259 research outputs found
Non-Minimal Two-Loop Inflation
We investigate the chaotic inflationary model using the two-loop effective
potential of a self-interacting scalar field theory in curved spacetime. We use
the potential which contains a non-minimal scalar curvature coupling and a
quartic scalar self-interaction. We analyze the Lyapunov stability of de Sitter
solution and show the stability bound. Calculating the inflationary parameters,
we systematically explore the spectral index and the tensor-to-scalar
ratio , with varying the four parameters, the scalar-curvature coupling
, the scalar quartic coupling , the renormalization scale
and the e-folding number . It is found that the two-loop correction on
is much larger than the leading-log correction, which has previously been
studied. We show that the model is consistent with the observation by Planck
with WMAP and a recent joint analysis of BICEP2.Comment: 11pages, 7figure
Brane Transitions from Exceptional Groups
It is a well-known result by Hanany and Witten that, when two five-branes
move across each other, D3-branes stretching between them are generated. Later
the same brane configurations played a crucial role in understanding the
worldvolume theory of multiple M2-branes. Recently the partition function of
multiple M2-branes was transformed to the Fredholm determinant for quantum
algebraic curves, where the characteristic 3/2 power law of degrees of freedom
is reproduced and the determinant enjoys a large symmetry given by exceptional
Weyl groups. The large exceptional Weyl group reproduces the Hanany-Witten
brane transitions and, besides, contains brane transitions unknown previously.
Aiming at understanding the new brane transitions better, we generalize our
previous study on the D5 quantum curve to the E7 case, which requires delicate
handling of degeneracies. By combining the results of these two cases, we
propose a "local" rule for the brane transitions.Comment: 33 pages, 8 eps figures; clarifications adde
Effect of hydraulic conditions on manganese accumulation by physical and chemical pathways in chlorinated water distribution system: A preliminary laboratory study
The accumulation of manganese (Mn) in drinking water distribution systems (DWDS) is the main reason for ‘black water’ occurrences at customers' taps. Here, we focused on the impact of hydraulic conditions on Mn accumulation in well chlorinated DWDS, particularly on the physical pathway (i.e., the attachment of particulate Mn to the inner pipe surface) and the chemical pathway (i.e., the autocatalytic oxidation of Mn2+ on the surface of accumulated Mn). Mn accumulation on epoxy resin, a typical lining material for distribution pipes in Japan, was observed in laboratory-scale experiments under different water velocity conditions. The results showed that Mn accumulation was significantly enhanced under higher velocity conditions, which was then fitted with the numerical models describing Mn accumulation by the physical and chemical pathways and the detachment. The rate constants for the physical and chemical pathways had a positive relationship with the flow turbulence in the investigated range, suggesting that hydraulic conditions in DWDS play an important role in Mn accumulation. Effects of Mn speciation and water characteristics on the accumulation process were also simulated under various hydraulic conditions. Based on the obtained results, appropriate countermeasures to control manganese accumulation were then discussed
Interleukin 18 Acts on Memory T Helper Cells Type 1 to Induce Airway Inflammation and Hyperresponsiveness in a Naive Host Mouse
Interleukin (IL)-18 was originally regarded to induce T helper cell (Th)1-related cytokines. In general, factors favoring interferon (IFN)-γ production are believed to abolish allergic diseases. Thus, we tested the role of IL-18 in regulation of bronchial asthma. To avoid a background response of host-derived T cells, we administered memory type Th1 or Th2 cells into unsensitized mice and examined their role in induction of bronchial asthma. Administration of antigen (Ag) induced both airway inflammation and airway hyperresponsiveness (AHR) in mice receiving memory Th2 cells. In contrast, the same treatment induced only airway inflammation but not AHR in mice receiving memory Th1 cells. However, these mice developed striking AHR when they were coadministered with IL-18. Furthermore, mice having received IFN-γ–expressing Th1 cells sorted from polarized Th1 cells developed severe airway inflammation and AHR after intranasal administration of Ag and IL-18. Thus, Th1 cells become harmful when they are stimulated with Ag and IL-18. Newly polarized Th1 cells and IFN-γ–expressing Th1 cells, both of which express IL-18 receptor α chain strongly, produce IFN-γ, IL-9, IL-13, granulocyte/macrophage colony-stimulating factor, tumor necrosis factor α, regulated on activation, normal T cell expressed and secreted, and macrophage inflammatory protein 1α upon stimulation with Ag, IL-2, and IL-18 in vitro. Thus, Ag and IL-18 stimulate memory Th1 cells to induce severe airway inflammation and AHR in the naive host
Video-Assisted Thoracoscopic Surgery Using Extracorporeal Membrane Oxygenation for Intractable Pneumothorax
Intractable pneumothorax with poor lung function that has received multiple conservative treatments may occur. Case 1 was a 70-year-old woman with aspergilloma who was admitted for pneumothorax. Case 2 was a 68-year-old man with acute exacerbation of interstitial pneumonia who developed pneumothorax. In both cases, multiple conservative therapies were administered, but the leak continued; thus, operations using veno-venous extracorporeal membrane oxygenation (ECMO) were planned. By video-assisted thoracoscopic surgery (VATS), we obtained the optimal surgical field by lung collapse. We removed many blood clots that were used for pleurodesis, ligated the bulla in case 1, and covered the leak point with strengthening agents in case 2. For cases of intractable pneumothorax, lung collapse by ECMO is advantageous because we can check details and leak points even in blood clots or in poor condition of the lung, and we can maneuver the lung in poor condition with a clear surgical field
Study on Wash-out of Asphalt Mixture Caused by Repeated Heating and Cooling Immersion Test
Stripping generates within the asphalt pavements due to continuous effect of moisture has been one of the concerns by the road authorities worldwide. Without a proper treatment, it could cause potholes and lower the bearing capacity of asphalt pavements. With regard to this, it is well known that the bipolar anti-stripping agent is effective to prevent the stripping due to its electrochemical bonding characteristics between aggregate and asphalt. Wash-out is a dynamic water action that could strip the asphalt mortar from pavement surfacing. Such distress spotted on many roads, whereby, granite aggregates are normally used as the main material in asphalt mixtures. In this study, the experimental work is focused on stripping phenomenon caused by multiple moisture conditioning cycles at 80 °C, and a newly developed evaluation protocol using a Repeated Heating and Cooling Immersion test is adopt-ed. The Wash-out, which is closely associated with stripping, is studied to evaluate the resistance of asphalt pavement against moisture damage. This study is a laboratory scale evaluation and the phenomenon in the field is not yet adequately considered. The repeated heating and cooling immersion procedure is an accelerated strip-ping conditioning without applying an external force. It is clarified that the resistance to the Wash-out of asphalt mixture is improved with the presence of the bi-polar anti-stripping agent, known as Tough Fix Hyper at the rate of 0.15% or more
Study on Wash-out of Asphalt Mixture Caused by Repeated Heating and Cooling Immersion Test
Stripping generates within the asphalt pavements due to continuous effect of moisture has been one of the concerns by the road authorities worldwide. Without a proper treatment, it could cause potholes and lower the bearing capacity of asphalt pavements. With regard to this, it is well known that the bipolar anti-stripping agent is effective to prevent the stripping due to its electrochemical bonding characteristics between aggregate and asphalt. Wash-out is a dynamic water action that could strip the asphalt mortar from pavement surfacing. Such distress spotted on many roads, whereby, granite aggregates are normally used as the main material in asphalt mixtures. In this study, the experimental work is focused on stripping phenomenon caused by multiple moisture conditioning cycles at 80 °C, and a newly developed evaluation protocol using a Repeated Heating and Cooling Immersion test is adopt-ed. The Wash-out, which is closely associated with stripping, is studied to evaluate the resistance of asphalt pavement against moisture damage. This study is a laboratory scale evaluation and the phenomenon in the field is not yet adequately considered. The repeated heating and cooling immersion procedure is an accelerated strip-ping conditioning without applying an external force. It is clarified that the resistance to the Wash-out of asphalt mixture is improved with the presence of the bi-polar anti-stripping agent, known as Tough Fix Hyper at the rate of 0.15% or more
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