conclusions using the maximum dose depth from pdd curves and the inverse square law, the required ssdeff to calculate the dose distribution of the electron beam can be calculated. objectives the aim of this study was to determine the effective source-surface distance (ssdeff) of an electron linear accelerator (linac), and its dependence on energy and depth. materials and methods a varian linac ...

introduction: the present study evaluated the element distribution in completely set calcium-enriched mixture (cem) cement after application of 35% carbamide peroxide, 40% hydrogen peroxide and sodium perborate as commercial bleaching agents using an energy-dispersive x-ray microanalysis (edx) system. the surface structure was also observed using the scanning electron microscope (sem). methods ...

The modification of reaction centers from Rhodobacter sphaeroides by the introduction of pheophytins instead of bacteriopheophytins leads to interesting changes in the primary photosynthetic reaction: long-living populations of the excited electronic state of the special pair P* and the bacteriochlorophyll anion Bi show up. The data allow the determination of the energetics in the reaction cent...

The theoretical treatment of cycle-effects on total pi-electron energy, mainly elaborated by Nenad Trinajstic and his research group, is re-stated in a general and more formal manner. It enables to envisage several other possible ways of measuring the cycle-effects and points at further directions of research.

The vibronic coupling between P and R electronic states of a linear molecule is considered with the inclusion of the spin–orbit coupling of the P electronic state, employing the microscopic (Breit–Pauli) spin–orbit coupling operator in the single-electron approximation. The 6 · 6 Hamiltonian matrix in a diabatic spin-electronic basis is derived by an expansion of the molecular Hamiltonian in po...

Using the standard Hartree-Fock approximation on the basis of the random-phase approximation, we calculate the self-energy induced by exchange scattering due to electron-electron interaction in a spin-polarized two-dimensional electron gas 2DEG system. Applying the exchange self-energy to a Green’s function approach, we examine how the exchange interaction affects the spin-splitting in a 2DEG w...

An efficient dye sensitized solar cell (DSSC) is one possible solution to meet the world's rapidly increasing energy demands and associated climate challenges. This requires inexpensive and stable dyes with well-positioned frontier energy levels for maximal solar absorption, efficient charge separation, and high output voltage. Here we demonstrate an extensive computational screening of zinc po...