Synthesis and characterization of polystyrene carbon nanotube nanocomposite for utilization in the displaced foam dispersion methodology

Incorporating nanostructured functional constituents within polymers has become extensive in processes and products for manufacturing composites. The conception of carbon nanotubes (CNTs) and their heralded attributes that yield property enhancements to the carrier system is leading many industries and research endeavors. Reported Displaced Foam Dispersion (DFD) methodology is a novel and effective approach to facilitating the incorporation of CNTs within fiber reinforced polymer composites (FRPC). The methodology consists of six separate solubility phases that lead to the manufacture of CNT-FRPCs. This study was primarily initiated to characterize the interaction parameters of nanomaterials (multiwalled carbon nanotubes), polymers (polystyrene), and solvents (dimethyl formamide (DMF) and acetone) in the current paradigm of the DFD materials manufacture. Secondly we sought to illustrate the theoretical potential for the methodology to be used in conjunction with other nanomaterial-polymer-solvent systems. Herein, the theory of Hansen\u27s solubility parameters (HSP) is employed to explain the effectiveness of the DFD materials manufacture ratios and aid in the explanation of the experimental results. The results illustrate quantitative values for the relative energy differences between each polymer-solvent system. Transmission electron microscopy (TEM) was used to characterize the multiwalled carbon nanotubes (MWCNTs) in each of the solubility stages and culminates with an indication of good dispersion. Additionally, the rate of acetone evaporation over 25 min is reported for the sorbed CNTaffy nanocomposites from 0 to approximately 60 wt percent loadings

Recreating the California New Year's Flood Event of 1997 in a Regionally Refined Earth System Model

Abstract: The 1997 New Year's flood event was the most costly in California's history. This compound extreme event was driven by a category 5 atmospheric river that led to widespread snowmelt. Extreme precipitation, snowmelt, and saturated soils produced heavy runoff causing widespread inundation in the Sacramento Valley. This study recreates the 1997 flood using the Regionally Refined Mesh capabilities of the Energy Exascale Earth System Model (RRM‐E3SM) under prescribed ocean conditions. Understanding the processes causing extreme events informs practical efforts to anticipate and prepare for such events in the future, and also provides a rich context to evaluate model skill in representing extremes. Three California‐focused RRM grids, with horizontal resolution refinement of 14 km down to 3.5 km, and six forecast lead times, 28 December 1996 at 00Z through 30 December 1996 at 12Z, are assessed for their ability to recreate the 1997 flood. Planetary to synoptic scale atmospheric circulations and integrated vapor transport are weakly influenced by horizontal resolution refinement over California. Topography and mesoscale circulations, such as the Sierra barrier jet, are better represented at finer horizontal resolutions resulting in better estimates of storm total precipitation and storm duration snowpack changes. Traditional time‐series and causal analysis frameworks are used to examine runoff sensitivities state‐wide and above major reservoirs. These frameworks show that horizontal resolution plays a more prominent role in shaping reservoir inflows, namely the magnitude and time‐series shape, than forecast lead time, 2‐to‐4 days prior to the 1997 flood onset

Recreating the California New Year's Flood Event of 1997 in a Regionally Refined Earth System Model

Abstract The 1997 New Year's flood event was the most costly in California's history. This compound extreme event was driven by a category 5 atmospheric river that led to widespread snowmelt. Extreme precipitation, snowmelt, and saturated soils produced heavy runoff causing widespread inundation in the Sacramento Valley. This study recreates the 1997 flood using the Regionally Refined Mesh capabilities of the Energy Exascale Earth System Model (RRM‐E3SM) under prescribed ocean conditions. Understanding the processes causing extreme events informs practical efforts to anticipate and prepare for such events in the future, and also provides a rich context to evaluate model skill in representing extremes. Three California‐focused RRM grids, with horizontal resolution refinement of 14 km down to 3.5 km, and six forecast lead times, 28 December 1996 at 00Z through 30 December 1996 at 12Z, are assessed for their ability to recreate the 1997 flood. Planetary to synoptic scale atmospheric circulations and integrated vapor transport are weakly influenced by horizontal resolution refinement over California. Topography and mesoscale circulations, such as the Sierra barrier jet, are better represented at finer horizontal resolutions resulting in better estimates of storm total precipitation and storm duration snowpack changes. Traditional time‐series and causal analysis frameworks are used to examine runoff sensitivities state‐wide and above major reservoirs. These frameworks show that horizontal resolution plays a more prominent role in shaping reservoir inflows, namely the magnitude and time‐series shape, than forecast lead time, 2‐to‐4 days prior to the 1997 flood onset