The need for renewable fiber reinforced composites has never been as prevalent as it currently is. Natural fibers offer both cost savings and a reduction in density when compared to glass fibers. Though the strength of natural fibers is not as great as glass, the specific properties are comparable. Currently natural fiber composites have two issues that need to be addressed: resin compatibility and water absorption. The following preliminary research has investigated the use of Kenaf, Hibiscus cannabinus, as a possible glass replacement in fiber reinforced composites.

Metal hydrides can be utilized for hydrogen storage and for thermal energy storage (TES) applications. By using TES with solar technologies, heat can be stored from sun energy to be used later, which enables continuous power generation. We are developing a TES technology based on a dual-bed metal hydride system, which has a high-temperature (HT) metal hydride operating reversibly at 600-800 °C to generate heat, as well as a low-temperature (LT) hydride near room temperature that is used for hydrogen storage during sun hours until there is the need to produce electricity, such as during night time, a cloudy day or during peak hours. We proceeded from selecting a high-energy density HT-hydride based on performance characterization on gram-sized samples scaled up to kilogram quantities with retained performance. COMSOL Multiphysics was used to make performance predictions for cylindrical hydride beds with varying diameters and thermal conductivities. Based on experimental and modeling results, a ~200-kWh/m 3 bench-scale prototype was designed and fabricated, and we demonstrated the ability to meet or exceed all performance targets. OPEN ACCESSEnergies 2015, 8 8407

Executive SummaryThe motivation for this study stems from the need to address the aging management of incontainment cables at nuclear power plants (NPPs). The most important criterion for cable performance is its ability to withstand a design-basis accident. With nearly 1000 km of power, control, instrumentation, and other cables typically found in a NPP, it would be a significant undertaking to inspect all of the cables. Degradation of the cable jacket, electrical insulation, and other cable components is a key issue that is likely to affect the ability of the currently installed cables to operate safely and reliably for another 20 to 40 years beyond the initial operating life. The development of one or more nondestructive evaluation (NDE) techniques and supporting models that could assist in determining the remaining life expectancy of cables or their current degradation state would be of significant interest. The ability to nondestructively determine material and electrical properties of cable jackets and insulation without disturbing the cables or connections has been deemed essential.Currently, the only technique accepted by industry to measure cable elasticity (the gold standard for determining cable insulation degradation) is the indentation measurement. All other NDE techniques are used to find flaws in the cable and do not provide information to determine the current health or life expectancy.There is no single NDE technique that can satisfy all of the requirements needed for making a lifeexpectancy determination, but a wide range of methods have been evaluated for use in NPPs as part of a continuous evaluation program. The commonly used methods are indentation and visual inspection, but these are only suitable for easily accessible cables. Several NDE methodologies using electrical techniques are in use today for flaw detection but there are none that can predict the life of a cable.There are, however, several physical and chemical property changes in cable insulation as a result of thermal and radiation damage. In principle, these properties may be targets for advanced NDE methods to provide early warning of aging and degradation. Examples of such key indicators include changes in chemical structure, mechanical modulus, and dielectric permittivity. While some of these indicators are the basis of currently used technologies, there is a need to increase the volume of cable that may be inspected with a single measurement, and if possible, to develop techniques for in-situ inspection (i.e., while the cable is in operation). This is the focus of the present report.Several approaches to nondestructively measuring key indicators of cable aging and degradation may be available, and could include chemical, mechanical, and electrical measurements. Electrical and acoustic measurements are potential alternative NDE approaches that may be capable of providing in-situ assessments of cable condition and remaining useful life.Measurement studies were conducted with samples of aged ethylene propylene rubber (EPR) cabl...

SUMMARYThe Fuel Cycle Research and Development Program, sponsored by the U.S. Department of Energy Office of Nuclear Energy, is currently investigating alternative waste forms for wastes generated from the reprocessing of nuclear fuel. One such waste results from an electrochemical separations process, called the "Echem" process, in molten KCl-LiCl salt as a spent salt containing alkali, alkaline earth, lanthanide halides and a small quantities of actinide halides where the primary anion is chloride with small quantities of iodide. Pacific Northwest National Laboratory (PNNL) is investigating two candidate waste forms for the Echem spent-salt, high-halide minerals (i.e., sodalite and cancrinite) and tellurite (TeO 2 )-based glasses. Both of these candidates showed promise in FY2009 and FY2010 with a simplified nonradioactive simulant of the Echem waste. Further testing was performed on these waste forms in the fiscal (FY) and calendar (CY) year of 2011 to investigate the possibility of their use in a sustainable fuel cycle. This report summarizes the results of FY/CY2011 efforts.The chemical durability results for the tellurite glasses in FY2010 revealed a wide variety of waste form performance in these materials. The most promising glass studied was a lead-tellurite glass formulation with the Echem salt simulant. This glass showed very good chemical durability with a normalized release for sodium of 0.478 g/m 2 following a seven-day leaching test. With this in mind, the following studies were undertaken in FY/CY2011 to further investigate and optimize this type of glass as a potential waste form: 1) Expanded study on lead-tellurite glasses. The lead-tellurite glass system was further investigated in FY/CY2011 to determine the waste-loading limits and assess the tellurium-oxygen bonding structure as a function of waste loading with Raman spectroscopy and X-ray diffraction. Te-O bonding in tellurite glasses is quite complex; at least eight different structures have been presented in the literature and typically include α-TeO 4 , β-TeO 4 , TeO 3+1 , and TeO 3 structures (the α/β notation denotes the way that the TeO 4 species bond to one another, and the number after the "O" denotes the number of oxygens bonded to the central Te atom in that species). We also investigated some of the other waste-form related properties of the lead-tellurite glasses, such as the thermal diffusivity, glass transition temperature, crystallization temperature, melting temperature, and mass loss as a function of temperature. The structural investigation revealed that the medium-range order in the glass decreased and the tellurite network was depolymerized as the waste fraction was increased. It was apparent that glass-network breaking was predominantly caused by the additions of the waste cations and that the presence of chloride may have actually caused some repolymerization of the network by scavenging alkali and preventing it from acting as a network modifier. At the highest waste loadings, the glass became phaseseparated, resulting...

Among candidates for chemical hydrogen storage in PEM fuel cell automotive applications, ammonia borane (AB, NH 3 BH 3 ) is considered to be one of the most promising materials due to its high hydrogen content of 14−16 wt % and high volumetric density of ∼146 g H 2 /liter. To utilize the existing infrastructure, a fluid-phase hydrogen storage material is attractive, and thus, we investigated the materials' properties of AB in liquid carriers for a chemical hydrogen storage slurry system. Slurries composed of AB and high-boiling-point liquids were prepared by mechanical milling and sonication in order to obtain stable and fluidic properties. Kinetics of the H 2 release reactions of the AB slurry and neat AB was studied using a volumetric gas buret. Viscometry and microscopy were employed to further characterize the engineering properties of the slurries. Using a tipsonication method, we have produced AB/silicone fluid slurries at solid loadings up to 40 wt % (6.5 wt % H 2 ) with viscosities less than 500 cP at 25 °C.