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We apply two methods to estimate the 21-cm bispectrum from data taken within the Epoch of Reionisation (EoR) project of the Murchison Widefield Array (MWA). Using data acquired with the Phase II compact array allows a direct bispectrum estimate to be undertaken on the multiple redundantly spaced triangles of antenna tiles, as well as an estimate based on data gridded to the uv-plane. The direct and gridded bispectrum estimators are applied to 21 h of high-band (167–197 MHz; z = 6.2–7.5) data from the 2016 and 2017 observing seasons. Analytic predictions for the bispectrum bias and variance for point-source foregrounds are derived. We compare the output of these approaches, the foreground contribution to the signal, and future prospects for measuring the bispectra with redundant and non-redundant arrays. We find that some triangle configurations yield bispectrum estimates that are consistent with the expected noise level after 10 h, while equilateral configurations are strongly foreground-dominated. Careful choice of triangle configurations may be made to reduce foreground bias that hinders power spectrum estimators, and the 21-cm bispectrum may be accessible in less time than the 21-cm power spectrum for some wave modes, with detections in hundreds of hours.
The second-order structure functions (SFs) of the velocity field, which characterize the velocity difference at two points, are widely used in research into non-reacting turbulent flows. In the present paper, the approach is extended in order to study the influence of combustion-induced thermal expansion on turbulent flow within a premixed flame brush. For this purpose, SFs conditioned to various combinations of mixture states at two different points (reactant–reactant, reactant–product, product–product, etc.) are introduced in the paper and a relevant exact transport equation is derived in the appendix. Subsequently, in order to demonstrate the capabilities of the newly developed approach for advancing the understanding of turbulent reacting flows, the conditioned SFs are extracted from three-dimensional (3-D) direct numerical simulation data obtained from two statistically 1-D planar, fully developed, weakly turbulent, premixed, single-step-chemistry flames characterized by significantly different (7.53 and 2.50) density ratios, with all other things being approximately equal. Obtained results show that the conditioned SFs differ significantly from standard mean SFs and convey a large amount of important information on various local phenomena that stem from the influence of combustion-induced thermal expansion on turbulent flow. In particular, the conditioned SFs not only (i) indicate a number of already known local phenomena discussed in the paper, but also (ii) reveal a less recognized phenomenon such as substantial influence of combustion-induced thermal expansion on turbulence in constant-density unburned reactants and even (iii) allow us to detect a new phenomenon such as the appearance of strong local velocity perturbations (shear layers) within flamelets. Moreover, SFs conditioned to heat-release zones indicate a highly anisotropic influence of combustion-induced thermal expansion on the evolution of small-scale two-point velocity differences within flamelets, with the effects being opposite (an increase or a decrease) for different components of the local velocity vector.
We formulate and conduct the time-integration of time evolution equation for the giant molecular cloud mass function (GMCMF) including the cloud-cloud collision (CCC) effect. Our results show that the CCC effect is only limited in the massive-end of the GMCMF and indicate that future high resolution and sensitivity radio observations may constrain giant molecular cloud (GMC) timescales by observing the GMCMF slope in the lower mass regime.
The mode of onset and the course of schizophrenia illness exhibit substantial individual variations. Previous studies have pointed out that the mode of onset affects the duration of untreated psychosis (DUP) and clinical outcomes, such as cognitive and social functioning. This study attempted to clarify the association between the DUP and clinical features, taking the different modes of onset into consideration, in a prospective longitudinal study examining patients with first-episode schizophrenia.
This study was conducted in six areas of Japan. Patients with first-episode schizophrenia were followed for over 18 months. Cognitive function, psychopathology, and social functioning were assessed at baseline and at 6, 12, and 18-month follow-up points.
We identified 168 patients and sufficient information was available to determine the DUP and the mode of onset for 156 patients (92.9%): 79 had an acute onset, and 77 had an insidious onset. The DUP was significantly associated with quality of life (QOL), social functioning, and cognitive function at most of the follow-up points in the insidious-onset group. The DUP and negative symptoms at baseline were significant predictors of cognitive function at the 18-month follow-up in the insidious-onset group.
The present results further support the hypothesis that the DUP affects QOL, social functioning, and cognitive function over the course of illness, especially in patients with an insidious onset. Effective strategies for detecting and caring for individuals with insidious onset early during the course of schizophrenia will be essential for achieving a full patient recovery.
Sustained friction drag reduction and heat transfer augmentation are simultaneously achieved in a fully developed channel flow where the averaged transport equations and wall boundary conditions for momentum and heat have identical form. Zero-net-mass-flux wall blowing and suction is assumed as a control input and its spatio-temporal distribution is determined based on optimal control theory. When the root-mean-square value of the control input is 5 % of the bulk mean velocity, the friction drag is decreased by 24 % from the uncontrolled value, whereas the heat transfer is more than doubled. Optimizations with different amplitudes of the control input and different Reynolds numbers reveal that the optimal control inputs commonly exhibit the property of a downstream travelling wave, whose wavelength is ∼250 in wall units and phase velocity is ∼30 % of the bulk mean velocity. Detailed analyses of the controlled velocity and thermal fields show that the travelling wave input contributes to dissimilar heat transfer enhancement through two distinct mechanisms, i.e. direct modification of the coherent velocity and thermal fields and an indirect effect on the random fields. The present results show that the divergence-free velocity vector and the conservative scalar are essentially different, and this is a key to achieving dissimilar heat transfer enhancement in turbulent shear flows.
Delirium and dementia are highly interrelated. However, few comprehensive epidemiological studies have examined this altered state of consciousness superimposed on dementia. We investigated the frequency of delirium in patients with dementia, its prevalence in patients with each dementia type, and its association with cerebrovascular disease (CVD) in patients with neurodegenerative dementias.
We studied 261 consecutive outpatients in the memory clinic of a psychiatric hospital between April 2010 and September 2011. All patients underwent routine laboratory tests and computed tomography (CT), and their Mini-Mental State Examination, Neuropsychiatric Inventory (NPI), Physical Self-Maintenance Scale (PSMS), and Delirium Rating Scale – Revised 98 scores were recorded. The diagnosis of delirium was based on the Diagnostic and Statistical Manual of Mental Disorders, fourth edition, text revision. CVD was detected by CT.
Among the 206 patients with dementia, delirium was present in 40 (19.4%). The proportion of patients who experienced episodes of delirium was 14.7% in the Alzheimer's disease, 34.4% in the vascular dementia, 31.8% in the dementia with Lewy bodies, and none in frontotemporal lobar degeneration. Delirium was frequently observed in patients with dementia and CVD. The NPI total and agitation subscale scores were significantly higher in dementia patients with delirium than in those without delirium. PSMS scores were significantly lower for patients with delirium than for patients without delirium.
The frequency of delirium varies with each dementia type. In addition, delirium decreases activities of daily living, exaggerates behavioral and psychological symptoms dementia, and is associated with CVD in patients with neurodegenerative dementias.
KNbO3 thick films were deposited on (100)c SrRuO3//(100)SrTiO3 substrates at 240 °C for 3 h by hydrothermal method. Film thickness increased linearly with increasing the deposition number of times and 130 μm thickness was achieved by the 6 time deposition. XRD analysis showed the growth of epitaxial orthorhombic films with the mixture orientation of (100), (010) and (001). Cross-sectional SEM observation showed that the 130 μm-thick film was dense and no obvious voids inside the film. In addition, the crystal structure change along film thickness direction was not detected from the cross-sectional Raman spectral observation.
A wide range of applicability of the Reynolds analogy between turbulent momentum and heat transport implies inherent difficulty in diminishing or enhancing skin friction and heat transfer independently. In the present study, we introduce suboptimal control theory for achieving a dissimilar control of enhancing heat transfer, while keeping the skin friction not increased considerably in a fully developed channel flow. The Fréchet differentials clearly show that the responses of velocity and temperature fields to wall blowing/suction are quite different, due to the fact that the velocity is a divergence-free vector field while the temperature is a conservative scalar field. This essential difference allows us to achieve dissimilar control even in flows where the averaged momentum and energy transport equations have an identical form. It is also found that the resultant optimized mode of control input exhibits a streamwise travelling-wave-like property. By exploring the phase relationship between the travelling-wave-like control input and the velocity and thermal fields, we reveal that such control input contributes to dissimilar heat transfer enhancement via two different mechanisms, i.e. direct modification of the coherent components of the Reynolds shear stress and the turbulent heat flux, and indirect effects on the incoherent components, through modification of the mean velocity and temperature profiles. Based on these results, a simple open-loop strategy for dissimilar control is proposed and assessed.
To examine the usefulness of a three-dimensional model for surgical navigation of cholesteatoma.
Materials and method:
A three-dimensional model was prototyped using selective laser sintering. Based on detailed computed tomography data, powder layers were laser-fused and accumulated to create a three-dimensional structure. The computed tomography threshold was adjusted to simultaneously replicate bony structures and soft tissues.
The cholesteatoma, major vessels and bony structures were well replicated. This laser-sintered model was used to aid surgery for recurrent cholesteatoma. The cholesteatoma, which extended from the hypotympanum through the styloid process sheath and the internal carotid artery sheath, was removed safely via a minimal skin incision.
The laser-sintered model was useful for surgical planning and navigation in a cholesteatoma case involving complex bony structures and soft tissue.
Stability of Pd-Co-Ni-Cu-P metallic glass was investigated in terms of free energy using first principle cluster calculations, thermal analysis, and photoemission spectroscopy measurements. We found that the internal energy of the Pd-based metallic glasses is dominated by the electronic structure near the Fermi level. The analyses on the electronic structure and local atomic arrangements indicate that the substitution of cobalt or a hypothetical atom Co0.5Cu0.5 for nickel in the Pd40Ni40P20 metallic glass decreases the free energy of the Pd-Ni-P metallic glass by increasing entropy without altering significantly internal energy. On the basis of the idea mentioned above, we prepared Pd28Co24Ni24P24, Pd25Co25Ni25P25 and Pd40Co40/3Ni40/3Cu40/3P20 metallic glasses. These metallic glasses certainly showed the nearly highest TX, which directly reflect the activation energy against crystallization, among the Pd-based metallic glasses ever reported.
We present the high-resolution 12CO(J = 1 − 0), 13CO(J = 1 − 0) and 12CO(J = 3 − 2) maps toward a GMA located on the southern arm region of M31 using Nobeyama 45 m and ASTE 10 m telescopes. The GMA consists of two velocity-components, i.e., red and blue. The blue component shows a strong and narrow peak, whereas the red one shows a weak and broad profile. The red component has a lower 12CO(J = 1 − 0)/13CO(J = 1 − 0) ratio (~ 5) than that of the blue one (~ 16), indicating that the red component is denser than the blue one. The red component could be the decelerated gas if we consider the galactic rotational velocity in this region. We suggest that the red component is “post shock” dense gas decelerated due to a spiral density wave. This could be observational evidence of dense molecular gas formation due to galactic shock by spiral density waves.
We also present results from on-going observations toward NGC 604, which is the supergiant HII region of M33, using Nobeyama 45 m and ASTE 10 m telescopes. The ratio of 12CO(J = 3 − 2) to 12CO(J = 1 − 0) ranges from 0.3 to 1.2 in NGC 604. The 12CO(J = 1 − 0) map shows the clumpy structure while 12CO(J = 3 − 2) shows a strong peak near to the central star cluster of NGC 604. The high ratio gas is distributed on the arc-like or shell-like structure along with Hα emission and HII region detected by radio continuum. These suggest that the dense gas formation and second generation star formation occur in the surrounding gas compressed by the stellar wind and/or supernova in central star cluster.
The interaction process between fast heavy ions and dense plasma
was experimentally investigated. We injected 4.3-MeV/u or
6.0-MeV/u iron ions into a z-pinch-discharge helium
plasma and measured the energy loss of the ions by the time
of flight method. The energy loss of 4.3-MeV/u ions fairly
agreed with theoretical prediction when the electron density
of the target was on the order of 1018 cm−3.
With increasing electron density beyond 1019
cm−3, the difference between the experiment
and the theory became remarkable; the experimental energy loss
was 15% larger than the theoretical value at the peak density.
For 6.0-MeV/u ions, the deviation from the theory appeared
even at densities below 1019 cm−3.
These discrepancies indicated that density effects such as ladderlike
ionization caused the enhancement of the projectile mean charge in the
A new magneto-optical (MO) imaging system for high-throughput characterization of combinatorial magnetic thin films has been developed. The instrument allows us to measure both Faraday rotation and ellipticity maps at various wavelengths (400 nm∼1000 nm), different magnetic fields (0∼2000 G), and different temperatures (12 K∼300 K) for wide variety of materials. We used the magnetic circular dichroism (MCD) modulation technique to map MO properties, relatively free from substrate effects. The superiority of this system is that magnetic hysteresis curves of numerous specimens with different compositions prepared by the combinatorial technique can be simultaneously measured at one sweep of magnetic field, providing an efficient characterization method for combinatorial magnetic materials. We also confirmed that the system possesses enough spatial resolution and sensitivity for detecting MO signals of individual pixels contained in a combinatorial library.
A combinatorial material synthesis with temperature gradient heating system was employed to optimizing growth parameters for oxide growth on Si substrate. From the obtained results, it was found the dielectric property depends on the growth temperature as well as the composition. The interface structures were investigated by high resolution electron microscopy with a series of specimens fabricated by micro sampling method. The results showed that amorphous oxide region and SiO2 layer were formed at the interface. It was speculated that the amorphous oxide region contributed to the reduction of the dielectric property. To avoid the amorphous and SiO2 formation at the oxide/Si interface, a few kinds of intermediate layers were inserted and tested to find the possibility of abrupt interface formation.
Magnetic films for miniaturization of planar inductors operating at GHz frequencies require high resistivity and high ferro-magnetic resonance frequency. Y type magnetoplumbite Ba2Co2Fe12O22(Co2Y) is a candidate material to meet such requirements because it has about 10 &m resistivity and resonance frequency higher than 2 GHz. Recently we succeeded in the fabrication of Co2Y epitaxial thin film on MgAl2O4 substrate by combinatorial pulsed laser deposition technique . Here, we report on the magnetic and dielectric properties of this film. The DC resistivity of the film was 7.5 &m. The dielectric constant at 1.25 GHz was measured by a microwave microscope to be 11.0. An easy axis coercive force and saturation magnetization were about 145 Oe and 2000 Gauss respectively, being close to those of bulk sample. Furthermore, the magnetic micro domain structures of Co2Y epitaxial thin films were observed by a scanning SQUID microscope.
The discovery of superconductivity in MgB2 has been followed by many papers reporting attractive thin film properties. In most cases these have involved the deposition of precursor films followed by in-situ or ex-situ post annealing in a Mg-rich atmosphere. Although simple device structures have been fabricated from such films, it is desirable for a number of reasons that a heterostructure device technology be developed. Heterostructure growth is likely to require in-situ growth, preferably without post-annealing. To achieve this, low oxygen and high Mg background pressures are required in the vicinity of the sample. By using a novel heater geometry we have been able to grow superconducting MgB2 films from Mg-rich targets at temperatures below 500 °C. This paper reports the growth method, and structural and electrical characterization of the films.