29 research outputs found
Multisymplectic Formalism for Cubic Horndeski Theories
We present the covariant multisymplectic formalism for the so-called cubic
Horndeski theories and discuss the geometrical and physical interpretation of
the constraints that arise in the unified Lagrangian-Hamiltonian approach. We
analyse in more detail the covariant Hamiltonian formalism of these theories
and we show that there are particular conditions that must be satisfied for the
Poincar\'e-Cartan form of the Lagrangian to project onto . From this
result, we study when a formulation using only multimomenta is possible. We
further discuss the implications of the general case, in which the projection
onto conditions are not met
Platinum Catalyzed Selective Hydration of Hindered Nitriles and Nitriles with Acid- or Base-Sensitive Groups.
Comparative Study of the Oil and Supercritical CO2 Extract of Mexican Pimento (Pimenta dioica Merrill)
The composition of the oil and volatile concentrate isolated from Mexican pimento berries (Pimenta dioica Merrill) was studied. The oil was obtained by steam distillation, by hydrodistillation and the volatile concentrate by supercritical carbon dioxide. The oil was analyzed by GC and by GC/MS. Twenty-five compounds were identified, including sabinene and methyl salicylate for the first time. Methyl eugenol (48.3-67.9%) was the main component of the oil