Calculation Of Pressure Rise And Energy Of Hot Gases Due To High Energy Arcing Faults In The Metal-clad Switchgear

This paper presents the 3-D CFD calculation results of the pressure rise due to the High Energy Arcing Faults (HEAFs) in the metal-clad switchgears. The calculations were performed considering the came-off of the roof panel that was observed in the arc tests. The calculated pressure development approximately agreed with the measured one. Furthermore, the energy of hot gases exhausted from the broken roof panel was calculated to investigate the thermal effect of hot gases

Analytical investigation of magnetic field distributions around superconducting strips on ferromagnetic substrates

The complex-field approach is developed to derive analytical expressions of the magnetic field distributions around superconducting strips on ferromagnetic substrates (SC/FM strips). We consider the ferromagnetic substrates as ideal soft magnets with an infinite magnetic permeability, neglecting the ferromagnetic hysteresis. On the basis of the critical state model for a superconducting strip, the ac susceptibility $\chi_1'+i\chi_1''$ of a SC/FM strip exposed to a perpendicular ac magnetic field is theoretically investigated, and the results are compared with those for superconducting strips on nonmagnetic substrates (SC/NM strips). The real part $\chi_1'$ for $H_0/j_cd_s\to 0$ (where $H_0$ is the amplitude of the ac magnetic field, $j_c$ is the critical current density, and $d_s$ is the thickness of the superconducting strip) of a SC/FM strip is 3/4 of that of a SC/NM strip. The imaginary part $\chi_1''$ (or ac loss $Q$) for $H_0/j_cd_s<0.14$ of a SC/FM strip is larger than that of a SC/NM strip, even when the ferromagnetic hysteresis is neglected, and this enhancement of $\chi_1''$ (or $Q$) is due to the edge effect of the ferromagnetic substrate.Comment: 8 pages, 6 figures, submitted to Phys. Rev.

Protein processing characterized by a gel-free proteomics approach

We describe a method for the specific isolation of representative N-terminal peptides of proteins and their proteolytic fragments. Their isolation is based on a gel-free, peptidecentric proteomics approach using the principle of diagonal chromatography. We will indicate that the introduction of an altered chemical property to internal peptides holding a free α-N-terminus results in altered column retention of these peptides, thereby enabling the isolation and further characterization by mass spectrometry of N-terminal peptides. Besides pointing to changes in protein expression levels when performing such proteome surveys in a differential modus, protease specificity and substrate repertoires can be allocated since both are specified by neo-N-termini generated after a protease cleavage event. As such, our gel-free proteomics technology is widely applicable and amenable for a variety of proteome-driven protease degradomics research

High basal STAT4 balanced by STAT1 induction to control type 1 interferon effects in natural killer cells

The best-characterized type 1 interferon (IFN) signaling pathway depends on signal transducer and activator of transcription 1 (STAT1) and STAT2. The cytokines can, however, conditionally activate all STATs. Regulation of their access to particular signaling pathways is poorly understood. STAT4 is important for IFN-γ induction, and NK cells are major producers of this cytokine. We report that NK cells have high basal STAT4 levels and sensitivity to type 1 IFN–mediated STAT4 activation for IFN-γ production. Increases in STAT1, driven during viral infection by either type 1 IFN or IFN-γ, are associated with decreased STAT4 access. Both STAT1 and STAT2 are important for antiviral defense, but STAT1 has a unique role in protecting against sustained NK cell IFN-γ production and resulting disease. The regulation occurs with an NK cell type 1 IFN receptor switch from a STAT4 to a STAT1 association. Thus, a fundamental characteristic of NK cells is high STAT4 bound to the type 1 IFN receptor. The conditions of infection result in STAT1 induction with displacement of STAT4. These studies elucidate the critical role of STAT4 levels in predisposing selection of specific signaling pathways, define the biological importance of regulation within particular cell lineages, and provide mechanistic insights for how this is accomplished in vivo

Jmjd2/Kdm4 demethylases are required for expression of Il3ra and survival of acute myeloid leukemia cells

Acute myeloid leukemias (AMLs) with a rearrangement of the mixed-linage leukemia (MLL) gene are aggressive hematopoietic malignancies. Here, we explored the feasibility of using the H3K9- and H3K36-specific demethylases Jmjd2/Kdm4 as putative drug targets in MLL-AF9 translocated leukemia. Using Jmjd2a, Jmjd2b, and Jmjd2c conditional triple-knockout mice, we show that Jmjd2/Kdm4 activities are required for MLL-AF9 translocated AML in vivo and in vitro. We demonstrate that expression of the interleukin 3 receptor a (Il3ra also known as Cd123) subunit is dependent on Jmjd2/Kdm4 through a mechanism involving removal of H3K9me3 from the promoter of the Il3ra gene. Importantly, ectopic expression of Il3ra in Jmjd2/Kdm4 knockout cells alleviates the requirement of Jmjd2/Kdm4 for the survival of AML cells, showing that Il3ra is a critical downstream target of Jmjd2/Kdm4 in leukemia. These results suggest that the JMJD2/KDM4 proteins are promising drug targets for the treatment of AML

Low-Rank Decompositions of Three-Nucleon Forces via Randomized Projections

Ab initio calculations for nuclei and nuclear matter are limited by the computational requirements of processing large data objects. In this work, we develop low-rank singular value decompositions for chiral three-nucleon interactions, which dominate these limitations. In order to handle the large dimensions in representing three-body operators, we use randomized decomposition techniques. We study in detail the sensitivity of different three-nucleon topologies to low-rank matrix factorizations. The developed low-rank three-nucleon interactions are benchmarked in Faddeev calculations of the triton and ab initio calculations of medium-mass nuclei. Exploiting low-rank properties of nuclear interactions will be particularly important for the extension of ab initio studies to heavier and deformed systems, where storage requirements will exceed the computational capacities of the most advanced high-performance-computing facilities.Comment: 7 pages, 4 figure