density for the electric drivetrains. This paper attempts to meet these targets by proposing high‐speed permanent magnet assisted synchronous reluctance machine (PMASynRM) topologies enabled by hybrid magnet strategies, combining rare‐earth (RE) magnets with low‐cost, RE‐free alternatives. Modified 2‐layer and 3‐layer U‐shaped rotor configurations, featuring structural reinforcements to withstand high mechanical stress at elevated speeds, are developed. A multi‐objective design optimisation framework is employed to optimise the rotor design, targeting reductions in RE magnet volume, magnet demagnetisation risk and torque ripple while achieving the desired electromagnetic performance. A comprehensive analysis of the optimised rotor designs, compared against a 16,000 rpm, 800 V baseline IPM motor, shows over 70% RE reduction, demagnetisation risk below 3.5% and torque ripple under 10%. Detailed analyses of performance trends across various magnet combinations and rotor configurations highlight the viability of hybrid magnet PMASynRM designs as cost‐effective, robust and energy‐efficient solutions for next‐generation EVs.
Development and validation of a humidified CAPS-PM SSA with an improved methodology to calculate the truncation correction factor
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Development of ASTM International D8405—Standard Test Method for Evaluating PM 2.5 Sensors or Sensor Systems Used in Indoor Applications
Sensors and sensor systems for monitoring fine particles with aerodynamic diameters smaller than 2.5 µm can provide real-time feedback on indoor air quality and thus can help guide actions to manage indoor air pollutant concentrations. Standardized verification of the performance and accuracy of sensors and sensor systems is crucial for predicting the efficacy of such monitoring. A new ASTM International standard test method (ASTM D8405) was created for this need and is the most exacting laboratory protocol published to date for evaluating indoor air quality sensors and sensor systems measuring particles smaller than 2.5 µm in diameter. ASTM D8405 subjects sensors and sensor systems to five test phases: (1) an initial particle concentration ramp; (2) exposure to various temperature and humidity conditions; (3) exposure to interfering particles; (4) temperature cycling; and (5) a final particle concentration ramp to assess drift. This paper discusses the development of the standard test method, key aspects of the testing process, example evaluation results, and a comparison of this standard test method against peer evaluation protocols.
Search for a light charged Higgs boson in the H$^\pm$ $\to $ cs channel in proton-proton collisions at $\sqrt{s} =$ 13 TeV
A search is conducted for a low-mass charged Higgs boson produced in a top quark decay and subsequently decaying into a charm and a strange quark. The data sample was recorded in proton-proton collisions at s=13 TeV by the CMS experiment at the LHC and corresponds to an integrated luminosity of 35.9 fb-1. The search is performed in the process of top quark pair production, where one top quark decays to a bottom quark and a charged Higgs boson and the other to a bottom quark and a W boson. With the W boson decaying to a charged lepton (electron or muon) and a neutrino, the final state comprises an isolated lepton, missing transverse momentum, and at least four jets, of which two are tagged as b jets. To enhance the search sensitivity, one of the jets originating from the charged Higgs boson is required to satisfy a charm tagging selection. No significant excess beyond standard model predictions is found in the dijet invariant mass distribution. An upper limit in the range 1.68%–0.25% is set on the branching fraction of the top quark decay to the charged Higgs boson and bottom quark for a charged Higgs boson mass between 80 and 160 GeV.
Optimal Design of Spoke-Type IPM Motor Allowing Irreversible Demagnetization to Minimize PM Weight
Not Available
Search for heavy neutral leptons in $W^+\rightarrow \mu ^{+}\mu ^{\pm }\, \text {jet}$ decays
A search is performed for heavy neutrinos in the decay of a W boson into two muons and a jet. The data set corresponds to an integrated luminosity of approximately 3.0fb –1 of proton–proton collision data at centre-of-mass energies of 7 and 8 TeV collected with the LHCb experiment. Both same-sign and opposite-sign muons in the final state are considered. Data are found to be consistent with the expected background. Upper limits on the coupling of a heavy neutrino with the Standard Model neutrino are set at 95% confidence level in the heavy-neutrino mass range from 5 to 50GeV/c 2 . These are of the order of 10 –3 for lepton-number-conserving decays and of the order of 10 –4 for lepton-number-violating heavy-neutrino decays.
$\Sigma (1385)^{\pm }$ resonance production in Pb–Pb collisions at $\sqrt{s_{\textrm{NN}}} = 5.02$ TeV
Hadronic resonances are used to probe the hadron gas produced in the late stage of heavy-ion collisions since they decay on the same timescale, of the order of 1–10 fm/c, as the decoupling time of the system. In the hadron gas, (pseudo)elastic scatterings among the products of resonances that decayed before the kinetic freeze-out and regeneration processes counteract each other, the net effect depending on the resonance lifetime, the duration of the hadronic phase, and the hadronic cross sections at play. In this context, the Σ(1385) ± particle is of particular interest as models predict that regeneration dominates over rescattering despite its relatively short lifetime of about 5.5 fm/c. The first measurement of the Σ(1385) ± resonance production at midrapidity in Pb–Pb collisions at $\sqrt{s_{NN}}$=5.02 TeV with the ALICE detector is presented in this Letter. The resonances are reconstructed via their hadronic decay channel, Λπ, as a function of the transverse momentum (p T ) and the collision centrality. The results are discussed in comparison with the measured yield of pions and with expectations from the statistical hadronization model as well as commonly employed event generators, including PYTHIA8/Angantyr and EPOS3 coupled to the UrQMD hadronic cascade afterburner. None of the models can describe the data. For Σ(1385) ± , a similar behaviour as K*(892) 0 is observed in data unlike the predictions of EPOS3 with afterburner.
Early Application Results on Pre-exascale Architecture with Analysis of Performance Challenges and Projections (Milestone PM-AD-1080 WBS 2.2)
This Exascale Computing Project (ECP) Milestone Report summarizes the status of all 30 ECP Applications Development (AD) sub-projects at the end of FY19. In August and September of 2019, a comprehensive assessment of AD projects was conducted jointly by the ECP leadership and a team of external subject matter experts. Reviews took place in person over five days-two at the National Renewable Energy Laboratory and three at Argonne National Laboratory and the University of Chicago. The review committees were tasked with evaluating each sub-project's progress in porting their code(s) to current multi-GPU architectures considered precursors to planned exascale machines. This includes characterizing which modules have been ported to multi-accelerator nodes, initial performance analyses, the status of software integration, and a current vision of successes, obstacles, and next steps. As such this report contains not only an accurate snapshot of each sub-project's current status, but also represents an unprecedentedly broad account of experiences porting large scientific applications to next-generation HPC architectures.
Latest Developments in PM Systems and Methods and their Application to WM Projects - 20364
How do you improve on an industry that is well established yet often misses the mark on key metrics demonstrating effective planning and execution of project scope, schedule and budget? With the increased complexity of DOE projects relative to either poorly kept records of what wastes are stored or the lack of specific knowledge relative to the waste concentrations/quantities, this is a question continually asked and investigated by many. In fact, in 2017, the GAO's report to Congress indicated that although the DOE has made some progress on its monitoring effectiveness and demonstrating progress criteria, these goals were not met and there needs to be more improvement and monitoring. This paper will offer some insights into the latest developments in project management methodologies and the possible application of these to waste management projects. Traditional data generated via a project schedule that utilizes critical path methodology (CPM) and additional earned value management (EVM) data needs to be accurate and enable the project manager to better understand the probability of project success. Although this data has readily been available on most large-scale projects, success as measured by various stakeholder groups including the client, project team, regulators, etc. is less than optimal. Therefore, an urgent need exists to explore how traditional project data (CPM and EVM) coupled with new methodologies allows for better planning and execution by the project team. Many new approaches/methodologies can even be used to predict the success of options prior to full implementation on the actual project. Three approaches/methodologies will be discussed: - Artificial Intelligence; - Change Management; - Blend of Traditional Management (Gantt chart) and Agile Methodologies. As market forces change, so will the direction of project management. The days of 'one size fits all' are no longer valid. A combination of predictive and adaptive approaches in the management of projects is essential to enable execution of project deliverables on time, under budget, and within the contractual scope. This paper is intended to provide the reader with insight to the close relationship of project management trends and business management trends, and to provoke critical thinking about what it means to align project management strategy with an environment of non-stop innovation. (authors)
Investigation of large-scale AM + PM parts for Nuclear Application
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Materials Data on Pm5Mg by Materials Project
MgPm5 crystallizes in the orthorhombic Amm2 space group. The structure is three-dimensional. Mg is bonded in a 10-coordinate geometry to ten Pm atoms. There are a spread of Mg–Pm bond distances ranging from 3.47–3.61 Å. There are five inequivalent Pm sites. In the first Pm site, Pm is bonded to twelve Pm atoms to form PmPm12 cuboctahedra that share corners with eighteen PmPm12 cuboctahedra, edges with ten PmPm10Mg2 cuboctahedra, and faces with eighteen PmPm12 cuboctahedra. There are a spread of Pm–Pm bond distances ranging from 3.56–3.73 Å. In the second Pm site, Pm is bonded to four equivalent Mg and eight Pm atoms to form a mixture of distorted corner, edge, and face-sharing PmPm8Mg4 cuboctahedra. There are a spread of Pm–Pm bond distances ranging from 3.47–3.71 Å. In the third Pm site, Pm is bonded to two equivalent Mg and ten Pm atoms to form a mixture of corner, edge, and face-sharing PmPm10Mg2 cuboctahedra. There are four shorter (3.54 Å) and two longer (3.71 Å) Pm–Pm bond lengths. In the fourth Pm site, Pm is bonded to two equivalent Mg and ten Pm atoms to form distorted PmPm10Mg2 cuboctahedra that share corners with twelve PmPm10Mg2 cuboctahedra, edges with fifteen PmPm12 cuboctahedra, and faces with eighteen PmPm12 cuboctahedra. All Pm–Pm bond lengths are 3.71 Å. In the fifth Pm site, Pm is bonded to two equivalent Mg and ten Pm atoms to form distorted PmPm10Mg2 cuboctahedra that share corners with twelve PmPm10Mg2 cuboctahedra, edges with fifteen PmPm8Mg4 cuboctahedra, and faces with eighteen PmPm12 cuboctahedra. Both Pm–Pm bond lengths are 3.71 Å.
Precise measurements of branching fractions for $ {\mathrm{D}}_{\mathrm{s}}^{+} $ meson decays to two pseudoscalar mesons
We measure the branching fractions for seven $D$$^{+}_{s}$ two-body decays to pseudo-scalar mesons, by analyzing data collected at √s = 4.178 ~ 4.226 GeV with the BESIII detector at the BEPCII collider. The branching fractions are determined to be $$ {\displaystyle \begin{array}{c}\mathcal{B}\left({D}_s^{+}\to {K}^{+}\eta \hbox{'}\right)=\left(2.68\pm 0.17\pm 0.17\pm 0.08\right)\times {10}^{-3},\\ {}\mathcal{B}\left({D}_s^{+}\to \eta \hbox{'}{\pi}^{+}\right)=\left(37.8\pm 0.4\pm 2.1\pm 1.2\right)\times {10}^{-3},\\ {}\mathcal{B}\left({D}_s^{+}\to {K}^{+}\eta \right)=\left(1.62\pm 0.10\pm 0.03\pm 0.05\right)\times {10}^{-3},\\ {}\mathcal{B}\left({D}_s^{+}\to \eta {\pi}^{+}\right)=\left(17.41\pm 0.18\pm 0.27\pm 0.54\right)\times {10}^{-3},\\ {}\mathcal{B}\left({D}_s^{+}\to {K}^{+}{K}_S^0\right)=\left(15.02\pm 0.10\pm 0.27\pm 0.47\right)\times {10}^{-3},\\ {}\mathcal{B}\left({D}_s^{+}\to {K}_S^0{\pi}^{+}\right)=\left(1.109\pm 0.034\pm 0.023\pm 0.035\right)\times {10}^{-3},\\ {}\mathcal{B}\left({D}_s^{+}\to {K}^{+}{\pi}^0\right)=\left(0.748\pm 0.049\pm 0.018\pm 0.035\right)\times {10}^{-3},\end{array}} $$ B D s + → K + η ' = 2.68 ± 0.17 ± 0.17 ± 0.08 × 10 - 3 , B D s + → η ' π + = 37.8 ± 0.4 ± 2.1 ± 1.2 × 10 - 3 , B D s + → K + η = 1.62 ± 0.10 ± 0.03 ± 0.05 × 10 - 3 , B D s + → η π + = 17.41 ± 0.18 ± 0.27 ± 0.54 × 10 - 3 , B D s + → K + K S 0 = 15.02 ± 0.10 ± 0.27 ± 0.47 × 10 - 3 , B D s + → K S 0 π + = 1.109 ± 0.034 ± 0.023 ± 0.035 × 10 - 3 , B D s + → K + π 0 = 0.748 ± 0.049 ± 0.018 ± 0.035 × 10 - 3 , where the first uncertainties are statistical, the second are systematic, and the third are from external input branching fraction of the normalization mode $ {D}_s^{+} $ D s + → K + K - π + . Precision of our measurements is significantly improved compared with that of the current world average values.
Materials Data on AcPm3 by Materials Project
AcPm3 is Magnesium-derived structured and crystallizes in the hexagonal P6_3/mmc space group. The structure is three-dimensional. Ac is bonded to twelve Pm atoms to form AcPm12 cuboctahedra that share corners with six equivalent AcPm12 cuboctahedra, corners with twelve PmAc4Pm8 cuboctahedra, edges with eighteen PmAc4Pm8 cuboctahedra, faces with eight equivalent AcPm12 cuboctahedra, and faces with twelve PmAc4Pm8 cuboctahedra. There are six shorter (3.75 Å) and six longer (3.78 Å) Ac–Pm bond lengths. There are three inequivalent Pm sites. In the first Pm site, Pm is bonded to four equivalent Ac and eight Pm atoms to form PmAc4Pm8 cuboctahedra that share corners with four equivalent AcPm12 cuboctahedra, corners with fourteen PmAc4Pm8 cuboctahedra, edges with six equivalent AcPm12 cuboctahedra, edges with twelve PmAc4Pm8 cuboctahedra, faces with four equivalent AcPm12 cuboctahedra, and faces with sixteen PmAc4Pm8 cuboctahedra. There are a spread of Pm–Pm bond distances ranging from 3.67–3.84 Å. In the second Pm site, Pm is bonded to four equivalent Ac and eight Pm atoms to form PmAc4Pm8 cuboctahedra that share corners with four equivalent AcPm12 cuboctahedra, corners with fourteen PmAc4Pm8 cuboctahedra, edges with six equivalent AcPm12 cuboctahedra, edges with twelve PmAc4Pm8 cuboctahedra, faces with four equivalent AcPm12 cuboctahedra, and faces with sixteen PmAc4Pm8 cuboctahedra. There are a spread of Pm–Pm bond distances ranging from 3.67–3.84 Å. In the third Pm site, Pm is bonded to four equivalent Ac and eight Pm atoms to form PmAc4Pm8 cuboctahedra that share corners with four equivalent AcPm12 cuboctahedra, corners with fourteen PmAc4Pm8 cuboctahedra, edges with six equivalent AcPm12 cuboctahedra, edges with twelve PmAc4Pm8 cuboctahedra, faces with four equivalent AcPm12 cuboctahedra, and faces with sixteen PmAc4Pm8 cuboctahedra. There are one shorter (3.67 Å) and one longer (3.84 Å) Pm–Pm bond lengths.
Materials Data on CsPm by Materials Project
CsPm is Copper-derived structured and crystallizes in the trigonal R-3m space group. The structure is three-dimensional. there are three inequivalent Cs sites. In the first Cs site, Cs is bonded to six equivalent Cs and six equivalent Pm atoms to form CsCs6Pm6 cuboctahedra that share corners with twelve CsCs6Pm6 cuboctahedra, edges with twelve CsCs6Pm6 cuboctahedra, edges with twelve equivalent PmCs6Pm6 cuboctahedra, faces with six equivalent CsCs6Pm6 cuboctahedra, and faces with twelve equivalent PmCs6Pm6 cuboctahedra. All Cs–Cs bond lengths are 3.89 Å. All Cs–Pm bond lengths are 4.45 Å. In the second Cs site, Cs is bonded to six equivalent Cs and six Pm atoms to form CsCs6Pm6 cuboctahedra that share corners with five equivalent PmCs6Pm10 cuboctahedra, corners with twelve CsCs6Pm6 cuboctahedra, edges with ten PmCs6Pm6 cuboctahedra, edges with twelve CsCs6Pm6 cuboctahedra, faces with six equivalent CsCs6Pm6 cuboctahedra, and faces with fifteen PmCs6Pm6 cuboctahedra. All Cs–Cs bond lengths are 3.89 Å. All Cs–Pm bond lengths are 4.45 Å. In the third Cs site, Cs is bonded to six equivalent Cs and six Pm atoms to form CsCs6Pm6 cuboctahedra that share corners with five equivalent PmCs6Pm10 cuboctahedra, corners with twelve CsCs6Pm6 cuboctahedra, edges with ten PmCs6Pm6 cuboctahedra, edges with twelve CsCs6Pm6 cuboctahedra, faces with six equivalent CsCs6Pm6 cuboctahedra, and faces with fifteen PmCs6Pm6 cuboctahedra. All Cs–Cs bond lengths are 3.89 Å. All Cs–Pm bond lengths are 4.45 Å. There are two inequivalent Pm sites. In the first Pm site, Pm is bonded to six Cs and six equivalent Pm atoms to form PmCs6Pm6 cuboctahedra that share corners with twelve PmCs6Pm6 cuboctahedra, edges with twelve CsCs6Pm6 cuboctahedra, edges with twelve PmCs6Pm6 cuboctahedra, faces with six equivalent PmCs6Pm6 cuboctahedra, and faces with twelve CsCs6Pm6 cuboctahedra. All Pm–Pm bond lengths are 3.89 Å. In the second Pm site, Pm is bonded to six Cs and ten equivalent Pm atoms to form PmCs6Pm10 cuboctahedra that share corners with ten CsCs6Pm6 cuboctahedra, corners with twelve PmCs6Pm6 cuboctahedra, edges with eight CsCs6Pm6 cuboctahedra, edges with sixteen PmCs6Pm6 cuboctahedra, faces with sixteen equivalent PmCs6Pm10 cuboctahedra, and faces with eighteen CsCs6Pm6 cuboctahedra. There are a spread of Pm–Pm bond distances ranging from 3.89–7.77 Å.
Measurements of the branching fractions of ${\Xi }_{c}^{+}\to {\Sigma }^{+}{K}_{S}^{0}$, ${\Xi }_{c}^{+}\to {\Xi }^{0}{\pi }^{+}$, and ${\Xi }_{c}^{+}\to {\Xi }^{0}{K}+$ at Belle and Belle II
Using 983.0 fb −1 and 427.9 fb −1 data samples collected with the Belle and Belle II detectors at the KEKB and SuperKEKB asymmetric energy e + e − colliders, respectively, we present studies of the Cabibbo-favored ${\Xi }_{c}^{+}$ decays ${\Xi }_{c}^{+}\to {\Sigma }^{+}{K}_{S}^{0}$ and ${\Xi }_{c}^{+}\to {\Xi }^{0}{\pi }^{+}$, and the singly Cabibbo-suppressed decay ${\Xi }_{c}^{+}\to {\Xi }^{0}{K}^{+}$. The ratios of branching fractions of ${\Xi }_{c}^{+}\to {\Sigma }^{+}{K}_{S}^{0}$ and ${\Xi }_{c}^{+}\to {\Xi }^{0}{K}^{+}$ relative to that of ${\Xi }_{c}^{+}\to {\Xi }^{-}{\pi }^{+}{\pi }^{+}$ are measured for the first time, while the ratio $\mathcal{B}({\Xi }_{c}^{+}\to {\Xi }^{0}{\pi }^{+})/\mathcal{B}({\Xi }_{c}^{+}\to {\Xi }^{-}{\pi }^{+}{\pi }^{+})$ is also determined and improved by an order of magnitude in precision. The measured branching fraction ratios are $\begin{array}{c}\frac{\mathcal{B}\left({\Xi }_{c}^{+}\to {\Sigma }^{+}{K}_{S}^{0}\right)}{\mathcal{B}\left({\Xi }_{c}^{+}\to {\Xi }^{-}{\pi }^{+}{\pi }^{+}\right)}=0.067\pm 0.007\pm 0.003,\\ \frac{\mathcal{B}\left({\Xi }_{c}^{+}\to {\Xi }^{0}{\pi }^{+}\right)}{\mathcal{B}\left({\Xi }_{c}^{+}\to {\Xi }^{-}{\pi }^{+}{\pi }^{+}\right)}=0.251\pm 0.005\pm 0.010,\\ \frac{\mathcal{B}\left({\Xi }_{c}^{+}\to {\Xi }^{0}{K}^{+}\right)}{\mathcal{B}\left({\Xi }_{c}^{+}\to {\Xi }^{-}{\pi }^{+}{\pi }^{+}\right)}=0.017\pm 0.003\pm 0.001.\end{array}$ Additionally, the ratio $\mathcal{B}({\Xi }_{c}^{+}\to {\Xi }^{0}{K}^{+})/\mathcal{B}({\Xi }_{c}^{+}\to {\Xi }^{0}{\pi }^{+})$ is measured to be 0.068 ± 0.010 ± 0.004. Here, the first and second uncertainties are statistical and systematic, respectively. Multiplying the ratios by the branching fraction of the normalization mode, $\mathcal{B}({\Xi }_{c}^{+}\to {\Xi }^{-}{\pi }^{+}{\pi }^{+})=(2.9\pm 1.3)%$, we obtain the following absolute branching fractions $\begin{array}{c}\mathcal{B}({\Xi }_{c}^{+}\to {\Sigma }^{+}{K}_{S}^{0})=(0.194\pm 0.021\pm 0.009\pm 0.087)\text{%},\\ \mathcal{B}({\Xi }_{c}^{+}\to {\Xi }^{0}{\pi }^{+})=(0.728\pm 0.014\pm 0.027\pm 0.326)\text{%},\\ \mathcal{B}({\Xi }_{c}^{+}\to {\Xi }^{0}{K}^{+})=(0.049\pm 0.007\pm 0.003\pm 0.022)\text{%},\end{array}$ where the third uncertainties are from $\mathcal{B}({\Xi }_{c}^{+}\to {\Xi }^{-}{\pi }^{+}{\pi }^{+})$.