3,892 research outputs found
Symmetry Nonrestoration at High Temperature in Little Higgs Models
A detailed study of the high temperature dynamics of the scalar sector of
Little Higgs scenarios, proposed to stabilize the electroweak scale, shows that
the electroweak gauge symmetry remains broken even at temperatures much larger
than the electroweak scale. Although we give explicit results for a particular
modification of the Littlest Higgs model, we expect that the main features are
generic. As a spin-off, we introduce a novel way of dealing with scalar
fluctuations in nonlinear sigma models, which might be of interest for
phenomenological applications.Comment: 23 pages, LaTeX, 4 figure
New results on bare-tether current
Recent results on the validity of the orbital-motion-limited (OML) regime of cylindrical Langmuir probes, which are essential for bare-tether applications, are extended to show how the current lags behind the OML value beyond the OML regime, and the possible effects of motion of the probe relative to the plasma
Collection effects on close pararell bare tethers
We review previously published results, and present new results, on the way current to a cylindrical probe drops below the orbital-motion-limited (OML) value for probe cross-sections too large or concave. Results on size and shape effects arise from unrelated behavior in the near and far potential field, and apply to a general cross-section,
which can be characterised by radius Req and perimeter peij of equivalent circles. These results are used to discuss collection interference among two or more parallel bare tethers when brought from far away to contact
Characterization of Changes in Gluten Proteins in Low-Gliadin Transgenic Wheat Lines in Response to Application of Different Nitrogen Regimes
Gluten proteins are major determinants of the bread making quality of wheat but also of important gluten-related disorders. The gluten protein accumulation during grain filling is strongly influenced by nitrogen fertilization. We have characterized the gluten proteins in low-gliadin wheat lines as influenced by nitrogen treatments in two experiments. These transgenic lines, D783, D793, C655, D577, and E82 were obtained by using two different RNAi silencing fragments and two endosperm-specific promoters to drive the silencing fragments (d-hordein and Îł-gliadin). In Experiment 1, we used three nitrogen fertilizer rates (120, 360, and 1080 mg N) added at sowing stage and combined with two sulfur rates (8 and 30 mg S); Experiment 2 included two nitrogen levels (120 and 1080 mg N), which were added according to the greatest demand per plant using split applications. The protein quantification was accomplished by Reverse-Phase High-Performance Liquid Chromatography and gluten content (ppm) determined using monoclonal antibody R5 (Competitive R5 ELISA). The results showed differences in protein accumulation between the two transgenic lines with the same silencing fragment but different promoter. Lines D793 and E82 showed low gliadin and an increment in glutenin content with increasing nitrogen. Competitive ELISA R5 showed a significant decrease in gluten content using split applications of nitrogen (Experiment 2) with 120 mg N compared to Experiment 1. In addition, line E82 ensures that variations in N fertilization will not result in increased gluten content.The Spanish Ministry of Economy and Competitiveness (Projects AGL2013-48946-C3-1-R and AGL2016-80566-P), the European Regional Development Fund (FEDER) and Junta de AndalucĂa (Project P11-AGR-7920) supported this work.Peer Reviewe
Magnetic self-field effects on bare-tether current collection
It has been recently suggested that the magnetic field
created by the current in a bare tether could sensibly
reduce its electron collection capability in the magnetised ionosphere, a region of closed magnetic surfaces disconnecting the cylinder from infinity. In this paper, the ohmic voltage drop along the tether is taken into account in considering self-field effects. Separate analyses are carried out for the thrust and power generation and drag modes of operation, which are affected in different ways. In the power generation and drag modes, bias decreases as current increases along the tether, starting at the anodic, positively-biased end (upper end in the usual, eastward-flying spacecraft); in the thrust mode of operation, bias increases as current increases along the tether, starting at the lower end. When the ohmic voltage drop is considered, self-field effects are shown to be weak, in all cases, for tape tethers, and for circular cross-section tethers just conductive in a thin outer layer. Self-field effects might become important, in the drag case only, for tethers with fully conductive cross sections that are unrealistically heavy
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