12 research outputs found
Reaksi Hidrogenasi Metoksida Menjadi Metanol pada Klaster Pd6Ni
Kami melakukan kajian teoretis mengenai reaksi hidrogenasi metoksida (H3CO) menjadi metanol (CH3OH) pada katalis klaster Pd6Ni secara teoretis menggunakan perhitungan berbasis teori fungsional kerapatan (DFT). Reaksi ini merupakan salah satu reaksi pembatas laju pada proses konversi gas karbon dioksida (CO2) menjadi metanol. Hasil perhitungan kami menunjukkan bahwa reaksi hidrogenasi metoksida pada katalis klaster Pd6Ni memiliki energi aktivasi yang lebih baik dibandingkan dengan energi aktivasi pada katalis konvensional berbasis permukaan Cu. Hal ini disebabkan karena klaster Pd6Ni mampu menstabilkan adsorpsi molekul metanol dengan baik dan memiliki energi adsorpsi *H yang relatif lemah
Local and global existence of solutions to scalar equations on spatially flat universe as a background with non-minimal coupling
We prove the wellposedness of scalar wave equations on spatially at universe as a background with nonminimal coupling with the scalar potential turned on by introducing the k-order linear energy and the corresponding energy norm. In the local case, we show that both the k-order linear energy and the energy norm are bounded for finite time with initial data in Hk+1 x Hk. Whereas in the global case, we have to add three assumptions related to the nonminimal coupling constant, the scale factor of spacetimes, and the form of the scalar potential that has to be a polynomial with a small positive parameter. Then, we show that the solution does globally exist with a particular decay estimate that depends on the scale factor of the spacetimes. Finally, we provide some physical models that support our general setup
Some Aspects of Spherical Symmetric Extremal Dyonic Black Holes in 4d N=1 Supergravity
In this paper we study several aspects of extremal spherical symmetric black
hole solutions of four dimensional N=1 supergravity coupled to vector and
chiral multiplets with the scalar potential turned on. In the asymptotic region
the complex scalars are fixed and regular which can be viewed as the critical
points of the black hole and the scalar potentials with vanishing scalar
charges. It follows that the asymptotic geometries are of a constant and
non-zero scalar curvature which are generally not Einstein. These spaces could
also correspond to the near horizon geometries which are the product spaces of
a two anti-de Sitter surface and the two sphere if the value of the scalars in
both regions coincides. In addition, we prove the local existence of
non-trivial radius dependent complex scalar fields which interpolate between
the horizon and the asymptotic region. We finally give some simple
{\lC}^{n}-models with both linear superpotential and gauge couplings.Comment: 17 pages, no figure. Added an author. Major revision: typos and
grammar corrected, some statements modified, added a section about local
existence of scalar fields. Accepted for publication in Int J Mod Phys