1,010 research outputs found

    Deployment operation procedures for the WHOI Ice-Tethered Profiler

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    Deployed and fixed to a suitable multi-year ice floe, the Ice-Tethered Profiler (ITP) can sustain near-real time measurements of upper ocean temperature and salinity for up to three years. Incorporating a specifically designed winch system and deployment apparatus that is both light weight and easily assembled or disassembled on a ship or at a deployment site, the ITP can be deployed in less than four hours by either transporting the gear and field personnel to the deployment site via aircraft, or by lowering the gear over the side of a ship and hauling on the ice. Using daily satellite imagery (if available), visual reconnaissance flights, and ice surveying, the choice of an appropriate ice floe is a necessity to select a site that will sustain the system for a prolonged period of time (depending upon the instrument sampling rate). If available, the helicopter is the preferable method for surveying different sites and for deployment operations. Working from a ship typically limits the distance and selection of ice floes. Pre-deployment procedures include powering and configuring the ITP instruments and preparing the apparatus for transport to the deployment site. Specific deployment methods include the assembly and disassembly of the ITP winch, proper placement of the total ITP deployment apparatus, ‘Yale Grip’ braiding and slipping techniques, and testing the Iridium and Inductive communication links. The operations described here provide a safe and efficient manner to easily deploy the WHOI ITP.Funding was provided by the National Science Foundation under Grant No. OCE-0324233 and by the Office of Polar Programs under award numbers ARC-0519899 and ARC-0631951

    Beaufort Gyre Freshwater Experiment : deployment operations and technology 2003

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    The Beaufort Gyre Freshwater Experiment (BGFE) observational program was designed to measure the freshwater content of the upper ocean and sea ice in the Beaufort Gyre of the Arctic Ocean using bottom-tethered moorings, drifting buoys, and hydrographic stations. The mooring program required the development of a safe and efficient deployment method by which the subsurface system could be deployed in waters surrounded by sea ice. This report documents the mooring procedure used to deploy the three BGFE moorings from the CCGS Louis S. St- Laurent, during the Joint Western Arctic Climate Study – 2003 (August 6 – September 7). The technical details of the instrumentation attached to each mooring and the specific deployment parameters are described. Specifics pertaining to the deployment of four surface-tethered drifters in the ice are also documented.Funding was provided by the National Science Foundation under Grant Number OPP-0230184

    The Beaufort Gyre Observing System 2004 : mooring recovery and deployment operations in pack ice

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    Situated beneath the Arctic perennial ice pack, the principal components of the Beaufort Gyre Observing System are three deep-ocean bottom-tethered moorings with CTD and velocity profilers, upward looking sonars for ice draft measurements, and bottom pressure recorders. A major goal of this project is to investigate basin-scale mechanisms regulating freshwater and heat content in the Arctic Ocean and particularly in the Beaufort Gyre throughout several complete annual cycles. The methods of recovering and re-deploying the 3800 m long instrumented moorings from the Canadian Coast Guard Icebreaker Louis S. St. Laurent in August 2004 are described. In ice-covered regions, deployments must be conducted anchor-first, so heavier wire rope and hardware must be incorporated into the mooring design. Backup buoyancy at the bottom of the mooring is advised for backup recovery should intermediate lengths of the mooring system get tangled under ice floes during recovery. An accurate acoustic survey to determine the exact location of the mooring, adequate ice conditions, and skilled ship maneuvering are all essential requirements for a successful mooring recovery. Windlass (or capstan) procedures could be used for the recovery, but a traction winch arrangement is recommended.Funding was provided by the National Science Foundation under Grant Number OPP-0230184 and Woods Hole Oceanographic Insitution’s Ocean and Climate Change Institute

    The psychological impact of COVID19 on a shielding high-risk cohort

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    {2,6-Bis[(di-tert-butyl­phosphino)­methyl]­phenyl}chloridonickel(II)

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    In the title compound, [Ni(C24H43P2)Cl], the Ni atom adopts a distorted square-planar geometry, with the P atoms of the 2,6-bis­[(di-tert-butyl­phosphino)meth­yl]phenyl ligand trans to one another. The P—Ni—P plane is twisted out of the plane of the aromatic ring by 21.97 (6)°

    1,3-Bis(phenyl­sufanylmeth­yl)benzene

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    The complete mol­ecule of the title compound, C20H18S2, is generated by crystallographic mirror symmetry, with two C atoms lying on the mirror plane. All of the independent atoms are contained within two planes defined by the thio­phenyl rings (C6S) and the central phenyl ring with the methyl­ene bridge; the r.m.s deviations of these planes are 0.012 and 0.025 Å, respectively. The two planes are almost perpendicular to one another at a dihedral angle of 80.24 (10)°. Inter­molecular C—H—π inter­actions are present in the crystal structure

    Recognition of envelope and tat protein synthetic peptide analogs by HIV positive sera or plasma

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    AbstractA series of synthetic peptides corresponding to segments of HIV encoded proteins were selected using criteria described by Welling et al. [(1985) FEBS Lett. 188, 215]. Synthetic peptide analogs to gpl20 (2–13), (55–65), gp41 (582–596) (659–670) and tatIII (71–83) were recognized by 41–67% of sera or plasma from individuals known to be infected with HIV on the basis of virus isolation or Western blot screening. The peptide which reacted with most sera or plasma was gp41 (582–596), a conserved region in the transmembrane glycoprotein. An extended peptide analog, gp41 (579–599), tested against the same samples showed almost 100% reactivity, confirming independent studies identifying a highly immunodominant region of gp41. There was an unexpected high prevalence of antibodies (52%) to the tatIII peptide

    Photovoltaic self-assembly.

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    This late-start LDRD was focused on the application of chemical principles of self-assembly on the ordering and placement of photovoltaic cells in a module. The drive for this chemical-based self-assembly stems from the escalating prices in the 'pick-and-place' technology currently used in the MEMS industries as the size of chips decreases. The chemical self-assembly principles are well-known on a molecular scale in other material science systems but to date had not been applied to the assembly of cells in a photovoltaic array or module. We explored several types of chemical-based self-assembly techniques, including gold-thiol interactions, liquid polymer binding, and hydrophobic-hydrophilic interactions designed to array both Si and GaAs PV chips onto a substrate. Additional research was focused on the modification of PV cells in an effort to gain control over the facial directionality of the cells in a solvent-based environment. Despite being a small footprint research project worked on for only a short time, the technical results and scientific accomplishments were significant and could prove to be enabling technology in the disruptive advancement of the microelectronic photovoltaics industry
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