4,375 research outputs found
Top-bottom mass hierarchy, puzzle and gauge coupling unification with split multiplets
A supersymmetric 5D SU(5) grand unification is considered. The SU(5) is
broken down to by the
assignment of the bulk field(s). The matter fields are located at the fixed
point(s). In the bulk, a Higgs multiplet (containing the bottom
doublet ) and the SU(5) gauge multiplet are located. At one fixed point,
(the top doublet) and the standard model matter multiplets are presented.
Because of the difference of the locations of and , one can obtain a
hierarchy between top and bottom Yukawa couplings. We also present a
possibility to understand the mass puzzle in this framework of the
split multiplet.Comment: LaTeX file of 17 pages including 3 eps figures. A note is added and
typo errors corrected. To appear in Euro. Phys. J.
Re-derivation of Young’s Equation, Wenzel Equation, and Cassie-Baxter Equation Based on Energy Minimization
Recently, Young’s equation, the Wenzel equation, and the Cassie-Baxter equation have been widely used with active research on superhydrophobic surfaces. However, experiments showed that the Wenzel equation and the Cassie-Baxter equation were not derived correctly. They should be reviewed on a firm physical ground. In this study, these equations are re-derived from a thermodynamic point of view by employing energy minimization and variational approach. The derivations provide a deeper understanding of these equations and the behavior of a contact angle. Also, in applying these equations, the limitations and considerations are discussed. It is expected that this study will provide a theoretical basis for the careful use of these equations on rough or chemically heterogeneous surfaces
Practical Design of Green Catalysts for PET Recycling and Energy Conversion
The recycling of chemicals and generation of alternative energy are central topics in the efforts toward sustainable development. Among these, research on plastics recycling and fuel cells has received significant attention, with the aim of designing novel catalysts to improve yield and efficiency. We highlight our work on these areas focusing on the chemical depolymerization of polyethylene terephthalate (PET) to recover its constituent monomer and the development of high-performance anode catalysts for polymer electrolyte membrane fuel cells (PEMFC). We demonstrate various flexible yet practical synthesis strategies (e.g. ultrasound-assisted deposition and biopolymer coating) that were used to obtain catalytic properties optimized for these applications. The effectiveness and simplicity of these methods render the catalysts to be truly green — from synthesis up to process application
125 GeV Higgs as a pseudo-Goldstone boson in supersymmetry with vector-like matters
We propose a possibility of the 125 GeV Higgs being a pseudo-Goldstone boson
in supersymmetry with extra vector-like fermions. Higgs mass is obtained from
loops of top quark and vector-like fermions from the global symmetry breaking
scale f at around TeV. The mu, Bmu/mu \sim f are generated from the dynamics of
global symmetry breaking and the Higgs quartic coupling vanishes at f as tan
beta \simeq 1. The relation of msoft \sim with f \sim mu \sim m_soft
\sim TeV is obtained and large mu does not cause a fine tuning for the
electroweak symmetry breaking. The Higgs to di-photon rate can be enhanced from
the loop of uncolored vector-like matters. The stability problem of Higgs
potential with vector-like fermions can be nicely cured by the UV completion
with the Goldstone picture.Comment: 28 pages, 8 figure
Structural and Thermal Stabilities of LixCoO2 cathode for LIB studied by a temperature programmed reduction (TPR).
In recent years, research and development of battery technology has primarily been focused on the lithium-ion batteries (LIB) due to the high specific energy density, and therefore are widely utilized as the energy source for portable electronics and electric vehicles. However, the battery safety is an essential issue to overcome, as the battery are required higher power density and larger capacity. Many efforts have been conducted to improve the safety of LIB in the active material processing, as well as the cell battery manufacturing and management technology
Optimal Design of a New Wheeled Mobile Robot by Kinetic Analysis for the Stair-Climbing States
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