Velocity map imaging of the dynamics of the CH3 + HCl -> CH4 + Cl reaction using a dual molecular beam method

International audienceThe reactions CH3 + HCl → CH4 + Cl(²P_3/2) and CD₃ + HCl → CD₃H + Cl(²P_3/2) have been studied by photo-initiation (by CH₃I or CD₃I photolysis at 266 nm) in a dual molecular beam apparatus. Product Cl(²P</sub>3/2</sub>) atoms were detected using resonance enhanced multi-photon ionisation and velocity map imaging, revealing product translational energy and angular scattering distributions in the centre-of-mass frame. Image analysis is complicated by the bimodal speed distribution of CH₃ (and CD₃) radicals formed in coincidence with I(²P_3/2) and I(²P_1/2) atoms from CH₃I (CD₃I) photodissociation, giving overlapping Newton diagrams with displaced centre of mass velocities. The relative reactivities to form Cl atoms are greater for the slower CH₃ speed group than the faster group by factors of ~1.5 for the reaction of CH₃ and ~2.5 for the reaction of CD₃, consistent with the greater propensity of the faster methyl radicals to undergo electronically adiabatic reactions to form Cl(²P_1/2). The average fraction of the available energy becoming product translational energy is = 0.48 ± 0.05 and 0.50 ± 0.03 for reaction of the faster and slower sets of CH₃ radicals, respectively. The Cl atoms are deduced to be preferentially forward scattered with respect to the HCl reagents, but the angular distributions from the dual beam imaging experiments require correction for under-detection of forward scattered Cl products

Late Preterm and Early Term Birth: At-risk Populations and Targets for Reducing Such Early Births

The risks of late preterm (LPT) and early term (ET) birth have been recognized during the last decade. Increased awareness accompanied by efforts to reduce elective delivery before 39 weeks of gestation have led to a decline in LPT/ET births. Despite this success, strategies to identify and reduce preventable LPT/ET births using traditional and novel prevention methods are still needed. Because preterm birth is a common endpoint associated with many different preventable and nonpreventable causes, the efforts for reducing such early births must be multifaceted. For neonates born LPT/ET, there is an inverse relationship between gestational age and morbidity and mortality, with a nadir at 39 to 40 weeks of gestation. Recognition of the short-term complications of LPT/ET is important for timing of delivery and the initial clinical management of these patients. In addition, the recognition of the long-term respiratory and neurocognitive complications of LPT/ET birth helps inform the evaluation, treatment, and monitoring for impairments and disabilities that benefit from early detection and intervention. In this article, we review the definition of LPT/ET birth, prevention strategies, indications for LPT/ET birth, and the short- and long-term outcomes for such infants

Effective Collaborations in Multi-Campus and Online Environments Using LibGuides

The paper presents a series of case studies that describe and demonstrate successful collaborations created via partnerships with instructors, departments, and other groups in both multi-campus and online environments at Georgia Perimeter College (GPC) where all three authors worked together as librarians for five years. The case studies illustrate the use of LibGuides in building librarian-librarian and librarian-­faculty partnerships to support teaching and other campus activities. This discussion includes successful strategies for establishing connections and adopting LibGuides as communication tool for collaborative projects

Assessing Faculty Awareness of Library Services in Two Georgia Undergraduate Institutions

In order to ascertain faculty awareness of library resources and services, librarians at two Georgia intuitions, Georgia Perimeter College and Oglethorpe University, joined forces to conduct a survey in 2012. The results were surprising and challenging, yet productive in forming a benchmark for further collaboration between librarians and faculty in student use of library services and resources