1. The Asbestos/Carbon Nanotube Analogy: Will there be an epidemic of nanodiseases in 2030?


    from LBNL Earth Sciences Division Added 152 0 0

    Asbestos fibers were exploited commercially beginning in the early 20th century, with 50 million metric tons used between 1920-1970. Inhalation of asbestos fibers is associated with pulmonary fibrosis (asbestosis), lung and laryngeal cancers, and malignant mesothelioma, with a long latent period of 20-40 years. The 15-year cumulative mortality from malignant mesothelioma from 1994-2008 is 175,000 deaths. The physical and chemical properties of asbestos fibers related to carcinogenicity include fiber dimensions, surface reactivity, and biopersistence following inhalation into the lungs. Long, rigid fibrous materials trigger incomplete or frustrated phagocytosis by target cells in the lungs, resulting in impaired clearance and persistent release of reactive oxygen species and proinflammatory mediators. Direct intraperitoneal injection of carbon nanotubes has also been shown to induce malignant mesothelioma in mice. Carbon nanotubes have shapes and dimensions similar to asbestos fibers; however, their graphenic surface is hydrophobic, while crystalline mineral fibers are hydrophilic. Asbestos fibers and carbon nanotubes are biopersistent; however, carbon nanotubes can be chemically modified to accelerate their degradation by oxidants. Carbon nanotubes are a rapidly growing worldwide market, and production is projected to exceed 12,000 metric tons in 2016. At this early stage in commercialization, it should be possible to engineer less toxic, biocompatible, and biodegradable carbon nanotubes to minimize potential adverse health impacts.

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    • CaCO3 Prenucleation Clusters and Crystallization Control by Additives


      from LBNL Earth Sciences Division Added 264 1 0

      In this presentation, the earliest stages in the formation of a crystal will be discussed. For the example of stable prenucleation CaCO3 clusters, which can already be found prior to nucleation and even in undersaturated solution, it will be shown that an alternative crystallization pathway exists. Basic characterization of the clusters will be presented, and the driving forces for their formation will be discussed.

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      • Quantifying Surface Water-Groundwater Exchange


        from LBNL Earth Sciences Division Added 110 0 0

        Historical failure to recognise the connection between surface water and groundwater and to manage river and groundwater systems conjunctively has led to over allocation of water resources. Examples of river systems that have been depleted by groundwater pumping, for example, are well documented. Although conjunctive management of surface water and groundwater is preferred, it requires information on the magnitude of the interaction between the two reservoirs. While numerous different methods have been used to measure the exchange flux, the usefulness of many of these methods is limited by the very high spatial and temporal variability of the fluxes involved. Methods that have been used successfully to estimate spatial variations in groundwater discharge to streams, over scales of interest to water managers, include water and solute mass balances. Groundwater discharge to streams can be determined from differences between river flow gaugings made at different points along the river, and from measurements of conservative ion concentrations. Sensitivity is greatest, however, when tracers are used whose concentration in the groundwater greatly exceeds that in surface water. This condition is often best met for the naturally occurring radioactive element radon (222Rn). Since radon in surface water is lost by exchange with the atmosphere (which is low in radon), a large contrast in concentration with the groundwater is maintained. Measuring changes in groundwater discharge with time is more difficult, because the required frequency of measurements means that only parameters that can be measured remotely are suitable.

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        • DSSS


          from sweet skateboards Added 2,066 0 0

          DSSS (daniel spängs super session) is a birthdayparty for daniel spängs. this video is made by andreas andaloussi A.K.A maroci. many thanks to him. the video contains some skateboarding in the backyard ramp at the junk mansion, some drinking, pool activities etc..

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          • Stop It Before It Starts - Peel Skills Challenge PSA 2015


            from Nethuch Mahalingam Added 26 0 0

            This video was completed for the 2015 Peel Technological Skills Challenge, under the category of TV and Video Production (Secondary Level). Our assignment was to film a 30-second long PSA on the topic of "Cyberbullying" and we had around 5 hours to shoot and edit. We were competing against 13 different teams from high schools across Peel District and we managed to win Gold (1st Place).

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