Control of metal-organic framework (MOF) crystal alignment and orientation by electric field

Due to most Metal-Organic Frameworks (MOFs) possessing anisotropic properties, it could prove extremely useful to control and manipulate their alignment and orientation. Such control of MOF crystal microrods has previously been demonstrated by use of a magnetic field as part of a collaboration between the University of Hull (UK), University of Vienna (Austria) and Northwestern University (USA). Following on this work, here we show that similar methods can be exploited in order to dynamically align MOF crystals NU-1000 by applying an electric field, making it directly compatible with device integration. Experiments have been performed on this MOF in the form of two different samples: i) an unfixed suspension in bromobenzene allowing for dynamic and reconfigurable alignment and ii) a solid sample with the MOF alignment fixed in place by resin curing. The alignment of the NU-1000 was then confirmed and quantified by studying the fluorescence emission under polarised excitation, taking advantage of the absorption anisotropy. A laser emitting light of wavelength 405nm was used to excite the samples and the resulting fluorescence was measured as a function of the incident angle of polarisation relative to the orientation of the NU-1000 crystal. In a second stage, the emission and absorption polarisation properties of the aligned MOF samples were measured. It was found that the fluorescence emission, as well as the absorption, are polarised along the MOF crystal long axis. This work and potential future work has applications in optics and electronics such as energy transfer, gas sensing and separation, display technology and optical switches

Orofacial manual therapy improves cervical movement impairment associated with headache and features of temporomandibular dysfunction: A randomized controlled trial

There is evidence that temporomandibular disorder (TMD) may be a contributing factor to cervicogenic headache (CGH), in part because of the influence of dysfunction of the temporomandibular joint on the cervical spine. The purpose of this randomized controlled trial was to determine whether orofacial treatment in addition to cervical manual therapy, was more effective than cervical manual therapy alone on measures of cervical movement impairment in patients with features of CGH and signs of TMD. In this study, 43 patients (27 women) with headache for more than 3-months and with some features of CGH and signs of TMD were randomly assigned to receive either cervical manual therapy (usual care) or orofacial manual therapy to address TMD in addition to usual care. Subjects were assessed at baseline, after 6 treatment sessions (3-months), and at 6-months follow-up. 38 subjects (25 female) completed all analysis at 6-months follow-up. The outcome criteria were: cervical range of movement (including the C1-2 flexion-rotation test) and manual examination of the upper 3 cervical vertebra. The group that received orofacial treatment in addition to usual care showed significant reduction in all aspects of cervical impairment after the treatment period. These improvements persisted to the 6-month follow-up, but were not observed in the usual care group at any point. These observations together with previous reports indicate that manual therapists should look for features of TMD when examining patients with headache, particularly if treatment fails when directed to the cervical spine

The Importance of Retrieval Failures to Long-term Retention: A Metacognitive Explanation of the Spacing Effect

Encoding strategies vary in their duration of effectiveness, and individuals can best identify and modify strategies that yield effects of short duration on the basis of retrieval failures. Multiple study sessions with long inter-session intervals are better than massed training at providing discriminative feedback that identifies encoding strategies of short duration. We report two investigations in which long intervals between study sessions yield substantial benefits to long-term retention, at a cost of only moderately longer individual study sessions. When individuals monitor and control encoding over an extended period, targets yielding the largest number of retrieval failures contribute substantially to the spacing advantage. These findings are relevant to theory and to educators whose primary interest in memory pertains to long-term maintenance of knowledge

If they all had a Heart Like You

https://digitalcommons.library.umaine.edu/mmb-vp/3588/thumbnail.jp

Time resolved structural dynamics of butadiyne-linked porphyrin dimers

In this work the timescales and mechanisms associated with the structural dynamics of butadiyne-linked porphyrin dimers are investigated through time resolved narrowband pump / broadband probe transient absorption spectroscopy. Our results confirm previous findings that the broadening is partly due to a distribution of structures with different (dihedral) angular conformations. Comparison of measurements with excitations on the red and blue sides of the Q-band unravel the ground and excited state conformational re-equilibration timescales. Further comparison to a planarized dimer, through addition of a ligand, provide conclusive evidence for the twisting motion performed by the porphyrin dimer in solution

Using End-of-Course Student Survey Data to Investigate Faculty Effectiveness

This research analyzed school of business faculty effectiveness controlling for the mode of delivery using over 50,000 student end-of-course (EOC) surveys. The surveys were collected for the year July 2011 through June 2012 from adult programs at the school of business and leadership of a private, Christian university. The findings indicate that full-time faculty members receive slightly higher ratings compared to adjunct faculty when the mode of delivery was on-site. However, adjunct faculty members were perceived as more effective than fulltime faculty when the mode of delivery was online. Ratings were higher for full-time faculty on-site compared to full-time faculty online and ratings were higher for adjunct faculty on-site compared to adjunct faculty online