34,748 research outputs found
A Hydro Wheel System in A Non-Natural Pond Using Renewable
One of the most cost-effective ways to generate electricity is through waterwheels. Because of the need for clean energy and sustainable electricity production, hydropower currently plays an important role in meeting energy demand. Although water wheels were studied academically as early as the eighteenth century, they were mostly ignored until the twentieth century. Only in the last two decades has there been a revived interest in their use among scientists. The researcher came up with this topic to discuss its benefits and how it will be beneficial in our daily lives and make our surroundings safe, which needs enough light and helps the school or park premises lighten up the dark areas at night. Having enough illumination inside the premises of in schools and parks, according to numerous sources and data gathering findings, will help folks become comfortable in the location they are staying or visiting. Good illumination can help with mobility, safety, and security
Persistence of transition state structure in chemical reactions driven by fields oscillating in time
Chemical reactions subjected to time-varying external forces cannot generally
be described through a fixed bottleneck near the transition state barrier or
dividing surface. A naive dividing surface attached to the instantaneous, but
moving, barrier top also fails to be recrossing-free. We construct a moving
dividing surface in phase space over a transition state trajectory. This
surface is recrossing-free for both Hamiltonian and dissipative dynamics. This
is confirmed even for strongly anharmonic barriers using simulation. The power
of transition state theory is thereby applicable to chemical reactions and
other activated processes even when the bottlenecks are time-dependent and move
across space
Chemical reactions induced by oscillating external fields in weak thermal environments
Chemical reaction rates must increasingly be determined in systems that
evolve under the control of external stimuli. In these systems, when a reactant
population is induced to cross an energy barrier through forcing from a
temporally varying external field, the transition state that the reaction must
pass through during the transformation from reactant to product is no longer a
fixed geometric structure, but is instead time-dependent. For a periodically
forced model reaction, we develop a recrossing-free dividing surface that is
attached to a transition state trajectory [T. Bartsch, R. Hernandez, and T.
Uzer, Phys. Rev. Lett. 95, 058301 (2005)]. We have previously shown that for
single-mode sinusoidal driving, the stability of the time-varying transition
state directly determines the reaction rate [G. T. Craven, T. Bartsch, and R.
Hernandez, J. Chem. Phys. 141, 041106 (2014)]. Here, we extend our previous
work to the case of multi-mode driving waveforms. Excellent agreement is
observed between the rates predicted by stability analysis and rates obtained
through numerical calculation of the reactive flux. We also show that the
optimal dividing surface and the resulting reaction rate for a reactive system
driven by weak thermal noise can be approximated well using the transition
state geometry of the underlying deterministic system. This agreement persists
as long as the thermal driving strength is less than the order of that of the
periodic driving. The power of this result is its simplicity. The surprising
accuracy of the time-dependent noise-free geometry for obtaining transition
state theory rates in chemical reactions driven by periodic fields reveals the
dynamics without requiring the cost of brute-force calculations
Are CP Violating Effects in the Standard Model Really Tiny?
We derive an effective action of the bosonic sector of the Standard Model by
integrating out the fermionic degrees of freedom in the worldline approach. The
CP violation due to the complex phase in the CKM matrix gives rise to
CP-violating operators in the effective action. We calculate the prefactor of
the appropriate next-to-leading order operators and give general estimates of
CP violation in the bosonic sector of the Standard Model. In particular, we
show that the effective CP violation for weak gauge fields is not suppressed by
the Yukawa couplings of the light quarks and is much larger than the bound
given by the Jarlskog determinant.Comment: 4 pages. To appear in the proceedings of the 8th Conference on Strong
and Electroweak Matter (SEWM08), Amsterdam, the Netherlands, 26-29 August
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