An all-solid-state lithium-ion battery with sulfide solid electrolyte is expected to be operated and fabricated under pressure to achieve high ionic conductivity. However, the varying mechanical ...properties of the constituent materials of composite electrodes generate a non-uniform stress distribution, which affects the ionic conductivity. Moreover, because of the presence of various active materials with different Young's moduli, the correlation between the Young's modulus of the active material and ion-conduction characteristics of a composite electrode is considered. In this study, to elucidate the effect of the Young's modulus of the active material on the ionic conductivity of a composite electrode, electrochemical impedance spectroscopy measurements and finite element method stress simulations based on X-ray computed tomography images are performed for model composite electrodes. The model composite electrodes are fabricated by mixing the solid electrolyte with zirconia or nylon in different volumetric fractions. The experimental results demonstrate that a composite electrode containing an active material with lower Young's modulus exhibits a higher ionic conductivity and lower saturation pressure. The finite element method stress simulation indicates that the change in the ion-conduction characteristics originates from the stress concentration induced by the active material's Young's modulus and volumetric fraction.
•EIS and X-ray CT measurements of composite electrodes are conducted.•The stress inside a composite electrode is analyzed using voxel-based FEM.•Stress concentrates in a material with higher Young's modulus.•The active material alters the saturation pressure of composite electrodes.•The ionic conduction is affected by the Young's modulus of the active materials.
PD-L1 (programmed cell death 1 ligand 1) on tumour cells suppresses host immunity through binding to its receptor PD-1 on lymphocytes, and promotes peritoneal dissemination in mouse models of ovarian ...cancer. However, how PD-L1 expression is regulated in ovarian cancer microenvironment remains unclear.
The number of CD8-positive lymphocytes and PD-L1 expression in tumour cells was assessed in ovarian cancer clinical samples. PD-L1 expression and tumour progression in mouse models under conditions of altering IFN-γ signals was assessed.
The number of CD8-positive cells in cancer stroma was very high in peritoneally disseminated tumours, and was strongly correlated to PD-L1 expression on the tumour cells (P<0.001). In mouse models, depleting IFNGR1 (interferon-γ receptor 1) resulted in lower level of PD-L1 expression in tumour cells, increased the number of tumour-infiltrating CD8-positive lymphocytes, inhibition of peritoneal disseminated tumour growth and longer survival (P=0.02). The injection of IFN-γ into subcutaneous tumours induced PD-L1 expression and promoted tumour growth, and PD-L1 depletion completely abrogated tumour growth caused by IFN-γ injection (P=0.01).
Interferon-γ secreted by CD8-positive lymphocytes upregulates PD-L1 on ovarian cancer cells and promotes tumour growth. The lymphocyte infiltration and the IFN-γ status may be the key to effective anti-PD-1 or anti-PD-L1 therapy in ovarian cancer.
High-pressure in situ three-dimensional structural measurements using X-ray computed tomography and electrochemical impedance spectroscopy measurement of a sulfide solid electrolyte are conducted to ...elucidate the influence of the nanoscale structure on its ionic conductivity. Computed tomography image-based three-dimensional numerical simulations are conducted to assess the ion-transportation phenomena. The results show that high-pressure in situ X-ray computed tomography can successfully enable visualization of crushing of the solid electrolyte particles and room-temperature pressure sintering. The ionic conductivity increases with an increase in applied pressure. The densified state achieved by room-temperature pressure sintering is maintained even after the applied pressure is decreased. The experimentally measured impedances are in close agreement with the computed tomography image-based numerical simulation results. This finding suggests that effects of internal stress on the contact resistance between sulfide solid electrolyte particles and their ionic conductivity are negligibly small. Furthermore, at small scale, ion-transportation characteristics can be estimated by the three-dimensional distribution of sulfide solid electrolyte and pores. The experiments and numerical simulations are conducted for various sulfide solid electrolytes, and these characteristics are found to be valid for all tested materials.
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•The compression characteristics of a sulfide solid electrolyte are discussed.•High pressure in situ X-ray CT and EIS measurements are conducted.•The numerical simulation results are in close agreement with experimental results.•The contact resistance between SE particles is negligibly small.•The ionic conductivity can be calculated from the distribution of SE and void.
The transversely polarized target (PT) of the COMPASS (NA58) collaboration at CERN has been used for Drell–Yan measurements in 2015 and 2018. The transverse spin structure of the proton has been ...studied using a negative pion beam and a solid ammonia target. Employing the dynamic nuclear polarization (DNP) method, proton polarization values of more than 80% have been routinely achieved after one day, at a homogeneous magnetic field of 2.5 T and using a 3He/4He dilution refrigerator. During the data-taking the target operates in a transversely oriented magnetic dipole field at 0.6 T. This so-called frozen spin operation mode without the DNP pumping process leads to a slow depolarization of the target material, which is further accelerated by the heat input of the pion beam, produced secondary particles and radiation damage effects to the target material. Ammonia has the highest resistance against radiation-induced depolarization among known solid target materials. The proton polarization has been measured by the nuclear magnetic resonance (NMR). Relaxation times of about 1100 h have been observed for the proton polarization resulting in an average polarization between 68% and 76% during about two weeks long data-taking periods. To achieve a systematic uncertainty of the polarization ΔP/P as low as 3.2% and a statistical one of less than 1.8% two large target cells with appropriate positioning of the NMR-coils have been built.
An accurate analysis of ion transportation in an all-solid-state battery is crucial to improve and estimate performance. For an all-solid-state battery using sulfide solid electrolytes, coupling the ...stress and electric field simulations is required because the battery is pressurized, this affects the void space, which then affects ion transportation. In this paper, we propose a new method to analyze the ionic conductivity in a pressurized all-solid-state battery by coupling nonlinear stress analysis and electric field analysis. The nonlinear stress analysis can estimate the stress distribution of solid electrolyte and it was found that nonlinear stress-strain characteristics that originate from the voids diminished with increased pressure. The numerical results based on a model-electrode were nearly identical to the experimental results.
•Numerical simulation method with nonlinear FEM and FVM are proposed.•Nonlinear mechanical characteristics of SE are simulated with nonlinear FEM.•The numerical results are validated with EIS and X-ray CT measurements.•The numerical and experimental results are in good agreement.
In Fig. 5 on p. 311 of our Phys. Lett. B 740 (2015) 303 an adjustment by 180∘ is required for the phases with respect to the L=2,M=1 wave, of the following waves: L=1,3,5 with M=1, and L=2 with M=2. ...After this correction (Fig. 5 (corrected) below), the extracted partial waves describe the angular distribution of the η(′) in the Gottfried-Jackson (GJ) frame, using Eq. (4) with implicit Condon-Shortley phase convention. The other results of our paper are not affected. The right-handed GJ coordinate system was defined by the z-axis pointing in the direction of the beam in the η(′)π− center-of-mass system and the y-axis pointing in the direction of precoilGJ×pbeamGJ.
We report on a measurement of hard exclusive π0 muoproduction on the proton by COMPASS using 160GeV/c polarised μ+ and μ− beams of the CERN SPS impinging on a liquid hydrogen target. From the average ...of the measured μ+ and μ− cross sections, the virtual-photon proton cross section is determined as a function of the squared four-momentum transfer between initial and final proton in the range 0.08(GeV/c)2<|t|<0.64(GeV/c)2. The average kinematics of the measurement are 〈Q2〉=2.0(GeV/c)2, 〈ν〉=12.8GeV, 〈xBj〉=0.093 and 〈−t〉=0.256(GeV/c)2. Fitting the azimuthal dependence reveals a combined contribution by transversely and longitudinally polarised photons of (8.2±0.9stat−1.2+1.2|sys)nb/(GeV/c)2, as well as transverse-transverse and longitudinal-transverse interference contributions of (−6.1±1.3stat−0.7+0.7|sys)nb/(GeV/c)2 and (1.5±0.5stat−0.2+0.3|sys)nb/(GeV/c)2, respectively. Our results provide important input for modelling Generalised Parton Distributions. In the context of the phenomenological Goloskokov-Kroll model, the statistically significant transverse-transverse interference contribution constitutes clear experimental evidence for the chiral-odd GPD E‾T.
A 2.5 m long liquid hydrogen target for COMPASS Bielert, E; Bremer, J; Doshita, N ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
05/2014, Volume:
746
Journal Article
Peer reviewed
Open access
A 2.5 m long liquid hydrogen target has been developed for the COMPASS experiment at CERN to investigate the nucleon spin structure via the Deeply Virtual Compton Scattering (DVCS) process. To ...recognize exclusive DVCS events, produced photons and slow protons need to be detected. In order to do so, the material budget around the target has to be minimal. A 0.125 mm thick Kapton super( registered )Kapton registered target cell and a 1 mm thick carbon fiber vacuum chamber with a Mylar super( registered )Mylar registered window have been constructed and tested. Finally, the target system was successfully employed during the DVCS pilot run in COMPASS at the end of 2012. The objective of this paper is to give a detailed description of this newly developed liquid hydrogen target apparatus.
New results for the double spin asymmetry A1p and the proton longitudinal spin structure function g1p are presented. They were obtained by the COMPASS Collaboration using polarised 200 GeV muons ...scattered off a longitudinally polarised NH3 target. The data were collected in 2011 and complement those recorded in 2007 at 160 GeV, in particular at lower values of x. They improve the statistical precision of g1p(x) by about a factor of two in the region x≲0.02. A next-to-leading order QCD fit to the g1 world data is performed. It leads to a new determination of the quark spin contribution to the nucleon spin, ΔΣ, ranging from 0.26 to 0.36, and to a re-evaluation of the first moment of g1p. The uncertainty of ΔΣ is mostly due to the large uncertainty in the present determinations of the gluon helicity distribution. A new evaluation of the Bjorken sum rule based on the COMPASS results for the non-singlet structure function g1NS(x,Q2) yields as ratio of the axial and vector coupling constants |gA/gV|=1.22±0.05 (stat.)±0.10 (syst.), which validates the sum rule to an accuracy of about 9%.
A 2.5m long liquid hydrogen target for COMPASS Bielert, E.; Bremer, J.; Doshita, N. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
05/2014, Volume:
746
Journal Article
Peer reviewed
Open access
A 2.5m long liquid hydrogen target has been developed for the COMPASS experiment at CERN to investigate the nucleon spin structure via the Deeply Virtual Compton Scattering (DVCS) process. To ...recognize exclusive DVCS events, produced photons and slow protons need to be detected. In order to do so, the material budget around the target has to be minimal. A 0.125mm thick Kapton® target cell and a 1mm thick carbon fiber vacuum chamber with a Mylar® window have been constructed and tested. Finally, the target system was successfully employed during the DVCS pilot run in COMPASS at the end of 2012. The objective of this paper is to give a detailed description of this newly developed liquid hydrogen target apparatus.
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