232 research outputs found

    Teaching English/Spanish Cognates to Increase Reading Comprehension

    Get PDF
    A curriculum has been developed for middle school English as a Second Language (ESL) students to improve their reading comprehension. A review of the literature found that vocabulary is an essential part of reading comprehension and becoming aware of English/Spanish cognates can increase the students\u27 English vocabulary. The curriculum includes a survey to assess a student\u27s knowledge and use of cognates, lesson plans to introduce the concept of cognates, to practice recognizing English/Spanish cognates, and learn the correlation of suffixes between English and Spanish. The curriculum also includes lists of English/Spanish cognates divided by subjects

    The donor OH stretching–libration dynamics of hydrogen-bonded methanol dimers in cryogenic matrices

    Get PDF
    FTIR spectra of the methanol dimer trapped in neon matrices are presented.</p

    JET-FTIR-SPECTROSCOPY OF PYRROLE CLUSTERS

    Get PDF
    Author Institution: Institut fur Physikalische Chemie, Universitat Gottingen, Tammannstr. 6, D-37077 Gottingen, GermanyJet-FTIR spectroscopy is a powerful technique to investigate small hydrogen bonded clusters} \textbf{118}, 2001, 331--359.}. The filet-jet-spectrometer combines a 600×0.2600\times0.2\,mm\textsuperscript{2} slit nozzle with a commercial FTIR-instrument} \textbf{219}, 2005, 379--388.}.\\ Pyrrole is a five-membered heterocyclic aromat with hydrogen bond donor (N--H) and acceptor (π\pi-system) functionalities. Weak \mbox{N--Hπ\cdots\pi} hydrogen bonds} \textbf{108}, 2004, 6953--6967.} play an important role in biological systems. Therefore, weakly bound aggregates of pyrrole and some of its methylated derivatives have been systematically characterised by the filet-jet-spectroscopy.\\ In pyrrole-2-carboxaldehyde, the additional carbonyl group offers a better hydrogen bond acceptor site and leads to the formation of more conventional N--H\cdotsO hydrogen bonds. Its dimer has therefore been investigated as a small model system for hydrogen bonding in peptides

    The effect of hydrogen bonding on torsional dynamics: A combined far-infrared jet and matrix isolation study of methanol dimer.

    Get PDF
    The effect of strong intermolecular hydrogen bonding on torsional degrees of freedom is investigated by far-infrared absorption spectroscopy for different methanol dimer isotopologues isolated in supersonic jet expansions or embedded in inert neon matrices at low temperatures. For the vacuum-isolated and Ne-embedded methanol dimer, the hydrogen bond OH librational mode of the donor subunit is finally observed at ∼560 cm(-1), blue-shifted by more than 300 cm(-1) relative to the OH torsional fundamental of the free methanol monomer. The OH torsional mode of the acceptor embedded in neon is observed at ∼286 cm(-1). The experimental findings are held against harmonic predictions from local coupled-cluster methods with single and double excitations and a perturbative treatment of triple excitations [LCCSD(T)] and anharmonic. VPT2 corrections at canonical MP2 and density functional theory (DFT) levels in order to quantify the contribution of vibrational anharmonicity for this important class of intermolecular hydrogen bond vibrational motion

    PROPERTIES OF SIZE SELECTED SODIUM DOPED SOLVENT CLUSTERS

    Get PDF
    Author Institution: Max-Planck-Institut fur Dynamik und Selbstorganisation, Bunsenstr. 10, D-37073 Gottingen, Germany; Institut fur Physikalische Chemie, Universitat Gottingen, Tammannstr. 6, D-37077 Gottingen, GermanyThe properties of hydrogen bonded solvent clusters are investigated with a size selective molecular beam experiment. The doped solvent clusters were generated in a continuous supersonic pinhole expansion and were photoionized by a tunable dye laser system, follwed by mass analysis in a reflectron time-of-flight mass spectrometer.\\ Sodium doped ammonia clusters show a strong size dependence of the ionization potential (IP). It decreases with the size of the clusters} \textbf{122}, 2005, 134301.}. The IPs of sodium doped water clusters Na(H2O)n\mathrm{Na(H_2O)_n} only show a size dependent decrease for clusters up to n=4. For larger clusters a constant IP is found} \textbf{67}, 1991, 1767-1770.}.\\ The IPs provide important information on the cluster structures. Currently, size selective properties of sodium doped methanol clusters are being investigated, to learn more about the structures of these clusters and the solvated electrons.\

    Rovibronic signatures of molecular aggregation in the gas phase: subtle homochirality trends in the dimer, trimer and tetramer of benzyl alcohol.

    Get PDF
    [EN]Molecular aggregation is of paramount importance in many chemical processes, including those in living beings. Thus, characterization of the intermolecular interactions is an important step in its understanding. We describe here the aggregation of benzyl alcohol at the molecular level, a process governed by a delicate equilibrium between OHMIDLINE HORIZONTAL ELLIPSISO and OHMIDLINE HORIZONTAL ELLIPSIS pi hydrogen bonds and dispersive interactions. Using microwave, FTIR, Raman and mass-resolved double-resonance IR/UV spectroscopic techniques, we explored the cluster growth up to the tetramer and found a complex landscape, partly due to the appearance of multiple stereoisomers of very similar stability. Interestingly, a consistently homochiral synchronization of transiently chiral monomer conformers was observed during cluster growth to converge in the tetramer, where the fully homochiral species dominates the potential energy surface. The data on the aggregation of benzyl alcohol also constitute an excellent playground to fine-tune the parameters of the most advanced functionals.The Gottingen part of the project was partly funded by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) - 271107160/SPP1807. We thank M. Lange and E. K. M. M. Sennert for the measurement of the FTIR spectrum and E. Meyer for help with the measurement of the Raman spectrum. Computational resources from the GWDG and the Gottingen Faculty of Chemistry (DFG - 405832858/INST 186/1294-1 FUGG) are acknowledged. We thank the Gottingen chemistry workshops for valuable support. This publication was supported financially by the Open Access Grant Program of the DFG and the Open Access Publication Fund of the University of Gottingen. The Bilbao and Valladolid groups acknowledge funding from the Spanish Ministerio de Ciencia e Innovacion (MICINN-FEDER PGC2018-098561-B-C21 and PGC2018-098561-B-C22). Bilbao's group also thank the SGIKER (UPV/EHU, MICIU-FEDER) for the computational and laser resources. The Hamburg part of this work was financially supported by the Deutsche Forschungsgemeinschaft (SCHN1280/4-2, project number 271359857) in the context of the priority program SPP 1807 "Control of London dispersion interactions in molecular chemistry". P. Pinacho would like to thank the Alexander von Humboldt Foundation for a postdoctoral fellowship

    The furan microsolvation blind challenge for quantum chemical methods: First steps

    Get PDF
    © 2018 Author(s). Herein we present the results of a blind challenge to quantum chemical methods in the calculation of dimerization preferences in the low temperature gas phase. The target of study was the first step of the microsolvation of furan, 2-methylfuran and 2,5-dimethylfuran with methanol. The dimers were investigated through IR spectroscopy of a supersonic jet expansion. From the measured bands, it was possible to identify a persistent hydrogen bonding OH-O motif in the predominant species. From the presence of another band, which can be attributed to an OH-π interaction, we were able to assert that the energy gap between the two types of dimers should be less than or close to 1 kJ/mol across the series. These values served as a first evaluation ruler for the 12 entries featured in the challenge. A tentative stricter evaluation of the challenge results is also carried out, combining theoretical and experimental results in order to define a smaller error bar. The process was carried out in a double-blind fashion, with both theory and experimental groups unaware of the results on the other side, with the exception of the 2,5-dimethylfuran system which was featured in an earlier publication

    Stratus 10 tenth setting of the Stratus Ocean Reference Station : cruise RB-10-01, January 2 - January 30, 2010 Charleston, South Carolina - Valparaiso, Chile

    Get PDF
    The Ocean Reference Station at 20°S, 85°W under the stratus clouds west of northern Chile is being maintained to provide ongoing climate-quality records of surface meteorology, air-sea fluxes of heat, freshwater, and momentum, and of upper ocean temperature, salinity, and velocity variability. The Stratus Ocean Reference Station (ORS Stratus) is supported by the National Oceanic and Atmospheric Administration’s (NOAA) Climate Observation Program. It is recovered and redeployed annually, with past cruises that have come between October and December. Due to necessary repairs on the electric motors of the ship’s propulsion system, this year the cruise was delayed until January. During the 2009/2010 cruise on the NOAA ship Ronald H. Brown to the ORS Stratus site, the primary activities were the recovery of the Stratus 9 WHOI surface mooring that had been deployed in October 2008, deployment of a new (Stratus 10) WHOI surface mooring at that site, in-situ calibration of the buoy meteorological sensors by comparison with instrumentation installed on the ship by staff of the NOAA Earth System Research Laboratory (ESRL), and collection of underway and on station oceanographic data to continue to characterize the upper ocean in the stratus region. Both underway CTD (UCTD) profiles and Vertical Microstructure Profiles (VMP) were collected along the track and during surveys dedicated to investigating eddy variability in the region. Surface drifters were also launched along the track. The intent was also to visit a buoy for the Pacific tsunami warning system maintained by the Hydrographic and Oceanographic Service of the Chilean Navy (SHOA). This DART (Deep- Ocean Assessment and Reporting of Tsunami) buoy had been equipped with IMET sensors and subsurface oceanographic instruments, and a recovery and replacement of the IMET sensors was planned. However, the DART buoy broke free from its mooring on January 3rd and was recovered by the Chilean navy; the work done at that site during this cruise was the recovery of the bottom pressure unit.Funding was provided by the National Oceanic and Atmospheric Administration under Grant No. NA17RJ1223 for the Cooperative Institute for Climate and Ocean Research (CICOR)

    Capture the fracture: a best practice framework and global campaign to break the fragility fracture cycle

    Get PDF
    Summary The International Osteoporosis Foundation (IOF) Capture the Fracture Campaign aims to support implementation of Fracture Liaison Services (FLS) throughout the world. Introduction FLS have been shown to close the ubiquitous secondary fracture prevention care gap, ensuring that fragility fracture sufferers receive appropriate assessment and intervention to reduce future fracture risk. Methods Capture the Fracture has developed internationally endorsed standards for best practice, will facilitate change at the national level to drive adoption of FLS and increase awareness of the challenges and opportunities presented by secondary fracture prevention to key stakeholders. The Best Practice Framework (BPF) sets an international benchmark for FLS, which defines essential and aspirational elements of service delivery. Results The BPF has been reviewed by leading experts from many countries and subject to beta-testing to ensure that it is internationally relevant and fit-for-purpose. The BPF will also serve as a measurement tool for IOF to award ‘Capture the Fracture Best Practice Recognition’ to celebrate successful FLS worldwide and drive service development in areas of unmet need. The Capture the Fracture website will provide a suite of resources related to FLS and secondary fracture prevention, which will be updated as new materials become available. A mentoring programme will enable those in the early stages of development of FLS to learn from colleagues elsewhere that have achieved Best Practice Recognition. A grant programme is in development to aid clinical systems which require financial assistance to establish FLS in their localities. Conclusion Nearly half a billion people will reach retirement age during the next 20 years. IOF has developed Capture the Fracture because this is the single most important thing that can be done to directly improve patient care, of both women and men, and reduce the spiralling fracture-related care costs worldwide.</p

    A microLed imager for AR headset for use in high luminance environment

    Get PDF
    Today, popular Augmented Reality headsets suffer from a lack of brightness to allow the diffusion of readable information against a very bright landscape, in particular for avionics use, and more generally, outdoor applications.We present in this paper, the project “HiLICo”, aiming to develop an emissive GaN micro-displays with 1640 x 1032 pixel resolution (WUXGA), 9.5-|jm pixel pitch, very high brightness (over 1Mcd/ cm2) and good form factor capabilities that will enable the design of ground breaking compact see-through system for next generation Avionics applications
    corecore