The effects of microstructural characteristics on the mechanical properties of an aluminum alloy (ADC12: Al–Si11.3–Cu1.9–Zn0.8–Fe0.8–Mg0.2–Mn0.2) produced by various casting technologies are studied ...experimentally and numerically. Six different casting processes are employed: gravity casting, cold-chamber die-casting, hot-chamber die-casting, squeeze casting, twin-rolled continuous casting and heated-mold continuous casting. Microstructural characteristics, dislocation density and defect density vary depending on the casting method, owing to differences in solidification rate, casting pressure and injection speed. The material characteristics of the samples affect their mechanical properties. Multiple regression analysis is carried out to find equations to predict tensile strength using five independent factors: secondary dendrite arm spacing, microporosity rate, diameter of eutectic structures, aspect ratio of eutectic structures and dislocation density. All these factors influence the tensile properties, although to different degrees. The estimated values of tensile strength are in good agreement with experimental results.
Several global databases of eruption properties have been developed in recent years, which contain eruption age, eruption magnitude, eruption style, and volcanic explosivity index. However, their ...examinations of the relationships between eruption and magmatic properties remain qualitative. To explore such relationships, we sampled and petrologically analyzed the eruptive products and have constructed a database of magmatic properties of erupted magmas at Japanese arc volcanoes during the last one hundred thousand years. The 43 erupted magmas were characterized not only by bulk SiO2 content, but also by preeruptive melt SiO2 (inferred from groundmass SiO2 content) and phenocryst contents, which are the second most straightforward proxies of physical and thermodynamic properties of preeruptive magmas. Sample data were collected through a unified procedure using chemical and image analyses and mass balance calculations to obtain groundmass compositions and phenocryst contents. We examined the relationships between magmatic properties and eruption magnitude, M, as the most representative eruption property. Our database includes explosive eruptions of M 3 to 8. By incorporating available literature data for 17 eruptions, we examined 60 eruptions in total. This study distinguished magmas from the bulk composition (e.g., basaltic, andesitic, dacitic and rhyolitic magmas) or melt composition (e.g., basaltic, andesitic, dacitic and rhyolitic melt-bearing magmas). Our results show that the maximum eruption magnitude gradually increases with increasing bulk SiO2 content. The maximum eruption magnitude shows a sharp increase around the compositional boundary between dacitic and rhyolitic melt-bearing magmas. For the eruptions of rhyolitic melt-bearing magmas, the maximum eruption magnitude decreases with increasing phenocryst content. The largest magnitude eruptions (M 8) were of rhyolitic melt-bearing, phenocryst-poor magmas. We compared our data for Japanese arc volcanoes with data for global volcanoes. Despite their different tectonic settings, most eruptions globally are consistent with the pattern observed for eruptions at Japanese arc volcanoes. Notable deviations are supereruptions (M > 7) of monotonous intermediate magmas that occurred more than a million years ago. Although more examination is needed, especially for smaller and effusive eruptions, the observed relationships suggest that melt SiO2 and phenocryst contents are related to maximum eruption magnitude, and should be fundamental components to characterize volcanoes and eruptions in future databases studies.
•Database of properties of erupted magmas in Japan during the last 100 ky•Characterization of magmas by preeruptive melt SiO2 and phenocryst contents•Relationships between magmatic properties and eruption magnitude•Maximum eruption magnitude increases sharply for rhyolitic melt-bearing magmas.•Maximum eruption magnitude decreases gradually with increasing phenocryst content.
We aimed to verify the effectiveness of real-time reverse transcription (rRT) polymerase chain reaction (PCR) for detecting cases of modified measles (M-Me) and for predicting super-spreader ...candidates through the experience of a measles outbreak dominated by M-Me in Yamagata, Japan, during March–April 2017. We applied rRT-PCR to specimens from 35 cases of M-Me, nine cases of typical measles (T-Me) and nine cases of prodromal stage of T-Me (P-Me). From rRT-PCR among the M-Me cases, peripheral blood mononuclear cells (PBMC) showed the highest positive rate (80.0%), followed by throat swab (48.6%), urine (33.3%) and serum (3.1%). The negative result of PBMC in M-Me cases was recovered by the result of a throat swab. In specimens of PBMC, throat swab and urine, M-Me group showed the significantly higher cycle of threshold (i.e., lower viral load) in the rRT-PCR than T-Me and P-Me groups, respectively. Furthermore, three super-spreaders in T-Me or P-Me showed an extremely low cycle of threshold in their throat swab specimens. rRT-PCR using PBMC and throat swab might be helpful for clinical management and measles control by certain detection of M-Me cases and by predicting super-spreading events resulting from measles cases with the high viral load.
With the emergence of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), which causes coronavirus disease 2019 (COVID-19), a high-speed and convenient detection technology should be at the ...forefront of medical care worldwide. This study evaluated the usefulness of GeneSoC, a compact, high-speed reciprocal flow quantitative reverse transcription polymerase chain reaction system, for the detection of SARS-CoV-2. The results support the use of this system for the rapid identification of SARS-CoV-2. This approach can contribute to the strategic selection of initial management strategies for patients with COVID-19.
Longitudinal data are lacking to compare booster effects of Delta breakthrough infection versus third vaccine dose on neutralizing antibodies (NAb) against Omicron.
Participants were the staff of a ...national research and medical institution in Tokyo who attended serological surveys on June 2021 (baseline) and December 2021 (follow-up); in between, the Delta-dominant epidemic occurred. Of 844 participants who were infection-naïve and had received two doses of BNT162b2 at baseline, we identified 11 breakthrough infections during follow-up. One control matched to each case was selected from boosted and unboosted individuals. We compared live-virus NAb against Wild-type, Delta, and Omicron BA.1 across groups.
Breakthrough infection cases showed marked increases in NAb titers against Wild-type (4.1-fold) and Delta (5.5-fold), and 64% had detectable NAb against Omicron BA.1 at follow-up, although the NAb against Omicron after breakthrough infection was 6.7- and 5.2-fold lower than Wild-type and Delta, respectively. The increase was apparent only in symptomatic cases and as high as in the third vaccine recipients.
Symptomatic Delta breakthrough infection increased NAb against Wild-type, Delta, and Omicron BA.1, similar to the third vaccine. Given the much lower NAb against Omicron BA.1, infection prevention measures must be continued irrespective of vaccine and infection history while the immune evasive variants are circulating.
An optimization method combining deep reinforcement learning (DRL) and computational fluid dynamics (CFD) was developed, and its effectiveness and limitations are investigated. As a target to apply ...the method, an optimization problem to find geometry parameters of the wavy airfoil that maximizes the lift–drag ratio is set. Twin delayed deep deterministic policy gradient (TD3) is adopted as the DRL algorithm. The CFD code based on the standard scheme for viscous incompressible flows is used for the calculation of the lift–drag ratio. The neural networks learn a policy for improving the lift–drag ratio by changing the geometry parameters of the airfoil at the fixed angle of attack (AoA) of 0° and successfully achieve a maximum lift–drag ratio: the obtained final shape is almost the same as that acquired by the gradient method. However, when the global optimal solution is near the penalized region, the DRL has the disadvantage of tending to fall into local optima. The effects of several parameters of DRL, such as the reward function and the number of sample points in random exploration, are investigated. Moreover, by using a trained neural network at an AoA of 0°, a converged solution can be obtained more quickly for an AoA different from those of the trained case if an appropriate reward function is set. This indicates the possibility of transfer learning.
Although vaccines for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) disease 2019 (COVID-19) induce effective immune responses, vaccination with booster doses is necessary because of ...waning immunity. We conducted an open-label, non-randomized, single-arm study in adults in Japan to assess the immunogenicity and safety of a single booster dose of the KD-414 purified whole-SARS-CoV-2-virion inactivated vaccine candidate after vaccination with a primary series of BNT162b2. The primary endpoint was serum neutralizing activity at 7 days after booster injection compared with the primary series of BNT162b2. The SARS-CoV-2-structural protein-binding antibody level and T cell response against SARS-CoV-2-Spike (S) peptides were also examined as secondary endpoints, and safety profile assessments were conducted. Twenty subjects who participated in a previous study declined an injection of KD-414 (non-KD-414 group) and received a booster dose of BNT162b2 instead. The non-KD-414 group was compared to the KD-414 group as a secondary outcome. A single dose of KD-414 induced lower serum neutralizing activity against the wild-type virus within 7 days compared to after the primary series of BNT162b2 but significantly induced anti-SARS-CoV-2-S1-receptor-binding domain-binding immunoglobulin G (IgG) antibodies and SARS-CoV-2-S peptide-specific CD4
+
and CD8
+
T cell responses. Local or systemic symptoms were significantly lower in the participants who received KD-414 than in those who received BNT162b2 as the third COVID-19 vaccine dose. The present data indicate that a single booster dose of KD-414 induces a substantial immune response in BNT162b2-primed individuals and has a good safety profile, thereby supporting further clinical trials to identify rational targets.
We report on the ionic conductivity of Li
0.33
La
0.55
TiO
3
(LLTO) epitaxial films grown on the (100) and (111) surfaces of single crystal SrTiO
3
(STO) substrates at different oxygen partial ...pressures (from 1.33 to 26.66 Pa). The films are intended for use as solid electrolytes for all-solid-state Li-ion batteries, and the epitaxial growth for modeling the electrolyte single crystal properties. The LLTO films overall exhibit formation of the perovskite-based orthorhombic structure with the epitaxial cube-on-cube orientation for both (100)
STO
and (111)
STO
substrates. Room temperature ionic conductivity of the LLTO films measured by impedance spectroscopy slightly decreases with the oxygen partial pressure changing from 1.33 to 26.66 Pa and is in the range of 10
−4
to 10
−5
S cm
−1
. Complex impedance plots at different temperatures indicate that the conductivity in these epitaxial films is predominantly an intrinsic bulk property and exhibits distribution of relaxation time. Activation energies (
E
a
) for all the films were calculated employing the Arrhenius relationship and are between 0.30 eV and 0.40 eV, agreeing well with the reported values of bulk materials. Systematic difference in ionic conductivity between the (100)
STO
and (111)
STO
films is understood as being related to the difference in distribution of a "bottleneck" diffusion path. The measured conductivity of LLTO films indicates that these films can be used as a solid electrolyte in all-solid-state batteries.
We report on the ionic conductivity of Li
0.33
La
0.55
TiO
3
(LLTO) epitaxial films grown on the (100) and (111) surfaces of single crystal SrTiO
3
(STO) substrates at different oxygen partial pressures (from 1.33 to 26.66 Pa).
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