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A semi-analytic method for quickly approximating the density-reduced critical electric field for arbitrary mixtures of gases is proposed and validated. Determination of this critical electric field is crucial for designing and testing alternatives to SF$_6$ for insulating high voltage electrical equipment. We outline the theoretical basis of the approximation formula from electron fluid conservation equations, and demonstrate how for binary mixtures the critical electric field can be computed from the transport data of electrons in the pure gases. We demonstrate validity of the method in mixtures of N$_2$ and O$_2$, and SF$_6$ and O$_2$. We conclude with an application of the method to approximate the critical electric field for mixtures of SF$_6$ and HFO1234ze(E), which is a high interest mixture being actively studied for high voltage insulation applications.

The theory for electron transport in simple liquids developed by Cohen and Lekner is extended to simple liquid mixtures. The focus is on developing benchmark models for binary mixtures of hard-spheres, using the Percus-Yevick model to represent the density structure effects. A multi-term solution of the Boltzmann equation is employed to investigate the effect of the binary mixture structure on hard-sphere electron scattering cross-sections and transport properties, including the drift velocity, mean energy, longitudinal and transverse diffusion coefficients. Benchmark calculations are established for electrons driven out of equilibrium by a range of reduced electric field strengths 0.1-100 Td., Comment: 13 pages, 6 figures, 2 tables. To be published in J. Phys. B

Ab-initio electron - liquid phase xenon fully differential cross-sections for electrons scattering in liquid xenon are developed from a solution of the Dirac-Fock scattering equations, using a recently developed framework [1] which considers multipole polarizabilities, a non-local treatment of exchange, and screening and coherent scattering effects. A multi-term solution of Boltzmann's equation accounting for the full anisotropic nature of the differential cross-section is used to calculate transport properties of excess electrons in liquid xenon. The results were found to agree to within 25% of the measured mobilities and characteristic energies over the reduced field range of 10^{-4} to 1 Td. The accuracies are comparable to those achieved in the gas phase. A simple model, informed by highly accurate gas-phase cross-sections, is presented to transform highly accurate gas-phase cross-sections to improve the liquid cross-sections, which was found to enhance the accuracy of the transport coefficient calculations., Comment: 26 pages, 9 figures. arXiv admin note: text overlap with arXiv:1503.00377

Attempts at being polite can fail through unwitting violation of speech act rules (SARs). Several situations illustrate the use of "please" by Japanese users of English. The question of whose SARs should apply in intercultural communication in English is addressed. (Contains 13 references.) (Author)

Through a review of recent studies on the subject, it becomes clear that the focus of innovation in language teaching has been largely concerned with technological change rather than adoption of new pedagogical procedures. Furthermore, the assumptions behind innovation efforts need to be challenged to determine whose interests are being served. (52 references) (LET)

A college writing teacher relates his experiences in teaching writing to a group of Japanese undergraduates with a process-oriented curriculum. The narrative and analysis are based on the teacher's journal record of the 10-week course. The narrative focuses on the investigation of the curriculum's implementation, the teacher's reaction to the use of techniques used with other students and advocated to other teachers, and student behavior and achievement outcomes. The report describes the students' characteristics, the teachers teaching the course, and the specific aims, methods, and procedures used in classroom presentation. The author's journal entries, written responses to student writing, and some writing samples are included and expanded. Student evaluations of the course are also presented. Personal, pedagogic, and academic lessons learned from the experience are discussed briefly. (MSE)

BACKGROUND: Although abnormal L-arginine NO signaling contributes to endothelial dysfunction in the aging cardiovascular system, the biochemical mechanisms remain controversial. L-arginine, the NO synthase (NOS) precursor, is also a substrate for arginase. We tested the hypotheses that arginase reciprocally regulates NOS by modulating L-arginine bioavailability and that arginase is upregulated in aging vasculature, contributing to depressed endothelial function. METHODS AND RESULTS: Inhibition of arginase with (S)-(2-boronoethyl)-L-cysteine, HCl (BEC) produced vasodilation in aortic rings from young (Y) adult rats (maximum effect, 46.4+/-9.4% at 10(-5) mol/L, P<0.01). Similar vasorelaxation was elicited with the additional arginase inhibitors N-hydroxy-nor-L-arginine (nor-NOHA) and difluoromethylornithine (DFMO). This effect required intact endothelium and was prevented by 1H-oxadiazole quinoxalin-1-one (P<0.05 and P<0.001, respectively), a soluble guanylyl cyclase inhibitor. DFMO-elicited vasodilation was greater in old (O) compared with Y rat aortic rings (60+/-6% versus 39+/-6%, P<0.05). In addition, BEC restored depressed L-arginine (10(-4) mol/L)-dependent vasorelaxant responses in O rings to those of Y. Arginase activity and expression were increased in O rings, whereas NOS activity and cyclic GMP levels were decreased. BEC and DFMO suppressed arginase activity and restored NOS activity and cyclic GMP levels in O vessels to those of Y. CONCLUSIONS: These findings demonstrate that arginase modulates NOS activity, likely by regulating intracellular L-arginine availability. Arginase upregulation contributes to endothelial dysfunction of aging and may therefore be a therapeutic target.