Activation of N2 on Manganese Nitride-Supported Ni3 and Fe3 Clusters and Relevance to Ammonia Formation.

Dual-site models were constructed to represent manganese nitride (Mn4N)-supported Ni3 and Fe3 clusters for NH3 synthesis. Density functional theory calculations produced an energy barrier of approximately 0.55 eV for N-N bond activation at the interfacial nitrogen vacancy sites (Nv); also, the hydrogenation and removal of interfacial N is promoted by earth-abundant Ni and Fe metals. Steady-state microkinetic modeling revealed that the turnover frequencies of NH3 production follow an order of Fe3@Mn4N ≈ Ni3@Mn4N > Mn4N > Fe ≫ Ni. Moreover, we present clear evidence that, before NH3 formation, NH migrates from Nv onto the metallic sites. Using N binding energy (BEN) and the transition-state energy of N2 activation (ETS) as descriptors, we concluded that the beneficial effects owing to interfacial Nv sites are the most pronounced when BEN is either too strong or too weak while ETS is high; otherwise, excessive Nv sites may hinder catalyst performance.

Investigating the effect of an empowerment program on physical activity of the elderly in Rezaeian Health Center, Iran, in 2014.

BACKGROUND: Reaching geriatric period is one of the greatest successes in human Beings. The older adults are predisposed to risk of many diseases and disabilities, and physical activity is one of the most efficient methods to prevent geriatric period disorders. Therefore, the present study aimed define the effect of an empowerment program on physical activity of the elderly residing in Shahid Rezaian health care center in 2014. MATERIALS AND METHODS: This quasi-experimental study was conducted on 70 older adults, age 65 years and over, selected through convenient sampling and assigned to groups of study and control. Study group was divided into 5 seven-member subgroups and a one-hour session of physical exercises was administrated for them once a week for eight sequential weeks. All subjects evaluated before and after intervention by International Physical Activity Questionnaire. Subjects' physical activity was scored, based on the personal activity protocol,and the results were compared. Significance level was considered as P<0.05. RESULTS: Frequency distributions of the female subjects were 29 (82%) and 28 (80%) in study and control groups respectively. Mean (SD) scores of physical activity were 347.8 (174.1) and 321.7 (119.2) before intervention, and 641.3 (240.6) and 331.3 (101.5) after intervention in study and control groups respectively. Independent t-test showed a significant increase in physical activity score in study group, compared to control (t=4.06, P<0.001). CONCLUSIONS: The level of physical activity can be improved in the elderly through application of an empowerment program so as to take steps toward solving their immobility related problems and promoting their health through application of an empowerment program at this period of their life.