Fathers' experiences of a vacuum extraction delivery - a qualitative study.

OBJECTIVE: To explore fathers' experiences of a birth by vacuum extraction (VE). METHOD: A qualitative interview study with 10 fathers analysed with qualitative content analysis. FINDINGS: The theme 'affected but helpless' refers to the father's role changing when childbirth terminates with a VE. From initially being involved in the delivery, his role switches to being merely an observer at the mercy of the professionals' knowledge and guidance. The VE procedure evoked concerns over the mother's and the child's safety and wellbeing, even if the fathers wanted the birth process to be over. The fathers considered the choice of conducting a VE as an adequate alternative, but they expressed concerns about consequences on future decisions. The theme encompasses all the main categories: wish to be involved, anxious observer, turbulent feelings and thoughts about consequences. CONCLUSIONS: VE delivery has a strong emotional impact on fathers and the procedure is often experienced as a dramatic way to end a birth and an ultimate way to terminate a long birth process. The results indicate that a lack of support and of a genuine opportunity to participate, as well as the mother's pain impair their experience, not the VE delivery, per se.

Quantum dynamical study of femtosecond photodesorption of CO from TiO2(110).

The photodesorption of CO from TiO2(110) by femtosecond pulses is investigated with the Surrogate Hamiltonian approach. The aim of the study is to resolve the relaxation mechanism and forecast the lifetime of the exited state based on a microscopic description of the excitation and relaxation processes. The parameters characterizing the system are obtained from ab initio and Density Functional Theory-calculations with one parameter estimated from physical considerations and convergence studies. Two electronic states are considered and the relaxation is assumed to be due to the interaction of the excited adsorbate with electron hole pairs in the surface. Desorption probabilities and velocity distributions of the desorbing molecules are calculated and an exited state lifetime is predicted. Throughout this paper atomic units, i.e., ℏ = me = e = a0 = 1, have been used unless otherwise stated.

Optimal control of open quantum systems: a combined surrogate hamiltonian optimal control theory approach applied to photochemistry on surfaces.

In this paper, control of open quantum systems with emphasis on the control of surface photochemical reactions is presented. A quantum system in a condensed phase undergoes strong dissipative processes. From a theoretical viewpoint, it is important to model such processes in a rigorous way. In this work, the description of open quantum systems is realized within the surrogate hamiltonian approach [R. Baer and R. Kosloff, J. Chem. Phys. 106, 8862 (1997)]. An efficient and accurate method to find control fields is optimal control theory (OCT) [W. Zhu, J. Botina, and H. Rabitz, J. Chem. Phys. 108, 1953 (1998); Y. Ohtsuki, G. Turinici, and H. Rabitz, J. Chem. Phys. 120, 5509 (2004)]. To gain control of open quantum systems, the surrogate hamiltonian approach and OCT, with time-dependent targets, are combined. Three open quantum systems are investigated by the combined method, a harmonic oscillator immersed in an ohmic bath, CO adsorbed on a platinum surface, and NO adsorbed on a nickel oxide surface. Throughout this paper, atomic units, i.e., ℏ = m(e) = e = a(0) = 1, have been used unless otherwise stated.

Optimal control of open quantum systems applied to the photochemistry of surfaces.

A quantum system in a condensed phase undergoes strong dissipative processes. The last decades have seen the rise of experimental and theoretical approaches for gaining control over dissipative phenomena. From a theoretical viewpoint it is important to model such processes in a rigorous way. An efficient and accurate method to find control fields is optimal control theory (OCT). In this Letter, a control scheme relying on OCT with time-dependent targets is employed to minimize dissipation, modeled within the surrogate Hamiltonian approach, on adsorbate-surface systems.