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We present the development of a dual-detector system designed for investigating the spectral shape of forbidden non-unique beta decays. Two PbMoO 4 scintillating crystals were carefully prepared for heat and light detection at milli-Kelvin (mK) temperatures. Notably, one crystal was synthesized using archaeological lead, while the other was composed of natural modern lead. The significance of employing two crystals lies in their identical dimensions and proximity, resulting in similar environmental background exposure. Their distinct internal radioactivities, particularly associated with 210 Pb, introduce a distinguishing factor between the spectra measured in the two detectors. Our detection method includes achieving clear particle identification through the relative amplitudes of light and heat signals for both crystals. This report compares the electron-induced spectra within energy regions both below and above the endpoint of 210 Bi beta decay. This comparative study provides valuable insights into an exact measurement of the 210 Bi decay spectrum, forbidden non-unique beta decay. [ABSTRACT FROM AUTHOR]

We present advancements in a finite element method for computing the physical properties of magnetic microcalorimeters (MMCs). Utilizing the COMSOL package, we conducted 3D simulations of a meander-shaped Nb coil with a realistic geometry. The resulting magnetic field distribution showed good agreement with a previous 2D simulation and revealed non-negligible differences at the side edge of the sensor material. Employing the simulation results, we calculated the MMC properties and compared them with previous measurements. Our calculated values closely align with the measured values for the sensor magnetization, the pulse heights from alpha detection, and the coil inductance. [ABSTRACT FROM AUTHOR]

We present the development of a heat flow model utilizing a scintillating crystal for heat and light detection. By analyzing the measured light signals from α - and β / γ -induced events in a CaMoO 4 crystal, we describe the time-dependent behavior of the scintillation emission and the subsequent generation of delayed phonons in the crystal. The phonon detection channel model incorporates both prompt and delayed generation of a thermal phonons; these are absorbed in a phonon collector film on the crystal surface or converted into a thermal phonon distribution in the crystal. A reasonable agreement is observed in the comparison between the measured signals and the simulated signals derived from the model study. We attribute the observed pulse shape discrimination to the presence of the delayed phonons associated with the scintillation process. [ABSTRACT FROM AUTHOR]

Redistribution of vibrational energy in the adenine–uracil base pair is studied when the base pair undergoes an intermolecular interaction with an overtone-bending vibration excited H2O(2 ν bend) molecule. Energy transfer is calculated using the structural information obtained from density functional theory in the solution of the equations of motion. Intermolecular vibrational energy transfer (VET) from H2O(2 ν bend) to the uracil–NH stretching mode is efficient and rapidly followed by intramolecular vibrational energy redistribution (IVR) resulting from coupling between vibrational modes. An important pathway is IVR carrying energy to the NH-stretching mode of the adenine moiety in a subpicosecond scale, the energy build-up being sigmoidal, when H2O interacts with the uracil–NH bond. The majority of intermolecular hydrogen bonds between the base pair and H2O are weakened but unbroken during the ultrafast energy redistribution period. Lifetimes of intermolecular HB are on the order of 0.5 ps. The efficiency of IVR in the base pair is due to near-resonance between coupled CC and CN vibrations. The resonance also exists between the frequencies of H2O bend and NH stretch, thus facilitating VET. When H2O interacts with the NH bond at the adenine end of the base pair, energy flow in the reverse direction to the uracil–NH stretch is negligible, the unidirectionality discussed in terms of the effects of uracil CH stretches. The energy distributed in the CH bonds is found to be significant. The IVR process is found to be nearly temperature independent between 200 and 400 K. [ABSTRACT FROM AUTHOR]

Herein, we report the magnetodielectric effect in a single crystal of (CH3NH3)2MnCl4, an organic–inorganic hybrid layered perovskite having a composition of A2MX4 (A = organic anion, M = metal divalent ion, X = halogen cation). Magnetic property measurements reveal that a magnetic phase transition to antiferromagnetism appears at 47 K and a spin-flop transition occurs at 3.5 T in the magnetization (M) curve. We observed a considerable maximum magnetodielectric (MD) effect of 0.4% at 8 K. Furthermore, it was found that the MD effect is proportional to M2 in low magnetic fields and the MD effect starts to saturate at the spin-flop transition field. We proposed a magnetic structure model to explain the mechanism of the peculiar step-like MD effect induced by the spin reorientation. [ABSTRACT FROM AUTHOR]

The interaction between small-scale waves and a larger-scale flow can be described by a multi-scale theory that forms the basis for a new class of parameterizations of subgrid-scale gravity waves (GW) in weather and climate models. The development of this theory is reviewed here. It applies to all interesting regimes of atmospheric stratification, i.e., also to moderately strong stratification as occurring in the middle atmosphere, and thereby extends classic assumption for the derivation of quasi-geostrophic theory. At strong wave amplitudes a fully nonlinear theory arises that is complemented by a quasilinear theory for weak GW amplitude. The latter allows the extension to a spectral description that forms the basis of numerical implementations that avoid instabilities due to caustics, e.g., from GW reflection. Conservation properties are discussed, for energy and potential vorticity, as well as conditions under which a GW impact on the larger-scale flow is possible. The numerical implementation of the theory for GW parameterizations in atmospheric models is described, and the consequences of the approach are discussed, as compared to classic GW parameterizations. Although more costly than the latter, it exhibits significantly enhanced realism, while being considerably more efficient than an approach where all relevant GWs are to be resolved. The reported theory and its implementation might be of interest also for the efficient and conceptually insightful description of other wave-mean interactions, including those where the formation of caustics presents a special challenge. [ABSTRACT FROM AUTHOR]

Cooling performance and energy conservation are important requirements in modern industries and machines. However, low thermal conductivity is the main limitation in developing energy-efficient heat-transfer fluids for cooling purposes. In this study, nanolubricants with alumina nanoparticles dispersed in a base oil for rotary machines were investigated for improved thermal and tribological performances. Initially, to improve the dispersibility of the nanoparticles in the base oil, the nanoparticles were surface functionalized via a (3-aminopropyl)triethoxysilane (APTES) coating, and the corresponding material and thermophysical properties were analyzed. Subsequently, the reliability of the nanolubricant for long-term operation was investigated by applying it to a small platform and performing a rolling contact fatigue (RCF) test that simulates the actual operating environment. The results show that the thermal conductivity improved with an increase in the particle concentration by up to 5.78% at 2 vol.% particle fraction as compared to that of the conventional lubricant (base oil). Furthermore, an RCF test of the nanolubricant performed in a real environment showed that the roller bearing life improved by approximately 3.23 times, owing to a ~ 5.88% reduction in lubricant temperature, modified frictional characteristics from polishing, and nanofin effects of the nanoparticles. [ABSTRACT FROM AUTHOR]

We report a detector model study for light detectors having Ge and Si wafers as absorbers with a metallic magnetic calorimeter (MMC) readout. The model explains the heat flow processes between the thermal components in the detector system, including athermal and thermal phonon transfers and electronic heat diffusion. The temperature dependence of the thermal conductance values was in good agreement with their expectations. The analysis also resulted in finding the characteristic time constants of the athermal phonons for direct absorption in the phonon collector film and for the downconversion to thermal phonons of the absorber wafers. It is a complete detector model to be applied for various detector variations such as the type and dimensions of the wafer absorber. [ABSTRACT FROM AUTHOR]

The East Asian marginal seas (EAMS) are one of the fastest‐warming ocean regions globally. This study presents the long‐term trends (1982–2020) of extreme ocean warming events called "marine heatwaves" over the EAMS and examines the relationships between marine heatwave trends and mean SST warming trends. We focus on five subregions with different influences from atmospheric perturbation and ocean currents: the northern East Sea (N‐ES), southern East Sea, Yellow Sea, Korea Strait (KS), and East China Sea (ECS). During the past four decades, marine heatwave duration and intensity in the EAMS have increased to approximately +4 days and +0.3°C per decade on average, respectively. In summer, the positive trend of marine heatwaves is the highest in the ECS, primarily due to the rapidly increasing mean sea surface temperature (SST). In winter, the N‐ES reveals remarkably rapid increases in marine heatwave properties in the last two decades, with increasing rates of approximately 6.2 (4.9) times longer total duration (stronger intensity) than the global average changes. Beyond the impact of the rapid increase in mean SST, the N‐ES marine heatwaves can be further extended due to the northward shift of the East Korea Warm Current. In general, mean SST changes are critical to the increasing trend in marine heatwave duration and intensity. This study further emphasizes that the changes in ocean circulation may expedite more rapid changes in extreme ocean events, which can produce more vulnerability in some places, such as the N‐ES, to marine heatwaves under continued global warming. Plain Language Summary: Extreme warming events of the ocean occurring from several days to weeks significantly impact marine ecosystems. This study investigates the increasing trends of extremely high ocean warming, namely "marine heatwave," over East Asian marginal seas. During the past four decades, marine heatwave duration and intensity have increased to approximately +4 days and +0.3°C per decade on average, respectively. Comparing the earlier period (1982–2000) and the recent period (2001–2020), the most dramatic changes in marine heatwave properties, including frequency, duration, and intensity, occur in the northern East Sea in winter, significantly increasing 763.33% in duration. During summer, the East China Sea reveals the most significant increasing ratio of marine heatwave properties, with change rates of 227.07% in duration. Marine heatwave characteristics have a statistically increasing trend in both seasons in most regions due to global warming. Beyond the impact of the change in mean SST, we find the change in SST variance via shifting ocean current leads to the excessive trend of marine heatwaves. Key Points: East Asian Marine heatwave duration and intensity have enhanced to approximately +4 days and +0.3°C per decadeDuring winter, the marine heatwave duration over northern East Sea regions experiences a dramatic increase of 763.33%, much higher than the global average increase of 122.63%Northward ocean current variance is a significant factor in the excessive increase of marine heatwave duration, in addition to the changing mean sea surface temperature [ABSTRACT FROM AUTHOR]

This document is a correction notice for an article titled "Thermal Model Improvement in Phonon Detection Channels Using a Scintillating Crystal" published in the Journal of Low Temperature Physics. The correction addresses several errors in the original article, including incorrect terms and subscripts. The corrected version of the article can be found online. The document also includes contact information for the author. [Extracted from the article]

The performance of the novel fish anchor has been assessed through field tests. The tests were carried out at three different locations in the Swan River, Perth. The water depths were 2.91–4.73 m. The riverbed soils consisted of clay (Location 1), silty clay (Location 2) and silt (Location 3). The anchor was installed in the riverbed by dropping first through an air column followed by a water column, and finally striking the riverbed at an impact velocity of 10.4 (Location 1), 11.43 (Location 2), 11.72 (Location 3) m/s. The anchor tip embedment depth in the riverbed was measured at 1–2.5 times the anchor length. For similar impact velocity, the tip embedment depth in clay was 1.56–1.68 and 2–2.1 times of that in silty clay and silt, respectively. The capacity was found to reduce with loading angle at the padeye to the horizontal. The ultimate capacity was 1.5–2.6 times the weight of the anchor submerged in water for loading angle 90°, which increased to 8.2–15.6 times the weight for θ0=∼16°. The fish anchor dove, as opposed to pull out of the riverbed, for loading angles ≤37–47° , resulting in nonelliptical failure envelopes, which have been expressed mathematically. [ABSTRACT FROM AUTHOR]

The ionospheric density displays hemispheric asymmetries in the polar region due to various hemispheric differences, for example, in the offset between geographic and geomagnetic poles and in the geomagnetic field strength. Using ground‐based ionospheric measurements from Vertical Incidence Pulsed Ionospheric Radar with Dynasonde analysis at Jang Bogo Station (JBS), Antarctica and from EISCAT Svalbard Radar (ESR) where both sites are located mostly in the polar cap, we investigate the hemispheric differences in the ionospheric density between the northern and southern hemispheres for geomagnetically quiet and solar minimum condition. The results are also compared with Thermosphere Ionosphere Electrodynamic Global Circulation Model (TIEGCM) simulations. The observations show larger density and stronger diurnal and seasonal variations at JBS in the southern hemisphere than at Svalbard in the northern hemisphere. The diurnal variations of the density peak height are also observed to be much larger at JBS. In both hemispheres, the ionospheric density is significantly reduced in winter due to the limited solar production at high geographic latitudes, but TIEGCM considerably overestimates winter density, which is even larger than summer density, especially in the northern hemisphere. Also existed are the differences in the equinoctial asymmetry between the observations and the simulations: the daytime F‐region density is observed to be larger in fall than in spring in both hemispheres, but TIEGCM shows the opposite. In general, most of the observed asymmetrical density are much weaker in the model simulation, which may result from lack of proper magnetospheric forcings and neutral dynamics in the model. Plain Language Summary: The global ionospheric density is not symmetric around the equator due to various reasons. The main reason for the asymmetry would be the asymmetric characteristics of the geomagnetic field. The ionospheric plasma motions are strongly controlled by the magnetic field lines and the magnetospheric energy inputs dominate the polar ionosphere. Therefore, the asymmetric geometry of the magnetic field lines and the offset between the geomagnetic and geographic poles can produce asymmetric density distributions of the ionosphere. However, the investigation of the hemispheric asymmetry has been mostly restricted to the low and mid‐latitude ionosphere and little study has been conducted in the polar ionosphere, mainly due to the lack of observations in the southern hemisphere. Since the establishment of the Jang Bogo Station (JBS), Antarctica in 2014, Korea Polar Research Institute (KOPRI) has been operating various instruments to observe the ionosphere in association with the thermosphere and the magnetosphere. These observations allow us to investigate the hemispheric asymmetry of the ionospheric density by comparing with the observations in the northern polar region. It is found that the diurnal and seasonal variations of the ionospheric density are much stronger at JBS in the southern hemisphere than in Svalbard in the northern hemisphere. Key Points: The polar ionospheric density shows larger magnitude and stronger diurnal and seasonal variations at Jang Bogo Station than in SvalbardThe daytime density shows an equinoctial asymmetry which is larger in fall equinox than in spring equinoxThermosphere Ionosphere Electrodynamic Global Circulation Model significantly overestimates the winter density at high latitudes and shows the opposite equinoctial asymmetry to the observations [ABSTRACT FROM AUTHOR]

AMoRE is an international project to search for the neutrinoless double beta decay of 100 Mo using a detection technology consisting of magnetic microcalorimeters (MMCs) and molybdenum-based scintillating crystals. Data collection has begun for the current AMORE-I phase of the project, an upgrade from the previous pilot phase. AMoRE-I employs thirteen 48 depl. Ca 100 MoO 4 crystals and five Li 2 100 MoO 4 crystals for a total crystal mass of 6.2 kg. Each detector module contains a scintillating crystal with two MMC channels for heat and light detection. We report the present status of the experiment and the performance of the detector modules. [ABSTRACT FROM AUTHOR]

We developed a simple small-scale experiment to measure the beta decay spectrum of 3 H. The aim of this research is to investigate the presence of sterile neutrinos in the keV region. Tritium nuclei were embedded in a 1 × 1 × 1 cm 3 LiF crystal from the 6 Li(n, α ) 3 H reaction. The energy of the beta electrons absorbed in the LiF crystal was measured with a magnetic microcalorimeter at 40 mK. We report a new method of sample preparation, experiments, and analysis of 3 H beta measurements. The spectrum of a 10-hour measurement agrees well with the expected spectrum of 3 H beta decay. The analysis results indicate that this method can be used to search for keV-scale sterile neutrinos. [ABSTRACT FROM AUTHOR]

Sm–Nd chronometers use 146 Sm and 147 Sm to determine the ages of major events in the early Solar System. Their half-lives are the most important nuclear parameters determining the accuracy of chronometry. However, the 146 Sm half-life is not well-established: the published values differ by ∼ 30%, which results in significant uncertainties in the Solar System timeline. We are re-measuring the half-lives of 146 Sm and 147 Sm using decay energy spectroscopy and metallic magnetic calorimeters to improve the accuracy of the Sm–Nd chronometers. We report recent experimental results from our first measurement of a 147 Sm source, as well as status and plans for experiments on 146 Sm. [ABSTRACT FROM AUTHOR]

We developed a two-stage temperature control system for a long-term stable measurement of AMoRE neutrinoless double beta decay experiment using a dilution refrigerator. The first-stage control was made with a standard PID system using an AC bridge with a ruthenium oxide thermometer as the main thermometer of the mixing chamber plate. The second-stage control was obtained with a magnetic microcalorimeter (MMC) that is configured as a sensitive thermometer for a detector tower, the main experiment. Under single-stage temperature control on the temperature of the mixing chamber plate only with the RuO2 thermometer, the MMC recorded temperature stability of the detector plate of 9 μK rms over 100 min. Under two-stage temperature control, with the first-stage of the mixing chamber plate at 11 mK via the RuO2 thermometer and the second-stage of the detector plate at 12 mK via the MMC, the MMC recorded a temperature stability of 0.5 μK rms over 100 min. Moreover, the heat channels of the AMoRE experiment obtained considerable improvement in energy resolutions when switching from single-stage (RuO2) to two-stage (RuO2 + MMC) control. [ABSTRACT FROM AUTHOR]

The AMoRE collaboration is preparing for the AMoRE-II experiment that will probe neutrinoless double beta decay with 100 kg of 100Mo isotope. The 100Mo nuclide will be mainly in the form of lithium molybdate crystals that are instrumented with metallic magnetic calorimeters (MMC), which detect the phonon excitations produced by electrons from neutrinoless double beta decay in the crystals. The energy resolution at a Q-value = 3.034 MeV is around 10 keV within a temperature ranging between 10 and 20 mK. Increasing the crystal mass of individual detector modules will reduce the number of detector channels and allow a few practical advantages associated with crystal growing, detector preparation, and operation of the experiment. To this end, we carried out an experiment with a 6 cm (diameter (D)) × 6 cm (height (H)) cylindrical lithium molybdate crystal of 516 g mass, which is 73% more massive than the 5 cm (D) × 5 cm (H) crystals that are currently being used in the AMoRE-I setup. We found that the larger crystal detector shows good performance characteristics in terms of energy resolution, signal time constant and particle identification capability, which makes it a suitable option for the AMoRE-II experiment. [ABSTRACT FROM AUTHOR]

The advanced Mo-based rare process experiment (AMoRE) is an international project searching for the neutrinoless double beta ( 0 ν β β ) decay of 100 Mo using low-temperature calorimetric detection of heat and light signals based on magnetic microcalorimeter (MMC) readouts. Li 2 MoO 4 crystals have been considered as the main target crystals for the second phase of the AMoRE project, which aims to use 100 kg of 100 Mo. However, the hygroscopicity of Li 2 MoO 4 requires moistureless processes during surface treatment, storage, detector assembly, and installation. PbMoO 4 crystals are nonhygroscopic and exhibit high scintillation efficiency, often leading to high particle discrimination power in the phonon channel via pulse-shape analysis and light/heat ratio variation. A low-temperature detector setup with a 1 cm 3 cubic crystal of PbMoO 4 was prepared for simultaneous heat and light detection based on MMC readouts. After study of internal background control using archeological Pb, PbMoO 4 crystal can be a promising candidate crystal. We present a feasibility study of PbMoO 4 crystals for a 0 ν β β experiment. [ABSTRACT FROM AUTHOR]

This paper reports the development of a particle breakage model within a finite-element (FE) framework based on the modified Mohr–Coulomb model (MMC). A modified form of the strength-dilatancy relationship is used to incorporate additional energy consumed due to particle breakage. A new particle breakage index is introduced and constitutively linked to the mobilized friction angle. The model is verified against carefully conducted drained triaxial tests on medium-dense calcareous sand obtained from offshore Australia as well as other published data. The model is implemented in the FE program ABAQUS for both small strain and large deformation FE analyses in practical field problems. Several important microscopic observations can be made from the proposed model that are not limited to identifying soil regions where particle breakage is maximized. Due to its inherent simplicity, the newly developed model can provide reasonable predictions for soil-structure interaction problems in calcareous sands. [ABSTRACT FROM AUTHOR]

This paper provides insight into the behavior of a stiffened caisson anchor under inclined cyclic loading in calcareous silt. A series of tests was conducted in a beam centrifuge. A monotonic test was first performed, quantifying the pure monotonic capacity, and then four cyclic loading tests varying the mean load, amplitude, and number of cycles. Cyclic soil characterization T-bar tests and caisson tests were linked. Undrained cyclic T-bar tests led to generate excess pore pressure, resulting in degradation of soil strength and stiffness. For partially drained cyclic caisson tests, the excess pore pressure generated during initial undrained monotonic loading experienced partial dissipation. Healing due to consolidation outweighed the damage due to initial pore pressure generation. Postcyclic monotonic capacity was found to be up to 35% higher compared with the pure monotonic capacity unless the anchor failed during cyclic loading. Measured rotation indicated the evolution of anchor failure mechanism. Caisson capacity under inclined loading was presented as a failure envelope, with the effect of cyclic loading accentuated. The contribution of the soil–chain interaction on the caisson capacity was minimal. No trenching was apparent on the soil surface, and no gap was formed around the anchor in the considered centrifuge testing conditions. [ABSTRACT FROM AUTHOR]

We found the signatures of the multiple prompt penetration electric fields and the disturbance dynamo electric field having impacts on the East Asian sector ionosphere along the meridional chain thoroughly from the equator, low‐mid to high latitudes during the space weather event of 3–5 November 2021. The observation is made on global positioning system‐total electron content (GPS‐TEC), digisonde, and magnetometer stations. In the main phase of the storm, intense modulations of vertical total electron content (VTEC) and critical frequency (foF2) are observed as coherently fluctuating with interplanetary electric field (IEF) and IMF Bz reorientations. It is diagnosed that the oscillations in the disturbance polar current 2 (DP2) current system directly penetrate meridianally from high to equatorial latitudes, leading to the significant changes in ionospheric electrodynamics that governs the density fluctuations. The wavelet spectra of VTEC, foF2, h'F (virtual height), H‐components and IEF give a result of common and dominant periodicity occurring at ∼1 hr. This result suggests that the wavelike oscillations of VTEC and foF2 and H component are associated with prompt penetration electric fields. Plain Language Summary: Geomagnetic storm time electrodynamics of the ionosphere is severely affected by magnetospheric convection electric field induced by solar wind‐induced magnetospheric dynamo, and ionospheric disturbance dynamo (DD) generated by global thermospheric wind circulation and joule heating at high latitude. The Magnetospheric convection electric field can penetrate instantly into the equatorial ionosphere known as prompt penetration (PP) electric field, while, the thermospheric wind and its associated disturbances can reach the equator with a time delay. During the main phase of the storm, observations showed intense modulations in vertical total electron content (VTEC), critical frequency from equator to high latitudes associated with PP electric fields. In recovery phase, disturbances in VTEC, foF2, and virtual height (h'F) are caused by either DD electric field or traveling ionospheric disturbances. Further analysis in this study suggests the evidence of causal relationship among the interplanetary electric field, disturbance polar current 2 current system, and ionospheric density oscillations. Wavelets analysis shows a common and dominant periodicity of ∼1 hr in interplanetary and ionospheric parameters. Key Points: Prompt penetration electric fields signature observed along the ionosphere meridian in East‐AsiaInfiltration of disturbance polar current 2 current to the equator to cause the ionospheric density fluctuationsThe oscillations of the observed parameters (total electron content, frequency of F2, and H‐component) along the meridional chain coincide with that of interplanetary electric field at a ∼1 hr periodicity [ABSTRACT FROM AUTHOR]

Quasi‐biennial oscillations (QBOs) in thirteen atmospheric general circulation models forced with both observed and annually repeating sea surface temperatures (SSTs) are evaluated. In most models the QBO period is close to, but shorter than, the observed period of 28 months. Amplitudes are within ±20% of the observed QBO amplitude at 10 hPa, but typically about half of that observed at lower altitudes (50 and 70 hPa). For almost all models, the oscillation's amplitude profile shows an overall upward shift compared to reanalysis and its meridional extent is too narrow. Asymmetry in the duration of eastward and westward phases is reasonably well captured, though not all models replicate the observed slowing of the descending westward shear. Westward phases are generally too weak, and most models have an eastward time mean wind bias throughout the depth of the QBO. The intercycle period variability is realistic and in some models is enhanced in the experiment with observed SSTs compared to the experiment with repeated annual cycle SSTs. Mean periods are also sensitive to this difference between SSTs, but only when parametrized non‐orographic gravity wave (NOGW) sources are coupled to tropospheric parameters and not prescribed with a fixed value. Overall, however, modelled QBOs are very similar whether or not the prescribed SSTs vary interannually. A portrait of the overall ensemble performance is provided by a normalized grading of QBO metrics. To simulate a QBO, all but one model used parametrized NOGWs, which provided the majority of the total wave forcing at altitudes above 70 hPa in most models. Hence the representation of NOGWs either explicitly or through parametrization is still a major uncertainty underlying QBO simulation in these present‐day experiments. [ABSTRACT FROM AUTHOR]

The Quasi‐Biennial Oscillation initiative (QBOi) is a model intercomparison programme that specifically targets simulation of the QBO in current global climate models. Eleven of the models or model versions that participated in a QBOi intercomparison study have upper boundaries in or above the mesosphere and therefore simulate the region where the stratopause semiannual oscillation (SAO) is the dominant mode of variability of zonal winds in the tropical upper stratosphere. Comparisons of the SAO simulations in these models are presented here. These show that the model simulations of the amplitudes and phases of the SAO in zonal‐mean zonal wind near the stratopause agree well with the information derived from available observations. However, most of the models simulate time‐average zonal winds that are more westward than determined from observations, in some cases by several tens of m·s–1. Validation of wave activity in the models is hampered by the limited observations of tropical waves in the upper stratosphere but suggests a deficit of eastward forcing either by large‐scale waves, such as Kelvin waves, or by gravity waves. [ABSTRACT FROM AUTHOR]

The existence of a deep countercurrent in the subtropical northwest Pacific, named Subtropical Deep Countercurrent (STDCC), has been revealed by moored current‐meter data obtained from a buoy system (∼21.6°N, ∼132.8°E) during 4 years (2010–2014). The climatological average of Argo‐based absolute geostrophic velocities and ocean reanalyzes have further confirmed the spatial picture of the eastward‐flowing STDCC. STDCC is identified as a time‐mean feature in the latitudinal range of 19°–25°N with a meridional scale of 200–300 km that persistently appears from 125° to 180°E and slightly shifts to the north as it goes east. Vertically, STDCC is mostly found below 1,000 m with its core located between the depths of 1,250 and 2,000 m, which corresponds to the undercurrent's meridional pattern with increasing depth northward and a meridional space of 2°–4°. Nevertheless, STDCC is distinctive where it lies along ∼27.6 − σθ, which is deeper than the North Equatorial Undercurrent's density layer (∼27.0 − σθ). The mean velocity of STDCC at 2,000 m observed by mooring measurements was approximately 0.2 ± 0.15 cm s−1 with a maximum speed of approximately 5.59 cm s−1. The ocean reanalyzes also support the existence of STDCC with mean velocity of approximately 0.2–0.6 cm s−1 west of 145°E and can be as large as 1.6 cm s−1 at the eastern region. The results show that STDCC is closely related to the westward‐propagating eddies. Our finding emphasizes that the convergence of the cyclonic and anticyclonic eddies possibly generates time‐mean zonally elongated eastward flows forming STDCC feature. Plain Language Summary: Information about the deep circulation in the subtropical northwest Pacific is very limited owing to a lack of observational evidence. By using direct current measurements for 4 years (2010–2014), this study provides a description of the first observation of the newly identified deep eastward flows, named Subtropical Deep Countercurrent (STDCC). Argo‐based absolute geostrophic currents and ocean reanalyzes have further confirmed the existence of this current, which found around 19°–25°N at 125°–180°E longitude and core's depths of between 1,250 and 2,000 m. The maximum mean velocity of STDCC at 2,000 m observed by mooring measurements was approximately 0.2 ± 0.15 cm s−1 with a maximum speed of approximately 5.59 cm s−1, which is relatively weaker than the tropical North Equatorial Undercurrent (NEUC) and the upper‐layer Subtropical Countercurrent. In comparison, the model results show that STDCC has typical velocity of approximately 0.2–0.6 cm s−1 west of 145°E and greater velocity at the eastern region reaches 1.6 cm s−1. The westward‐propagating eddies have been suggested as being the possible dynamics behind the STDCC's generation. Key Points: A newly identified deep countercurrent has been found in the subtropical northwest Pacific from observations and ocean reanalyzesSubtropical Deep Countercurrent (STDCC) is identified in the range of 19°N–25°N, and 125°E to 180°E with its core depths between 1,250 and 2,000 mThe generation of STDCC is strongly associated with the westward‐propagating eddies [ABSTRACT FROM AUTHOR]

Gravity wave (GW) activities in the upper mesosphere (80–100 km) and their potential sources are investigated using meteor radar observations at King Sejong Station, Antarctica (KSS; 62.22°S, 58.78°W) during recent 14 years (2007–2020). GW activities are estimated by horizontal wind variances of small‐scale GWs (periods <2 h, horizontal wavelength <400 km, or vertical wavelength <3–5 km). The wind variances show clear semiannual variations with maxima at solstices, and annual variations are also seen above z = 90 km. The deseasonalized wind variances at z = 96.8 km have a statistically significant periodicity of ∼11 years that can be associated with solar cycle variations. Three major potential GW sources in the lower atmosphere are examined. Orography is a potential source of GWs in winter and autumn, when the basic‐state wind is westerly from the surface up to the mesosphere. The residual of the nonlinear balance equation (RNBE) at 5 hPa, a diagnostic of the GWs associated with jet stream, is the largest in winter and has a secondary maximum in spring. The correlation between the observed GWs and RNBE is significant in equinoxes, while correlation is low in winter. Deep convection in storm tracks is a potential source in autumn and winter. Secondary GWs generated in the mesosphere can also be observed in the upper mesosphere. Ray‐tracing analysis for airglow images observed at KSS indicates that secondary GWs are mostly generated in winter mesosphere, which may be associated with the breaking of orographic GWs. Key Points: Gravity wave(GW) activities in the upper mesosphere over the Antarctic Peninsula are investigated using 14‐year meteor radar dataOrography and jet are the primary wave sources in winter and equinoxes, respectively, and convection is a possible source in autumn/winterRay‐tracing of GWs observed from airglow measurements suggests that secondary GWs are mainly generated in winter mesosphere [ABSTRACT FROM AUTHOR]

Its pathogenesis remains unclear; however, several reports suggest that it might be triggered by vaccination.3,4 Herein, we report the first case of Wells' syndrome, a new post-vaccination adverse event, after Oxford-AstraZeneca COVID-19 vaccination. Wells' syndrome following Oxford-AstraZeneca COVID-19 vaccination In conclusion, the development of Wells' syndrome and Oxford-AstraZeneca COVID-19 vaccination may be related, with delayed-type hypersensitivity reaction as a possible mechanism. [Extracted from the article]

Background and purpose: Various clinical and neuroimaging predictive factors have been identified for the recovery of upper extremity (UE) motor function after stroke. However, few studies have addressed factors related to the recovery of lower extremity (LE) motor function after stroke or performed direct comparisons of UE and LE motor recovery in the same set of patients. In this study, predictive factors for UE and LE motor recovery after stroke were investigated using clinical and neuroimaging characteristics. Methods: Forty‐two subacute ischaemic stroke patients underwent structural and functional magnetic resonance imaging data acquisition and cognitive/behavioral assessments using the Fugl–Meyer assessment, the National Institutes of Health Stroke Scale (NIHSS) and the Mini‐Mental State Examination (MMSE) 2 weeks after stroke onset. Neuroimaging factors, including corticospinal tract (CST) fractional anisotropy, lesion volume, CST lesion load and interhemispheric homotopic functional connectivity, were extracted. The outcome of motor function was assessed by Fugl–Meyer assessment scores 3 months after onset. Results: Early clinical and neuroimaging factors for predicting motor recovery were noticeably different for UE and LE. UE motor function recovery was related to age, NIHSS, MMSE, CST lesion load, lesion volume, ipsilesional CST integrity and interhemispheric homotopic functional connectivity. In contrast, LE motor recovery was related to ipsilesional and contralesional CST integrity and MMSE. Specifically, LE recovery showed a strong relationship to the preservation of cognitive function compared with motor impairment. Conclusions: Our results indicate that different mechanisms underlie UE and LE motor recovery after stroke. LE motor recovery seems to be more intensively modulated by cognitive functions than UE. [ABSTRACT FROM AUTHOR]

We report on the Balloon-borne Investigation of Temperature and Speed of Electrons in the corona (BITSE) mission launched recently to observe the solar corona from ≈ 3 Rs to 15 Rs at four wavelengths (393.5, 405.0, 398.7, and 423.4 nm). The BITSE instrument is an externally occulted single stage coronagraph developed at NASA’s Goddard Space Flight Center in collaboration with the Korea Astronomy and Space Science Institute (KASI). BITSE used a polarization camera that provided polarization and total brightness images of size 1024 × 1024 pixels. The Wallops Arc Second Pointer (WASP) system developed at NASA’s Wallops Flight Facility (WFF) was used for Sun pointing. The coronagraph and WASP were mounted on a gondola provided by WFF and launched from the Fort Sumner, New Mexico station of Columbia Scientific Balloon Facility (CSBF) on September 18, 2019. BITSE obtained 17,060 coronal images at a float altitude of ≈ 128,000 feet (≈ 39 km) over a period of ≈ 4 hrs. BITSE flight software was based on NASA’s core Flight System, which was designed to help develop flight quality software. We used EVTM (Ethernet Via Telemetry) to download science data during operations; all images were stored on board using flash storage. At the end of the mission, all data were recovered and analyzed. Preliminary analysis shows that BITSE imaged the solar minimum corona with the equatorial streamers on the east and west limbs. The narrow streamers observed by BITSE are in good agreement with the geometric properties obtained by the Solar and Heliospheric Observatory (SOHO) coronagraphs in the overlapping physical domain. In spite of the small signal-to-noise ratio (≈ 14 ) we were able to obtain the temperature and flow speed of the western steamer. In the heliocentric distance range 4 – 7 Rs on the western streamer, we obtained a temperature of ≈ 1.0 ± 0.3 MK and a flow speed of ≈ 260 km s−1 with a large uncertainty interval. [ABSTRACT FROM AUTHOR]

Signal amplitudes of low-temperature detectors, vastly used in rare-event searches such as neutrinoless double beta decay experiments, are sensitive to measurement conditions causing instability such as operation temperature fluctuations. Those detector signal amplitudes thus present drifts and shifts over time due to those temperature fluctuations and need to be corrected. This effect degrades the energy resolution and particle discrimination capabilities of the calorimetric detection at low temperatures, with both strongly affecting the sensitivity of rare-event search experiments. Joule heaters were developed and used on absorber crystals in the Advanced Mo-based Rare process Experiment project, to inject periodically a controlled amount of heat, and thus produce reference signals that can be used to correct and thus stabilize the signal amplitudes of the detectors. The pulse height of the heater signals could not be used as a correction parameter as it was affected by various sources of instability. Instead, the rise time of the heater signals was used to generate a correction function describing well the time dependence of the particle-induced events in the crystals and thus provided a significant improvement of the energy resolution and particle discrimination capabilities to separate β / γ and α events. [ABSTRACT FROM AUTHOR]

The interaction between a spudcan and an existing footprint is one of the major concerns during the reinstallation of jack-up rigs. This paper reports the results from a series of centrifuge model tests undertaken to assess the efficiency of a recently developed novel spudcan shape with a flat base and four holes through the base to ease spudcan–footprint interactions. The experimental program was carried out at 200 g in a beam centrifuge. The footprints were created either manually using a cutting tool or through spudcan penetration and extraction allowing a typical operation period as well as an elapsed time prior to reinstallation. While the former allowed a consistent evaluation of the benefits of spudcan shape, removing the additional variability due to soil strength heterogeneity, the latter allowed for examining the effect of real field footprints. For manually created shallow footprints in soft clay, comparing the responses with those on a generic spudcan, it was possible to show that the novel spudcan reduced the maximum horizontal force and moment by up to 47%–62% and 28%–36%, respectively. The critical offset distance was found at 0.75D. For manually created deep footprints in stiff clay, the reductions were 20%–59% and 9%–45%, respectively. The critical offset distance was found at 0.5D. For footprints created by penetrating and extracting a spudcan, the critical offset distance was identified at 0.75D. The efficiency of the novel spudcan was calculated with the reduction of maximum horizontal force and moment by 42%–59% and 21%–62%, respectively. [ABSTRACT FROM AUTHOR]

January 2020 was the first time that most of the world heard about the new Coronavirus disease (COVID-19) but its consequences were still unknown. The future When the pandemic ends, researchers across different countries need to compare differences between pre-pandemic and post-pandemic PA and WB and their determinants. Health and quality of life systems that are well-financed can employ the appropriate number of health professionals, including sport and exercise psychologists, to provide high quality services to everyone during and after the coronavirus pandemic, promoting people's health, PA and WB. The COVID-19 pandemic might be also an opportunity to highlight the interplay of the coronavirus pandemic with the two silent pandemics of PI and MI. [Extracted from the article]

We developed measurement systems for the simultaneous detection of phonon and scintillation signals from Li 2 MoO 4 crystals based on the metallic magnetic calorimeter (MMC) technology. Two measurements were carried out using Li 2 MoO 4 crystals of different sizes. The first measurement was conducted with a compact detection system designed for a 1 × 1 × 1 cm 3 crystal. An advanced light detector with Neganov–Luke phonon amplification was adopted in the compact setup. Later, the second experiment was carried out using a cylindrical Li 2 MoO 4 crystal of 5 cm in diameter and 5 cm in height. Another light detector was implemented with a 2-in. Ge wafer and an MMC sensor. Both measurements resulted in simultaneous detection of heat and light signals. Clear particle discriminations between α - and β / γ -induced events were demonstrated by comparing amplitudes of the heat and light signals in both measurements. The heat signals in the larger setup showed an energy resolution of 18 keV FWHM for 2615 keV γ -rays. The energy linearity of the detector response was investigated for a suitable calibration near 3.034 MeV, the Q value of 100 Mo double-beta decay. [ABSTRACT FROM AUTHOR]

We report progress on the development of a light detector with Neganov–Luke (NL) phonon amplification. Double comb-like electrodes were fabricated on an intrinsic Si wafer to apply an electric field. A metallic magnetic calorimeter was used for a sensitive measurement of the temperature increase originating from the light absorption in the wafer and NL phonon amplification. The NL light detector was applied to the simultaneous detection of heat and light signals from a ZnWO 4 scintillating crystal. Clear amplification of the light signals was obtained for various voltages applied to the electrodes, while no change in the heat signals was observed. The voltage dependence of the measured gain was investigated for a few efficiency parameters, such as the saturation voltage required to suppress the recombination of electron-hole pairs and the heat generation efficiency of the NL effect. [ABSTRACT FROM AUTHOR]

During the St. Patrick's Day storm on 17 March 2015, an all‐sky imager at King Sejong Station (KSS; geo: 62.2°S, 58.8°W; mag: 50.2°S) captured diffuse aurora and a stable auroral red (SAR) arc. Ground‐based Global Positioning System observations were also simultaneously conducted at KSS, but there was no significant increase in the total electron content's rate‐of‐change index or the ionospheric scintillation indices around the SAR arc region. Auroral activities including a SAR arc were also detected by the all‐sky imager at Millstone Hill Station (geo: 42.6°N, 71.4°W; mag: 52.5°N), which is magnetically conjugate to KSS. The total electron content's rate‐of‐change index map around Millstone Hill Station, too, indicates that the ionospheric irregularities occurred only near the diffuse aurora and not in the SAR arc. The northern SAR arc is broader than the southern one and also shows a multiplicity pattern, which may be due to latitude structure within the seasonally dependent midlatitude ionospheric trough. These conjugate observations, despite their hemispheric differences, validate the classical SAR arc mechanism of emission driven by heat conduction from the inner magnetosphere that does not generate small‐scale ionospheric irregularities that can affect Global Positioning System radio signals. Previous studies of SAR arcs and very high frequency radiowave scintillations did show a positive correlation. Key Points: A SAR arc and diffuse aurora were simultaneously observed by all‐sky imagers at two conjugate stations during the St. Patrick's Day storm in 2015Unlike diffuse aurora, SAR arc regions showed no significant increase of ionospheric scintillation indices or the rate of change of the TEC index (ROTI)Our observations at geomagnetic conjugate points suggest that SAR arcs cause no ionospheric irregularities affecting GPS signals, in contrast to effects at VHF [ABSTRACT FROM AUTHOR]

The FeSe nematic phase has been the focus of recent research on iron-based superconductors (IBSs) due to its unusual properties, which are distinct from those of the pnictides. A series of theoretical/experimental studies were performed to determine the origin of the nematic phase. However, they yielded conflicting results and caused additional controversies. Here, we report the results of angle-resolved photoemission and X-ray absorption spectroscopy studies on FeSe detwinned by a piezo stack. We fully resolved band dispersions with orbital characters near the Brillouin zone (BZ) corner, and revealed an absence of any Fermi pocket at the Y point in the 1-Fe BZ. In addition, the occupation imbalance between d x z and d y z orbitals was the opposite of that of iron pnictides, consistent with the identified band characters. These results resolve issues associated with the FeSe nematic phase and shed light on the origin of the nematic phase in IBSs. Twinning is a phenomenon which describes the intergrowth between two identical crystals, and can complicate the analysis of their intrinsic properties both from a physical and structural perspective. Here, the authors use a piezo stack to detwin FeSe crystals and then investigate the band dispersions using photoelectron and X-ray absorption spectroscopies in order to further clarify the origins of the nematic phase in FeSe. [ABSTRACT FROM AUTHOR]

We demonstrate the possibility to extract nuclear state femtosecond lifetimes from two-step γ ray cascades measured with a Ge-detector array. The technique is based on measuring the Doppler shift of a γ ray, caused by the recoil of a preceding γ ray emission. Since the two γ rays are populating/de-populating the same state they form a start/stop signal, the delay of which is compared to the slowing down motion of the nucleus within the target material. A multi-detector array combined with digital acquisition electronics in list mode, allows to measure several angular combinations and two-step cascades efficiently and simultaneously within one single experiment. The concept was demonstrated with the FIPPS array for the 35 Cl(n, γ) 36 Cl reaction, where we obtained good agreement with literature values showing the validity of the method. [ABSTRACT FROM AUTHOR]

Objective: The aim of this study was to determine how gait speed and frontal lobe functionsin community-dwelling older adults in Korea. Design: This was a cross-sectional study. Setting: The study used data from the Korean Frailty and Aging Cohort Survey (KFACS), a multi-center longitudinal study addressing 10 centers across urban, rural, and suburban communities in Korea, between 2016 and 2017. Participants: A total of 1552 older adults who underwent both gait speed tests and cognitive functions tests during the investigation of the KFACS. Measurements: Gait speed was assessed by asking participants to walk from a starting point to a point 4 meters away at a normal gait. Cognitive functions were evaluated using various standardized cognitive functions tests. Results: Gait speed was slower when participants were older or less educated The percentage of women, higher BMI, people with lower incomes, singles, smokers, and drinkers was high in the slower gait group. Also, all cognitive function scores were low and depression score was high in the group with slower walking speed. The slower walking speed showed low physical activity score and high prevalence of hypertension, osteoarthritis and osteoporosis. Among the seven cognitive functions (MMSE, memory, TMT, Recall, Recognition, digit span, and Fab), only TMT showed no significant difference between different gait speed groups. The other six cognitive functions showed higher results in the fastest gait speed group (T3), Participants in middle gait speed group (T2) also showed higher results in five of the seven cognitive function scores as well (Memory, Recall, Recognition, digit span, and Fab). Conclusion: In this study, we found correlation between the slower gait speeds and the decrease in cognitive function, and especially the frontal lobe dysfunction was most prominent of all cognitive dysfunctions. [ABSTRACT FROM AUTHOR]

Inertial fusion implosions are diagnosed using γ rays to characterize the implosion physics or measure basic nuclear properties, including cross sections. For the latter, previously reported measurements at laser facilities using gas Cherenkov detectors are limited by a large systematic uncertainty in the detector response. We present a novel in situ calibration technique using neutron inelastic scattering, which we apply to the new GCD-3 detector. The calibration accuracy is improved by ∼3× over the previous method. [ABSTRACT FROM AUTHOR]

Micropatterned ordered arrays of cobalt (Co) anti-dots on a uniform thin nickel (Ni) underlayer, known as bilayered magnetic anti-dot lattices (BMALs), were fabricated using photolithography and a controlled wet-etching process. The magnetization reversals in a rhomboid BMAL under the application of a field along 0° (i.e., easy axis) and 90° (i.e., hard axis) were investigated using field-dependent magnetic-force microscopy, and the angular dependence of squareness (Mr/Ms) and coercivity (Hc) were studied using magneto-optical Kerr effects. Although the magnetic reversals were dominated by domain-wall motions or domain rotations, reflecting the easy and hard axis characteristics, various other complex reversal processes were also found that depends on the history of the field application. The angular dependence of Mr/Ms and Hc in a BMAL system was completely different from that in a single-layer, Co magnetic anti-dot lattice. Interestingly, a unidirectional and uniaxial component representing the overall magnetic anisotropy was revealed in the BMAL system. The details of these complicated magnetization behaviors were investigated and elaborated. [ABSTRACT FROM AUTHOR]

The microstructural properties of a GaN layer grown on a patterned sapphire substrate (PSS) were studied in detail using transmission electron microscope techniques to determine dislocation and growth behaviors. Regular and uniform recrystallized GaN islands were observed on the protruding pattern. On a flat sapphire surface, the crystallographic orientation relationship of [formula] and [formula] existed between the GaN and the substrate. On the other hand, the orientation relationship of [formula] and [formula] was confirmed among the GaN layer, the recrystallized GaN islands on an inclined sapphire surface and the PSS. The flat surface among the protruding patterns began to fill rapidly with GaN. Then, the GaN gradually overgrew the protruding pattern and coalesced near the summit as the growth time increased. The generation of threading dislocations was observed in the vicinity of the coalescence points near the top of the protruding patterns. [ABSTRACT FROM AUTHOR]

The vibrational relaxation of OH(A 2Σ+;v=1) embedded in solid Ar has been studied over 4–80 K. The interaction model is based on OH undergoing local motions in a cage formed by a face-centered cubic stacking where the first shell atoms surround the guest and connect it to the heat bath through 12 ten-atom chains. The motions confined to the cage are the local translation and libration-rotation of OH and internal vibrations in OH...Ar, their energies being close to or a few times the energies of nearby first shell and chain atoms. The cage dynamics are studied by solving the equations of motion for the interaction between OH and first shell atoms, while energy propagation to the bulk phase through lattice chains is treated in the Langevin dynamics. Calculated energy transfer data are used in semiclassical procedure to obtain rate constants. In the early stage of interaction, OH transfers its energy to libration-rotation intramolecularily and then to the vibrations of the first shell and chain atoms on the time scale of several picoseconds. Libration-to-rotational transitions dispense the vibrational energy in small packages comparable to the lattice frequencies for ready flow. Energy propagation from the chains to the heat bath takes place on a long time scale of 10 ns or longer. Over the solid argon temperature range, the rate constant is on the order of 106 s-1 and varies weakly with temperature. [ABSTRACT FROM AUTHOR]