89 research outputs found
Dilaton in Two-Time Physics as trigger of electroweak phase transition and inflation
Within the SP(2, R) symmetry, the Two-time model (2T model) has six dimension
with two time dimensions. The model has a dilaton particle that makes the
symmetry breaking differently from the Standard Model. By reducing the 2T
metric to the Minkowski one (1T metric), we consider the electroweak phase
transition picture in the 2T model with the dilaton as the trigger. Our
analysis shows that Electro-weak Phase Transition (EWPT) is a first-order phase
transition at the GeV scale, its strength is about and the
mass of dilaton is in interval GeV. Furthermore, the metric of 2T
model can be reduced to the Randall-Sundrum model, so the dilaton acts as
inflaton with the slow-roll approximation. Therefore the 2T-model indirectly
suggests that extra-dimension can be also a source of EWPT and inflation. The
EWPT problem can be used to determine scale parameters that refer to
relationships between two metrics.Comment: 25 pages, 2 figure
Properties of Concrete Containing Rubber Aggregate Derived From Discarded Tires
This study carried out the experiment to evaluate the effects of different contents and sizes of rubber particles derived from discarded tires used for replacing fine and coarse natural aggregates, on the workability of fresh rubberized concrete and the compressive and flexural strengths of hardened rubberized concrete. The study results showed that the workability of fresh rubberized concrete was improved when replacing natural fine aggregate (sand) with fine rubber particles (2.5-5 mm) at the replacing proportions of 30-50% by volume, and when replacing natural coarse aggregate (crushed stone) with coarse rubber particles (5-20 mm) at the replacing proportions of 10-30% by volume. With respect to the mechanical properties of hardened rubberized concrete, a larger reduction in the compressive and flexural strengths was generally found when the replacing proportions increased and when coarse aggregate rather than fine aggregate was replaced by rubber particles at all replacing proportions (10-50%). However, the study results also indicated that using fine rubber particles for replacing fine natural aggregate at the low replacing proportion (up to 10%) might not cause the significant effect on the compressive and flexural strength of rubberized concrete
Miliutine A acid, a new cyclofarnesane sesquiterpene from the stems of <i>Miliusa velutina</i>
Six compounds were isolated from the ethyl acetate extract of the stems of Miliusa velutina, including miliutine A acid (1), a new cyclofarnesane sesquiterpenoid; miliutine B methyl ester (2), a cyclofarnesane sesquiterpenoid which was determined the absolute configuration for the first time and four known phenol derivatives (3–6). NMR spectroscopic and mass spectrometry were used for identifying relative configurations. The assignments of the absolute configurations were determined based on Electronic Circular Dichroism (ECD) and NOESY spectra analysis. All six compounds were screened for their in vitro cytotoxic activities against HepG2 cell line using the SRB assay and they showed weak or none activities.</p
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