NASA's Planned Return to the Moon: Global Access and Anytime Return Requirement Implications on the Lunar Orbit Insertion Burns

Lunar orbit insertion LOI is a critical maneuver for any mission going to the Moon. Optimizing the geometry of this maneuver is crucial to the success of the architecture designed to return humans to the Moon. LOI burns necessary to meet current NASA Exploration Constellation architecture requirements for the lunar sortie missions are driven mainly by the requirement for global access and "anytime" return from the lunar surface. This paper begins by describing the Earth-Moon geometry which creates the worst case (delta)V for both the LOI and the translunar injection (TLI) maneuvers over the full metonic cycle. The trajectory which optimizes the overall (delta)V performance of the mission is identified, trade studies results covering the entire lunar globe are mapped onto the contour plots, and the effects of loitering in low lunar orbit as a means of reducing the insertion (delta)V are described. Finally, the lighting conditions on the lunar surface are combined with the LOI and TLI analyses to identify geometries with ideal lighting conditions at sites of interest which minimize the mission (delta)V

Electronic modulation of infrared emissivity in graphene plasmonic resonators

Electronic control of blackbody emission from graphene plasmonic resonators on a silicon nitride substrate is demonstrated at temperatures up to 250 C. It is shown that the graphene resonators produce antenna-coupled blackbody radiation, manifest as narrow spectral emission peaks in the mid-IR. By continuously varying the nanoresonators carrier density, the frequency and intensity of these spectral features can be modulated via an electrostatic gate. We describe these phenomena as plasmonically enhanced radiative emission originating both from loss channels associated with plasmon decay in the graphene sheet and from vibrational modes in the SiNx.Comment: 17 pages, 6 figure

Taking charge at work: the mediating role of role breadth self-efficacy

This study examines the motivational process of taking charge among the general working population. Specifically, this study attempts to investigate the impact of proactive personality and co-worker support on taking charge. In addition, this study recognises the significance of proactive motivational states in stimulating proactive goal regulation and striving. By incorporating role breadth self-efficacy (RBSE) to represent the can-do motivational state, this study also seeks to understand whether RBSE mediates the relationships between the antecedents and taking charge. The hypothesised model was tested using mediation analysis on a sample of 193 individuals, mainly working in Malaysia’s organisations and holding different positions. The findings show that proactive personality and co-worker support were significantly and positively related to taking charge. Moreover, the study confirms that RBSE mediates the relationships between proactive personality and taking charge and co-worker support and taking charge. The paper represents one of the few attempts to study the effects of both proactive personality and co-worker support on taking charge. Distinctly, the study confirms employees’ personalities as a more significant determinant of taking charge than co-worker support among the samples. Likewise, by confirming the mediation effects of RBSE, the findings further imply that practitioners should make an effort to enhance employees’ RBSE to develop taking charge, which is helpful to ensure organisational sustainability

Highly Confined Tunable Mid-Infrared Plasmonics in Graphene Nanoresonators

Single-layer graphene has been shown to have intriguing prospects as a plasmonic material, as modes having plasmon wavelengths 20 times smaller than free space (λ_p ~ λ_0/20) have been observed in the 2–6 THz range, and active graphene plasmonic devices operating in that regime have been explored. However there is great interest in understanding the properties of graphene plasmons across the infrared spectrum, especially at energies exceeding the graphene optical phonon energy. We use infrared microscopy to observe the modes of tunable plasmonic graphene nanoresonator arrays as small as 15 nm. We map the wavevector-dependent dispersion relations for graphene plasmons at mid-infrared energies from measurements of resonant frequency changes with nanoresonator width. By tuning resonator width and charge density, we probe graphene plasmons with λ_p ≤ λ_0/100 and plasmon resonances as high as 310 meV (2500 cm^–1) for 15 nm nanoresonators. Electromagnetic calculations suggest that the confined plasmonic modes have a local density of optical states more than 10^6 larger than free space and thus could strongly increase light–matter interactions at infrared energies

International Collaboration on a Sustainable Forestry Management OER Online Program – A Case Study

[EN] Over time, forest education has had to adapt to keep up with global changes and to accomodate the needs of students and society. While facing pressing global issues like climate change, deforestation, illegal logging and food security, the role of higher forest education has shifted away from traditional teaching approaches and practices to methods that emphasize sustainable development, community-based management and environmental conservation in forestry. In doing so, forest education has cultivated human expertise that understands the complexity of ever-changing environments, masters state of the art technologies to manage fores and natural resources, and is capable of creating, communicating and implementing related policies in global communities and societies. In this context, educational technology and online lerning enable flexible, accessible, effective, and high-quality forest education. A case study of a Sustainable Forest Management Online program led by the Faculty of Forestry, University of British Columbia (UBC) shows that appropriately integrating educational technologies into an interntionally developed and recognized high quality curriculum is an effective way to create accessible and affordable forest education in meeting the demand of evolving societal and environmental conditions.Keywords: forest education; educational technology; international collaboration, open educational resourcesThis paper is based on studies conducted along with the delivery of a series of online courses in sustainable forest management supported by the Asia-Pacific Network for Sustainable Forest Management (APFNet) and the Asia Pacific Forestry Education Coordination Mechanism (AP-FECM).Zeng, MQ(.; Chen, H.; Shrestha, A.; Crowley, C.; Ng, E.; Wang, G. (2020). International Collaboration on a Sustainable Forestry Management OER Online Program – A Case Study. En 6th International Conference on Higher Education Advances (HEAd'20). Editorial Universitat Politècnica de València. (30-05-2020):1253-1260. https://doi.org/10.4995/HEAd20.2020.112421253126030-05-202

A Randomized Trial Examining Preoperative Sedative Medication and Post-operative Sleep in Children

Study Objective Midazolam has been found to have beneficial effects on anxiety in children in the preoperative setting. Prior studies have examined various postoperative behaviors of children, but little research has examined the effects of preoperative use of midazolam with postoperative sleep. The purpose of this investigation was to compare postoperative sleep in children as a function of preoperative sedative medication use. Design This study was a 2-group randomized controlled trial. Setting Participants were recruited from Yale-New Haven Children\u27s Hospital. Patients Participants included a convenience sample of 70 children between the ages of 3 to 12 years undergoing ambulatory tonsillectomy and adenoidectomy. Interventions Children were randomly assigned to 1 of 2 groups: a control group who received preoperative acetaminophen only (n = 32) and an experimental group who received both acetaminophen and midazolam preoperatively (n = 38). Measurements Parents completed measures of postoperative behavioral recovery and a subset of children wore actigraphs to examine objective sleep data. Main Results Children who received midazolam experienced similar sleep changes compared to children in the control group. The actigraph data revealed that children who received midazolam were awake significantly less during the night compared to the control group (P= .01). Conclusion Children who received midazolam before surgery had similar postoperative sleep changes compared to children who did not receive midazolam. Further understanding of the postoperative behavioral effects of midazolam on children will help guide healthcare providers in their practice