Towards linking lab and field lifetimes of perovskite solar cells.

Metal halide perovskite solar cells (PSCs) represent a promising low-cost thin-film photovoltaic technology, with unprecedented power conversion efficiencies obtained for both single-junction and tandem applications1-8. To push PSCs towards commercialization, it is critical, albeit challenging, to understand device reliability under real-world outdoor conditions where multiple stress factors (for example, light, heat and humidity) coexist, generating complicated degradation behaviours9-13. To quickly guide PSC development, it is necessary to identify accelerated indoor testing protocols that can correlate specific stressors with observed degradation modes in fielded devices. Here we use a state-of-the-art positive-intrinsic-negative (p-i-n) PSC stack (with power conversion efficiencies of up to approximately 25.5%) to show that indoor accelerated stability tests can predict our six-month outdoor ageing tests. Device degradation rates under illumination and at elevated temperatures are most instructive for understanding outdoor device reliability. We also find that the indium tin oxide/self-assembled monolayer-based hole transport layer/perovskite interface most strongly affects our device operation stability. Improving the ion-blocking properties of the self-assembled monolayer hole transport layer increases averaged device operational stability at 50 °C-85 °C by a factor of about 2.8, reaching over 1,000 h at 85 °C and to near 8,200 h at 50 °C, with a projected 20% degradation, which is among the best to date for high-efficiency p-i-n PSCs14-17.

Rationale and development of the Move More North Carolina: Recommended Standards for After-School Physical Activity.

The purpose of this article is to describe the rationale and procedure employed in developing the Move More North Carolina: Recommended Standards for After-School Physical Activity, which was publicly released statewide in April 2009. The Standards outline evidenced-based best practices for after-school programs to implement in order to increase amount and quality of physical activity (PA) among program participants. The Standards can be applied in any after-school program and were developed to benefit the approximately 152,000 school-aged children who are served by NC after-school programs each year. These programs often serve children at high risk for physical inactivity, including children from racial/ethnic minorities, impoverished areas, with disabilities, and/or living in neighborhoods with limited PA opportunities. The rationale for developing standards for PA in after-school programs is threefold: (1) such programs can provide enjoyable, safe, and age-appropriate PA; (2) they can facilitate family involvement, community partnership, and increase access to PA resources; and (3) they serve children at risk for inactivity. Recommended best practices are included for the following categories: time/intensity, qualified staff/training, curriculum, program size, facilities, equipment, and evaluation. Methods used to inform The Standards included a planning team, on-line surveys, focus groups, a systematic literature review, a consensus panel, and external expert review. The impact of The Standards is yet to be seen, but the collaborative process used in their creation can serve as a model for the development of similar PA standards in other states.

Elevating physical activity as a public health priority: creation of the National Society of Physical Activity Practitioners in Public Health.

BACKGROUND: Physical activity has emerged as a distinct area of public health practice. As this field evolved, the need for a professional organization for physical activity practitioners in public health became evident. A collaboration of several existing public health professional organizations formed to address this new area of public health practice. The collaboration laid the foundation to establish a professional organization. National Association of Physical Activity Practitioners in Public Health (NSPAPPH) was launched in April 2006. NSPAPPH accomplishments to date include convening a national meeting of physical activity practitioners, conducting strategic planning, adopting bylaws and core competencies for professional practice, developing a website and electronic newsletter, and establishing training opportunities for practitioners. CONCLUSIONS: Future plans for NSPAPPH include development of a professional certification for physical activity practitioners in public health; enhancement of training and professional development opportunities; recruitment of members from national, tribal, state, and local organizations working in public and private sectors; publications of journal articles, reports, and issue briefs; and development of a policy agenda. Implementing these plans will serve to strengthen public health infrastructure for physical activity, thus improving the physical activity behaviors of Americans and the health of the nation.

The Move More Scholars Institute: a state model of the physical activity and public health practitioners course.

Physical activity has been identified as a public health priority. In response, training and professional development opportunities have been created to increase the capacity of public health practitioners to address this issue. Currently, training resources are primarily reaching national- and state-level professionals. Local-level physical activity and public health practitioners can also benefit from these resources. The Move More Scholars Institute, a 4-day training course for community-based physical activity practitioners in North Carolina, was developed for local practitioners. This article will describe the planning of, implementation of, and initial response to the Move More Scholars Institute.