An \u3cem\u3eIn Vitro\u3c/em\u3e Spectroscopic Analysis to Determine the Chemical Composition of the Precipitate Formed by Mixing Sodium Hypochlorite and Chlorhexidine

Introduction—The purpose of this in vitro study was to determine the chemical composition of the precipitate formed by mixing sodium hypochlorite (NaOCl) and Chlorhexidine (CHX), and relative molecular weight of the components. Methods—Using commercially available chlorhexidine gluconate (CHXg), a 2% solution was formed and mixed in a 1:1 ratio with commercially available NaOCl producing a brown precipitate. The precipitate as well as a mixture of precipitate and pure chlorhexidine diacetate (CHXa) was then analyzed using 1D and 2D NMR spectroscopy. Results—The 1D and 2D NMR spectra were fully assigned, in terms of chemical shifts of all proton and carbon atoms in intact CHX. This permitted identification of CHX breakdown products with and without the aliphatic linker present, including lower molecular weight components of CHX that contained a para-substituted benzene that was not para-chloroaniline (PCA). Conclusions—Based on this in vitro study, the precipitate formed by NaOCl and CHX is composed of at least two separate molecules, all of which are smaller in size than CHX. Along with native CHX, the precipitate contains two chemical fragments derived from CHX, neither of which are PCA

Quantum Deformations of Space-Time Symmetries with Mass-Like Deformation Parameter

The difficulties with the measurability of classical space-time distances are considered. We outline the framework of quantum deformations of D=4 space-time symmetries with dimensionfull deformation parameter, and present some recent results.Comment: 4 pages, LaTeX, uses file stwol.sty, to be published in the Proceedings of XXXII International Rochester Conference in High Energy Physics (Warsaw, 24.07-31.07 1996

Explaining the effectiveness of performance-based logistics: a quantitative examination

The article of record as published may be located at http://dx.doi.org/10.1108/09574091111181354Purpose – Performance-based logistics (PBL) strategies are providing governments and for-profit organizations with a contractual mechanism that reduces the life cycle costs of their systems. PBL accomplishes this by establishing contracts that focus on the delivery of performance not parts. PBL establishes a metric based governance structure where suppliers make more profit when they invest in logistics process improvements, or system redesign, that reduces total cost of ownership. While work has been done to outline an overall PBL theoretical framework, the underlying theory explaining the enablers that lead to organizational and team-level, team-goal alignment associated with the PBL governance structure requires testing. The purpose of this paper is to quantitatively test previously posited relationships between enablers of PBL and PBL effectiveness. An additional objective is to explore any differences in PBL effectiveness between different business sectors.This material is based upon work supported by the Naval Postgraduate School Acquisition Research Program under Grant No. N00244-10-1-0074

Fabrication system, method and apparatus for microelectromechanical devices

A fabrication system and method of fabrication for producing microelectromechanical devices such as field-effect displays using thin-film technology. A spacer is carried at its proximal end on the surface of a substrate having field-effect emitters with the spacer being enabled for tilting movement from a nested position to a deployed position which is orthogonal to the plane of the substrate. An actuator is formed with one end connected with the substrate and another end connected with spacer. The actuator is made of a shape memory alloy material which contracts when heated through the material's phase-change transition temperature. Contraction of the actuator exerts a pulling force on the spacer which is tilted to the deployed position. A plurality of the spacers are distributed over the area of the display. A glass plate having a phosphor-coated surface is fitted over the distal ends of the deployed spacer

Fluctuations of an Atomic Ledge Bordering a Crystalline Facet

When a high symmetry facet joins the rounded part of a crystal, the step line density vanishes as sqrt(r) with r denoting the distance from the facet edge. This means that the ledge bordering the facet has a lot of space to meander as caused by thermal activation. We investigate the statistical properties of the border ledge fluctuations. In the scaling regime they turn out to be non-Gaussian and related to the edge statistics of GUE multi-matrix models.Comment: Version with major revisions -- RevTeX, 4 pages, 2 figure

Potassium–carbonate co-substituted hydroxyapatite compositions : maximising the level of carbonate uptake for potential CO2 utilisation options

The authors would like to acknowledge the University of Aberdeen and the Royal Commission for the Exhibition of 1851 for providing financial support.CO2 utilisation is a rapidly growing area of interest aimed at reducing the magnitude of anthropogenic greenhouse gas emissions. We report the synthesis of potassium–carbonate (K–CO3) co-substituted hydroxyapatites with potassium and carbonate contents ranging from approximately 0.4–0.9 wt% and 3.4–13.0 wt% respectively via an aqueous precipitation reaction between calcium hydroxide, phosphoric acid and either potassium carbonate or potassium hydrogen–carbonate. The incorporated carbonate is situated on both hydroxyl and phosphate sites. A subsequent heat treatment in dry CO2 at 600 °C allowed for a K–CO3 co-substituted apatite containing approximately 16.9 wt% CO32− to be prepared, amongst the largest carbonate contents that have been reported for such a material to date. Although this work shows that K–CO3 co-substituted apatites with high levels of carbonate incorporation can be prepared using simple, room temperature, aqueous precipitation reactions with starting reagents unlikely to pose significant environmental risks, testing of these materials in prospective applications (such as solid fertilisers) is required before they can be considered a viable CO2 utilisation option. A preliminary assessment of the effect of potassium/carbonate substitution on the solubility of the as-prepared compositions showed that increasing carbonate substitution increased the solubility.Publisher PDFPeer reviewe

Future Antarctic bed topography and its implications for ice sheet dynamics

The Antarctic bedrock is evolving as the solid Earth responds to the past and ongoing evolution of the ice sheet. A recently improved ice loading history suggests that the Antarctic Ice Sheet (AIS) has generally been losing its mass since the Last Glacial Maximum. In a sustained warming climate, the AIS is predicted to retreat at a greater pace, primarily via melting beneath the ice shelves. We employ the glacial isostatic adjustment (GIA) capability of the Ice Sheet System Model (ISSM) to combine these past and future ice loadings and provide the new solid Earth computations for the AIS. We find that past loading is relatively less important than future loading for the evolution of the future bed topography. Our computations predict that the West Antarctic Ice Sheet (WAIS) may uplift by a few meters and a few tens of meters at years AD 2100 and 2500, respectively, and that the East Antarctic Ice Sheet is likely to remain unchanged or subside minimally except around the Amery Ice Shelf. The Amundsen Sea Sector in particular is predicted to rise at the greatest rate; one hundred years of ice evolution in this region, for example, predicts that the coastline of Pine Island Bay will approach roughly 45 mm yr−1 in viscoelastic vertical motion. Of particular importance, we systematically demonstrate that the effect of a pervasive and large GIA uplift in the WAIS is generally associated with the flattening of reverse bed slope, reduction of local sea depth, and thus the extension of grounding line (GL) towards the continental shelf. Using the 3-D higher-order ice flow capability of ISSM, such a migration of GL is shown to inhibit the ice flow. This negative feedback between the ice sheet and the solid Earth may promote stability in marine portions of the ice sheet in the future

ISMIP6: Ice Sheet Model Intercomparison Project for CMIP6

ISMIP6 (Ice Sheet Model Intercomparison Project for CMIP6) targets the Cryosphere in a Changing Climate and the Future Sea Level Grand Challenges of the WCRP (World Climate Research Program). Primary goal is to provide future sea level contribution from the Greenland and Antarctic ice sheets, along with associated uncertainty. Secondary goal is to investigate feedback due to dynamic ice sheet models. Experiment design uses and augment the existing CMIP6 (Coupled Model Intercomparison Project Phase 6) DECK (Diagnosis, Evaluation, and Characterization of Klima) experiments. Additonal MIP (Model Intercomparison Project)- specific experiments will be designed for ISM (Ice Sheet Model). Effort builds on the Ice2sea, SeaRISE (Sea-level Response to Ice Sheet Evolution) and COMBINE (Comprehensive Modelling of the Earth System for Better Climate Prediction and Projection) efforts