Diffusive and rotational dynamics of condensed n-H2 confined in MCM-41.

In this paper, we report an inelastic neutron scattering study of liquid and solid n-H2 confined within MCM-41. This is a high surface area, mesoporous silica glass with a narrow pore size distribution centered at 3.5 nm. The scattering data provides information about the diffusive and rotational dynamics of the adsorbed n-H2 at low temperatures. In the liquid state, the neutron scattering data demonstrates that only a fraction of the adsorbed o-H2 is mobile on the picosecond time scale. This mobile fraction undergoes liquid-like jump diffusion, and values for the residence time τ and effective mean-squared displacement 〈u(2)〉 are reported as a function of pore filling. In the solid state, the rotational energy levels of adsorbed H2 are strongly perturbed from their free quantum rotor behavior in the bulk solid. The underlying orientational potential of the hindered rotors is due to the surface roughness and heterogeneity of the MCM-41 pore walls. This potential is compared to the hindering potential of other porous silicas, such as Vycor. Strong selective adsorption makes the interfacial layer rich in o-H2, leaving the inner core volume consisting of a depleted mixture of o-H2 and p-H2.

A comprehensive approach to clinical evaluation.

Historically, the summative clinical evaluation of nursing students has been problematic. Tools of measurement for clinical performance have been subjective and, at times, biased at several levels. With these thoughts and past experiences in mind, the faculty in an associate degree nursing program developed a comprehensive approach to summative clinical evaluation. The process began with the development and implementation of a Clinical Performance Manual (CPM) describing five components of the summative evaluation process. These included the: ability to consistently exhibit professional behaviors; random skills performance examination; plan of care examination; critical situations examination; and required course assignments. These components were developed with the intent of objectifying the measurement of cognitive, affective, and psychomotor skills of students. After 1 year of implementing this process with 250 students, feedback received from faculty and students was reviewed and discussed. Reliability and validity studies have been conducted. A decision was made to continue with this new method of evaluation. Recommendations include piloting and implementing the process in others schools and programs.