To send content items to your account,
please confirm that you agree to abide by our usage policies.
If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account.
Find out more about sending content to .
To send content items to your Kindle, first ensure email@example.com
is added to your Approved Personal Document E-mail List under your Personal Document Settings
on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part
of your Kindle email address below.
Find out more about sending to your Kindle.
Note you can select to send to either the @free.kindle.com or @kindle.com variations.
‘@free.kindle.com’ emails are free but can only be sent to your device when it is connected to wi-fi.
‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.
Space Infrared Telescope for Cosmology and Astrophysics (SPICA), the cryogenic infrared space telescope recently pre-selected for a ‘Phase A’ concept study as one of the three remaining candidates for European Space Agency (ESA's) fifth medium class (M5) mission, is foreseen to include a far-infrared polarimetric imager [SPICA-POL, now called B-fields with BOlometers and Polarizers (B-BOP)], which would offer a unique opportunity to resolve major issues in our understanding of the nearby, cold magnetised Universe. This paper presents an overview of the main science drivers for B-BOP, including high dynamic range polarimetric imaging of the cold interstellar medium (ISM) in both our Milky Way and nearby galaxies. Thanks to a cooled telescope, B-BOP will deliver wide-field 100–350
m images of linearly polarised dust emission in Stokes Q and U with a resolution, signal-to-noise ratio, and both intensity and spatial dynamic ranges comparable to those achieved by Herschel images of the cold ISM in total intensity (Stokes I). The B-BOP 200
m images will also have a factor
30 higher resolution than Planck polarisation data. This will make B-BOP a unique tool for characterising the statistical properties of the magnetised ISM and probing the role of magnetic fields in the formation and evolution of the interstellar web of dusty molecular filaments giving birth to most stars in our Galaxy. B-BOP will also be a powerful instrument for studying the magnetism of nearby galaxies and testing Galactic dynamo models, constraining the physics of dust grain alignment, informing the problem of the interaction of cosmic rays with molecular clouds, tracing magnetic fields in the inner layers of protoplanetary disks, and monitoring accretion bursts in embedded protostars.
This is a copy of the slides presented at the meeting but not formally written up for the volume.
The interface electronic structure of transition metal oxides has attracted considerable attention in recent years. Given the versatile physical properties of these materials, and the interest in developing novel functional devices unattainable by conventional semiconductors, understanding interface barrier formation and control is a central issue. Among various interface structures, single interface junctions are the simplest structure for their study, and their transport properties can provide much of the essential information for depiction of the interface electronic structure. Recently, magnetic field dependent current-voltage (I-V) and capacitance-voltage (C-V) characteristics were reported for a junction between oxygen deficient manganite (La0.7Sr0.3MnO3-ä) and 0.01wt% Nb doped SrTiO3 (Nb:STO). By contrast, no magnetic field dependence was observed for the stoichiometric junction (La0.7Sr0.3MnO3 / Nb:STO) . La0.7Sr0.3MnO3-ä is a ferromagnetic metal with a Curie temperature lower than the stoichiometric counterpart, and Nb:STO is an n-type band semiconductor. The magnetic field dependence of the I-V and C-V are contrary to the expectation from the Zeeman effect . To elucidate the origin of the magnetic field dependence observed, we used internal photoemission (IPE) to directly probe the evolution of the Schottky barrier height. In this technique, the reverse junction current is monitored while the sample is illuminated with monochromatic light of varying wavelength. IPE is a direct, reliable method for the determination of Schottky barrier heights since the measurement is free from external electric field, eliminating any complexity associated with bias dependent effects observed in the case of I-V and C-V. In addition, its compatibility with external magnetic field makes this method especially desirable for investigating interface electronic structures involving magnetically sensitive materials. Junctions with different oxygen stoichiometry were grown by pulsed laser deposition of a La0.7Sr0.3MnO3 target on Nb:STO substrates, and their I-V, C-V and IPE characteristics were measured under magnetic field. Magnetic field dependence was observed by all three techniques for La0.7Sr0.3MnO3-ä / Nb:STO, whereas they were field independent for La0.7Sr0.3MnO3 / Nb:STO. In La0.7Sr0.3MnO3-δ / Nb:STO, the barrier height determined from IPE measurements significantly decreased with magnetic field, which is consistent with the I-V and C-V results. The origin of the magnetic field dependent Schottky barrier height will be discussed.  N. Nakagawa et al., App. Phys. Lett. 87, 241919 (2005).
This is a copy of the slides presented at the meeting but not formally written up for the volume.
Description: Semiconductor physics contains a rich body of theory and working designs. However, their material properties seem to be reaching their limits. Perovskite oxides on the other hand have abundant physical properties, but are still under active investigation. The advent of RHEED-monitoring of pulsed laser deposition allows for the fabrication of structures with single unit cell (4 Å) thick layers. In this way we may be able to fabricate quantum well structures for both applications and fundamental investigations. Superlattices of the Mott insulator LaTiO3 (LTO) and the band gap insulator SrTiO3 (STO) form such a structure. The superlattices are metallic, both as-grown and post-annealed . This has been attributed to the existence of metallic states at the interfaces between LTO and STO . At these interfaces the electron density is found to extend about 10 Å into the STO. However, theoretically, the required length scale for quantum confinement is of the order of 4 Å. A possible way to increase this confinement is to use a buffer material with a larger band gap than that of LTO (similar to semiconductor band gap engineering) and/or with a lower dielectric constant . LaAlO3 (LAO) is such a material (ΔELAO = 5.6 eV vs. ΔESTO = 3.2 eV, εLAO = 24 vs. εSTO = 300). Here we report on the growth of LTO/LAO superlattices on STO substrates. As-grown superlattices of LTO/LAO are metallic, while post-annealing turns them insulating. This may be explained from a disorder-order transition in a 2D Mott-Hubbard model . XPS and EELS measurements of the titanium valence show interesting differences for LTO layers close to and far away from the sample surface. The former, for thin LAO capping layers, show the presence of Ti4+ while the latter only have Ti3+. Hard XPS of samples with varying capping layer thickness shows an exponential dependence of the Ti3+ contents on a length scale of about 5 unit cells.  A. Ohtomo et al., Nature 419, 378-380 (2002).  S. Okamoto & A.J. Millis, Phys. Rev. B 70, 075101 (2004).  D. Heidarian & N. Trivedi, Phys. Rev. Lett. 93, 126401 (2004).
To investigate the association between suicide death and serum cholesterol levels as measured at times close to suicide death.
We conducted a nested case-control study of 41 cases of suicide deaths and 205 matched controls with serum total cholesterol (TC) levels till 3 years before suicide death in a large cohort of Japanese workers.
Individuals in the lowest versus highest tertile/predefined category of TC in a Japanese working population had a three- to four-fold greater risk of suicide death. Each 10 mg/dl decrement of average TC was associated with an 18% increased chance of suicide death (95% confidence interval, 2–35%). Similar results were found for TC levels at each year.
These results suggest that a low serum TC level in recent past is associated with an increased risk of suicide death.
The purpose of this study was to examine whether vehicle type based on size (car vs. other = truck/van/SUV) had an impact on the speeding, acceleration, and braking patterns of older male and female drivers (70 years and older) from a Canadian longitudinal study. The primary hypothesis was that older adults driving larger vehicles (e.g., trucks, SUVs, or vans) would be more likely to speed than those driving cars. Participants (n = 493) had a device installed in their vehicles that recorded their everyday driving. The findings suggest that the type of vehicle driven had little or no impact on per cent of time speeding or on the braking and accelerating patterns of older drivers. Given that the propensity for exceeding the speed limit was high among these older drivers, regardless of vehicle type, future research should examine what effect this behaviour has on older-driver road safety.
Parotid gland carcinoma is a rare and complicated histopathological classification. Therefore, assembling a sufficient number of cases with long-term outcomes in a single institute can present a challenge.
The medical records of 108 parotid gland carcinoma patients who were treated at Kyushu University Hospital, Fukuoka, Japan, between 1983 and 2014 were reviewed. The survival outcomes were analysed according to clinicopathological findings.
Forty-six patients had low clinical stage tumours (I–II), and 62 patients had high clinical stage tumours (III–IV). Fifty-two, 10 and 46 patients had low-, intermediate- and high-grade tumours, respectively. Twenty-seven of 65 cases had positive surgical margins. In high clinical stage and intermediate- to high-grade tumours, adjuvant radiation therapy was correlated with local recurrence-free survival (p = 0.0244). Intermediate- to high-grade tumours and positive surgical margins were significantly associated with disease-specific survival in multivariate analysis (p = 0.0002 and p = 0.0058).
The results of this study show that adjuvant radiation therapy is useful for improved local control in patients with high clinical stage and intermediate- to high-grade tumours.
An expert government committee in Japan decided to revise the chance of a Nankai Trough earthquake in the next 30 years from 70% to between 70 and 80% in 2017. If a mega-earthquake occurs, medical institutions in disaster regions are required to perform self-contained activities during the super-acute phase. Human damage varies depending on whether medical functions can be sustained, particularly in rural areas and isolated islands. Here we examined actual situations.
To identify the issues of a disaster medical system in rural areas and isolated islands that need solving.
Regarding disaster preparedness planning, we conducted a survey on 10 hospitals undesignated as disaster key hospitals of remote area medical care bases (survey group), and 69 hospitals designated as disaster key hospitals (control group) in three prefectures in the Tokai region (Aichi, Mie, and Shizuoka).
We received responses from four hospitals in the survey group and 52 hospitals in the control group. The hospitals in the survey group responded that they could accept 74 severe casualties and 85 moderate casualties. We identified problems such as insufficient stockpiling of fuel, water, and oxygen, and lack of a prioritized lifeline supply contract.
It was predicted that human damage would be relatively minor given smaller populations in rural areas and isolated islands in the Tokai region. However, the number of patients would exceed their acceptance capacity. Moreover, the system for sustaining infrastructure is not adequate for providing medical services. Thus, it was indicated that these regions would be isolated in terms of disaster measures. It is imperative to establish a disaster medical system in rural areas and isolated islands that lack adequate disaster medical systems to manage Nankai Trough earthquakes.
The oscillation from a linear relation in the 20 vs. sin2ψ diagram has been a most important problem in X-ray stress measurement. There are, therefore, a number of papers concerned with the X-ray elastic constant, lattice strains under stresses and evaluation of stresses of textured materials.
The purpose of the present study is to analyze the three-dimensional orientation distribution of steel sheets by means of the Vector method proposed by Ruer and Baro, and to calculate the elastic modulus of textured sheets by means of a finite element method (FEM) using the three-dimensional orientation distribution, and then to calculate the strain/stress ratios vs. the directions defined by the angles between the specimen normal and the normal to the diffracting planes.
With the recent discovery of a dozen dusty star-forming galaxies and around 30 quasars at z > 5 that are hyper-luminous in the infrared (μ LIR > 1013 L⊙, where μ is a lensing magnification factor), the possibility has opened up for SPICA, the proposed ESA M5 mid-/far-infrared mission, to extend its spectroscopic studies toward the epoch of reionisation and beyond. In this paper, we examine the feasibility and scientific potential of such observations with SPICA’s far-infrared spectrometer SAFARI, which will probe a spectral range (35–230 μm) that will be unexplored by ALMA and JWST. Our simulations show that SAFARI is capable of delivering good-quality spectra for hyper-luminous infrared galaxies at z = 5 − 10, allowing us to sample spectral features in the rest-frame mid-infrared and to investigate a host of key scientific issues, such as the relative importance of star formation versus AGN, the hardness of the radiation field, the level of chemical enrichment, and the properties of the molecular gas. From a broader perspective, SAFARI offers the potential to open up a new frontier in the study of the early Universe, providing access to uniquely powerful spectral features for probing first-generation objects, such as the key cooling lines of low-metallicity or metal-free forming galaxies (fine-structure and H2 lines) and emission features of solid compounds freshly synthesised by Population III supernovae. Ultimately, SAFARI’s ability to explore the high-redshift Universe will be determined by the availability of sufficiently bright targets (whether intrinsically luminous or gravitationally lensed). With its launch expected around 2030, SPICA is ideally positioned to take full advantage of upcoming wide-field surveys such as LSST, SKA, Euclid, and WFIRST, which are likely to provide extraordinary targets for SAFARI.
We quantified an absolute imbalance of the medical risks and the support needs for children at each disaster-based hospital in Kanagawa immediately following the occurrence of a large earthquake by using the risk resource ratio (RRR) and need for medical resources (NMR).
The RRR and NMR of 33 disaster-based hospitals were estimated through dividing the estimated number of pediatric victims by the number of critically patients. We calculated the ratio of the NMR of each hospital.
The total number of pediatric victims in Kanagawa was estimated at 8,391. The total number of vacant beds for pediatric victims was 352. The median RRR and NMR of the total number of pediatric victims were 27 and 224. The median RRR and NMR of the number of critically ill pediatric patients were 27 and 12.
The absolute imbalance of the RRR and NMR for children in Kanagawa was quantified. This suggests that we might embark on preparedness strategies for children in advance. (Disaster Med Public Health Preparedness. 2018;13:672–676)
It is generally accepted that oceanic plate subduction has occurred along the eastern margin of Asia since about 500 Ma ago. Therefore, the Japanese Islands have a >500 Ma history of oceanic plate subduction in their geological records. In this paper, the accretionary history of the Japanese Islands is divided into six main stages based on the mode and nature of tectonic events and the temporal gaps in the development of accretionary processes. In the first stage, oceanic plate subduction and accretion started along the margin of Gondwana. After detachment of the North and South China blocks in Devonian time, accretionary complexes developed along island arcs offshore of the South and North China blocks. After the formation of back arc basins such as the Japan Sea, accretionary processes occurred only along the limited convergent margin, e.g. Nankai Trough. Detrital zircons of sandstones revealed the accretionary history of Japan. An evaluation of a comprehensive dataset on detrital zircon populations shows that the observed temporal gaps in the development of the Japanese accretionary complexes were closely related to the intensity of igneous activity in their provenance regions. Age distributions of detrital zircons in the accretionary complexes of Japan change before and after the Middle Triassic period, when the collision of the South and North China blocks occurred.
Measurements in the infrared wavelength domain allow direct assessment of the physical state and energy balance of cool matter in space, enabling the detailed study of the processes that govern the formation and evolution of stars and planetary systems in galaxies over cosmic time. Previous infrared missions revealed a great deal about the obscured Universe, but were hampered by limited sensitivity.
SPICA takes the next step in infrared observational capability by combining a large 2.5-meter diameter telescope, cooled to below 8 K, with instruments employing ultra-sensitive detectors. A combination of passive cooling and mechanical coolers will be used to cool both the telescope and the instruments. With mechanical coolers the mission lifetime is not limited by the supply of cryogen. With the combination of low telescope background and instruments with state-of-the-art detectors SPICA provides a huge advance on the capabilities of previous missions.
SPICA instruments offer spectral resolving power ranging from R ~50 through 11 000 in the 17–230 μm domain and R ~28.000 spectroscopy between 12 and 18 μm. SPICA will provide efficient 30–37 μm broad band mapping, and small field spectroscopic and polarimetric imaging at 100, 200 and 350 μm. SPICA will provide infrared spectroscopy with an unprecedented sensitivity of ~5 × 10−20 W m−2 (5σ/1 h)—over two orders of magnitude improvement over what earlier missions. This exceptional performance leap, will open entirely new domains in infrared astronomy; galaxy evolution and metal production over cosmic time, dust formation and evolution from very early epochs onwards, the formation history of planetary systems.
For fabricating photovoltaic BaSi2 films with controlled carrier density and suppressed oxidation by thermal evaporation, the mechanism determining the film composition from incongruently evaporated BaSi2 must be elucidated. We investigated the effects of source premelting, substrate temperature, and thickness on the structural and electrical properties of evaporated BaSi2 films. It is found by room-temperature deposition that the vapor composition continuously changes from being Ba-rich to being Si-rich. Source premelting suppresses the deposition of Ba-rich vapor. Deposition at 600–700 °C shows that BaSi2 forms through the mutual diffusion of Ba and Si, followed by surface oxidation by residual gas. Surface oxidation can be suppressed by a-axis-oriented growth. By changing the film thickness, the optimum thickness to obtain homogeneous films with suppressed oxidation is revealed. Sufficient diffusion leads to high film resistivities and low electron densities, which demonstrates a close relationship between the film composition and the electrical properties.
A novel preparation method of B-doped p-type BaSi2 (p-BaSi2) is proposed to realize heterojunction crystalline Si solar cells with p-BaSi2. The method consists of thermal evaporation of BaSi2 on B-doped amorphous Si (a-Si). In this study, the effect of a-Si interlayers and substrate temperature during BaSi2 evaporation on the electrical characteristics and crystalline quality of the evaporated films were investigated. While no cracks were found in the BaSi2 films formed using hydrogenated a-Si deposited by plasma enhanced chemical vapor deposition (PECVD), the films formed with sputtered a-Si have cracks. In addition, BaSi2 films formed with a 600 °C substrate temperature using PECVD a-Si showed p-type characteristics. After a post-deposition anneal at 800 °C for 5 minutes, the film hole density was measured at 1.3×1019 cm-3 and boron was found to be uniformly distributed throughout the film. These results show that the proposed method using PECVD is promising to obtain p-BaSi2 thin films with high hole density for p-BaSi2/n-type crystalline Si heterojunction solar cells.
The SPICA mid- and far-infrared telescope will address fundamental issues in our understanding of star formation and ISM physics in galaxies. A particular hallmark of SPICA is the outstanding sensitivity enabled by the cold telescope, optimised detectors, and wide instantaneous bandwidth throughout the mid- and far-infrared. The spectroscopic, imaging, and polarimetric observations that SPICA will be able to collect will help in clarifying the complex physical mechanisms which underlie the baryon cycle of galaxies. In particular, (i) the access to a large suite of atomic and ionic fine-structure lines for large samples of galaxies will shed light on the origin of the observed spread in star-formation rates within and between galaxies, (ii) observations of HD rotational lines (out to ~10 Mpc) and fine structure lines such as [C ii] 158 μm (out to ~100 Mpc) will clarify the main reservoirs of interstellar matter in galaxies, including phases where CO does not emit, (iii) far-infrared spectroscopy of dust and ice features will address uncertainties in the mass and composition of dust in galaxies, and the contributions of supernovae to the interstellar dust budget will be quantified by photometry and monitoring of supernova remnants in nearby galaxies, (iv) observations of far-infrared cooling lines such as [O i] 63 μm from star-forming molecular clouds in our Galaxy will evaluate the importance of shocks to dissipate turbulent energy. The paper concludes with requirements for the telescope and instruments, and recommendations for the observing strategy.
Thermal evaporation is a simple method to fabricate a BaSi2 film, a new solar cell material consisting of earth-abundant elements. In this study, we optimized the evaporation process and suppressed near-interface oxidation in evaporated BaSi2 films on Si(100) substrates, which has been detected in previous studies. Composition depth profiles determined by Auger electron spectroscopy show the decrease of oxygen concentration near the interface to the background level by optimizing the source pre-melting condition. By reducing oxygen concentration, the BaSi2 film becomes more preferentially oriented toward  as long as the deposition rate is not changed, as evidenced by X-ray diffraction. It is also shown that the rectification behavior of n-BaSi2/p+-Si diodes improves by suppressing the near-interface oxidation.
A complex mechanism of interfacial oxygen scavenging is revealed by electron energy-loss spectroscopy (EELS) for a resistive switching oxide of SrTiO3 with a scavenging layer of Ta. When Ta thin layer is inserted at one of the interfaces of Pt/SrTiO3/Pt structure, a large reduction of electrical resistance is induced for the structure, and oxygen defects are introduced at the interfacial part of SrTiO3. In the resistance decrease by voltage applications, simultaneous occurrence of oxidation and reduction of Ta scavenging layer is shown by EELS analyses from the low-loss spectra. The EELS and scanning transmission electron microscopy observations demonstrate that oxygen scavenging by Ta layer is an interfacial phenomenon where the redox reactions occur at the whole part of the interface. In addition, Pt electrode of the structure, which is chemically inert for oxidation, is revealed to have significant effects in the scavenging processes.