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Materials Data on LaHO by Materials Project

LaHO is Fluorite-derived structured and crystallizes in the tetragonal P4/nmm space group. The structure is three-dimensional. there are three inequivalent La3+ sites. In the first La3+ site, La3+ is bonded in a body-centered cubic geometry to four equivalent H1- and four equivalent O2- atoms. All La–H bond lengths are 2.50 Å. All La–O bond lengths are 2.45 Å. In the second La3+ site, La3+ is bonded in a distorted body-centered cubic geometry to four equivalent H1- and four equivalent O2- atoms. All La–H bond lengths are 2.54 Å. All La–O bond lengths are 2.43 Å. In the third La3+ site, La3+ is bonded in a body-centered cubic geometry to four equivalent H1- and four equivalent O2- atoms. All La–H bond lengths are 2.58 Å. All La–O bond lengths are 2.41 Å. H1- is bonded to four La3+ atoms to form HLa4 tetrahedra that share corners with eight equivalent HLa4 tetrahedra, corners with eight equivalent OLa4 tetrahedra, edges with two equivalent HLa4 tetrahedra, and edges with four equivalent OLa4 tetrahedra. O2- is bonded to four La3+ atoms to form OLa4 tetrahedra that share corners with eight equivalent HLa4 tetrahedra, corners with eight equivalent OLa4 tetrahedra, edges with two equivalent OLa4 tetrahedra, and edges with four equivalent HLa4 tetrahedra.

36 MATERIALS SCIENCE↗

Closed-loop, pilot/vehicle analysis of the approach and landing task

In the case of approach and landing, it is universally accepted that the pilot uses more than one vehicle response, or output, to close his control loops. Therefore, to model this task, a multi-loop analysis technique is required. The analysis problem has been in obtaining reasonable analytic estimates of the describing functions representing the pilot's loop compensation. Once these pilot describing functions are obtained, appropriate performance and workload metrics must then be developed for the landing task. The optimal control approach provides a powerful technique for obtaining the necessary describing functions, once the appropriate task objective is defined in terms of a quadratic objective function. An approach is presented through the use of a simple, reasonable objective function and model-based metrics to evaluate loop performance and pilot workload. The results of an analysis of the LAHOS (Landing and Approach of Higher Order Systems) study performed by R.E. Smith is also presented.

Anderson, M. R.↗