Sophia University

About: Sophia University is a education organization based out in Tokyo, Japan. It is known for research contribution in the topics: Nonlinear system & Catalysis. The organization has 4986 authors who have published 7657 publications receiving 106567 citations. The organization is also known as: Jōchi Daigaku.

Drawing Phase Diagrams of Random Quantum Systems by Deep Learning the Wave Functions

Abstract: Applications of neural networks to condensed matter physics are becoming popular and beginning to be well accepted. Obtaining and representing the ground and excited state wave functions are exampl...

Anisotropic enhancement of turbulence in large-scale, low-intensity turbulent premixed propane–air flames

Abstract: The density change across premixed flames propagating in turbulent flows modifies the turbulence. The nature of that modification depends on the regime of turbulent combustion, the burner design, the orientation of the turbulent flame and the position within the flame. The present study addresses statistically stationary turbulent combustion in the flame-sheet regime, in which the laminar-flame thickness is less than the Kolmogorov scale, for flames stabilized on a vertically oriented cylindrical burner having fully developed upward turbulent pipe flow upstream from the exit. Under these conditions, rapidly moving wrinkled laminar flamelets form the axisymmetric turbulent flame brush that is attached to the burner exit. Predictions have been made of changes in turbulence properties across laminar flamelets in such situations, but very few measurements have been performed to test the predictions. The present work measures individual velocity changes and changes in turbulence across flamelets at different positions in the turbulent flame brush for three different equivalence ratios, for comparison with theory. The measurements employ a three-element electrostatic probe (EP) and a two-component laser-Doppler velocimeter (LDV). The LDV measures axial and radial components of the local gas velocity, while the EP, whose three sensors are located in a vertical plane that passes through the burner axis, containing the plane of the LDV velocity components, measures arrival times of flamelets at three points in that plane. From the arrival times, the projection of flamelet orientation and velocity on the plane are obtained. All of the EP and LDV sensors are located within a fixed volume element of about 1 mm diameter to provide local, time-resolved information. The technique has the EP advantages of rapid response and good sensitivity and the EP disadvantages of intrusiveness and complexity of interpretation, but it is well suited to the type of data sought here. Theory predicts that the component of velocity tangent to the surface of a locally planar flamelet remains constant in passing through the flamelet. The data are consistent with this prediction, within the accuracy of the measurement. The data also indicate that the component of velocity normal to the flamelet, measured with respect to the flamelet, tends to increase in passing through the flamelet, as expected. The flamelets thereby can generate anisotropy in initially isotropic turbulence. They also produce differences in turbulent spectra conditioned on unburnt or burnt gas. Local modifications of turbulence by flamelets thus are demonstrated experimentally. The modifications are quantitatively different at different locations in the turbulent flame brush but qualitatively similar in that the turbulence is enhanced more strongly in the radial direction than in the axial direction at all positions in these flames.

Examining purchasing reforms towards universal health coverage by the National Hospital Insurance Fund in Kenya

Abstract: Kenya has prioritized the attainment of universal health coverage (UHC) through the expansion of health insurance coverage by the National Hospital Insurance Fund (NHIF). In 2015, the NHIF introduced reforms in premium contribution rates, benefit packages, and provider payment methods. We examined the influence of these reforms on NHIF’s purchasing practices and their implications for strategic purchasing and health system goals of equity, efficiency and quality. We conducted an embedded case study with the NHIF as the case and the reforms as embedded units of analysis. We collected data at the national level and in two purposively selected counties through 41 in-depth interviews with health financing stakeholders, facility managers and frontline providers; 4 focus group discussions with 51 NHIF members; and, document reviews. We analysed the data using a Framework approach. The new NHIF reforms were characterized by weak purchasing actions. Firstly, the new premium contribution rates were inadequately communicated and unaffordable for certain citizen groups. Secondly, while the new benefit packages were reported to be based on service needs, preferences and values of the population, they were inadequately communicated and unequally distributed across different citizen groups. In addition, the presence of service delivery infrastructure gaps in public healthcare facilities and the pro-urban and pro-private distribution of contracted health facilities compromised delivery of, and access to, these new services. Lastly, the new provider payment methods and rates were considered inadequate, with delayed payments and weak links to financial accountability mechanisms which compromised their ability to incentivize equity, efficiency and quality of healthcare delivery. While NHIF sought to expand population and service coverage and reduce out-of-pocket payments with the new reforms, weaknesses in the reforms’ design and implementation limited NHIF’s purchasing actions with negative implications for the health system goals of equity, efficiency and quality. For the reforms to accelerate the country’s progress towards UHC, policy makers at the NHIF and, national and county government should make deliberate efforts to align the design and implementation of such reforms with strategic purchasing actions that are aimed at improving health system goals.

Regio- and diastereocontrol in carbonyl allylation by 1-halobut-2-enes with Tin(II) halides

Abstract: Regio- and diastereoselective carbonyl allylations of 1-halobut-2-enes with tin(II) halides are described. Tin(II) bromide in a dichloromethane−water biphasic system is an effective reagent for unusual α-regioselective carbonyl allylation of 1-bromobut-2-ene to produce 1-substituted pent-3-en-1-ols. The addition of tetrabutylammonium bromide (TBABr) to the biphasic system produces 1-substituted 2-methylbut-3-en-1-ols via usual γ-addition which is opposite to the α-addition without TBABr. The γ-addition to aromatic aldehydes exhibits anti-diastereoselectivity, while that to aliphatic aldehydes is not diastereoselective. The allylation of benzaldehyde by 1-chlorobut-2-ene in 1,3-dimethylimidazolidin-2-one (DMI) does not occur with tin(II) chloride or bromide but does proceed with tin(II) iodide and exhibits γ-syn selectivity which is unusual for a Barbier-type carbonyl allylation. In the carbonyl allylation by 1-chlorobut-2-ene with any tin(II) halide, the addition of tetrabutylammonium iodide (TBAI) accele...