The future of space exploration: the next 50 years

This repository item contains a single issue of Issues in Brief, a series of policy briefs that began publishing in 2008 by the Boston University Frederick S. Pardee Center for the Study of the Longer-Range Future.This policy brief flows from the 2007 Pardee Center conference on The Future of Space and lays out a set fo critical challenges for the next 50 years of space explorations

On the importance of the cross-body approach in planetary aeronomy

Cross-disciplinary and cross-body approaches can be applied to study universal processes occurring in the heliosphere. Magnetospheric, interplanetary, and heliospheric plasmas, all of which are low density plasmas, host similar processes. A cross-disciplinary approach is thus of great relevance for a universal understanding of processes occurring within these various plasmas. On the other hand, the upper atmosphere of planets and moons are a highly collisional medium acting differently compared to a collisionless plasma. Therefore, the comparative study between solar system bodies hosting atmospheres under different settings is a more suitable approach for assessing universal processes in aeronomy. For the past several years the aeronomy community has undertaken many initiatives in comparative studies of solar system atmospheres. We highlight the maturity of this field and illustrate its relevance by applying the comparative approach to key scientific topics. We would like to encourage aeronomers interested in comparative studies to consider participating to International Heliophysical Year (IHY) focused activities. More information on the comparative initiative can be found at the IHY website (http://ihy.gsfc.nasa.gov/) as well as at: http://www.bu.edu/csp/uv/ cp-aeronomy/aeronomy-sol-sys.html

Functionalized Carbon Nanotube and MnO2 Nanoflower Hybrid as an Electrode Material for Supercapacitor Application

Functionalized carbon nanotube (FCNT) and Manganese Oxide (MnO2) nanoflower hybrid material was synthesized using hydrothermal technique as a promising electrode material for supercapacitor applications. The morphological investigation revealed the formation of ‘nanoflower’ like structure of MnO2 connected with FCNT, thus paving an easy path for the conduction of electrons during the electrochemical mechanism. A significant improvement in capacitance properties was observed in the hybrid material, in which carbon nanotube acts as a conducting cylindrical path, while the major role of MnO2 was to store the charge, acting as an electrolyte reservoir leading to an overall improved electrochemical performance. The full cell electrochemical analysis of FCNT-MnO2 hybrid using 3 M potassium hydroxide (KOH) electrolyte indicated a specific capacitance of 359.53 F g−1, specific energy of 49.93 Wh kg−1 and maximum specific power of 898.84 W kg−1 at 5 mV s−1. The results show promise for the future of supercapacitor development based on hybrid electrode materials, where high specific energy can be achieved along with high specific power and long cycle life

Thermo-optical characterization of novel MXene/Carbon-dot hybrid nanofluid for heat transfer applications

Nanofluid has emerged as a promising heat transfer fluid (HTF) due to their significant thermophysical, and optical characteristics enhancement over base fluids. Hybrid nanofluids with multiple nanomaterials have the advantage of synergistic properties in comparison to monocomponent nanofluids. The present study proposes an energy-efficient and cleaner synthesis method for developing carbon quantum dot (C-dot), MXene, and a hybrid MXene/C-dot hybrid nanofluids, for heat transfer application. In-situ microwave pyrolysis technique and two-step method were adopted for nanomaterial and nanofluid synthesis. The morphological, phase structural, chemical, and elemental compositional analysis of the nanomaterials was performed. The material characterization confirms the hybridization of C-dot on MXene nanosheets. The thermal conductivity and volumetric heat capacity of the nanofluids were measured using the transient plane source (TPS) method. Thermal conductivity was observed to increase with nanofluid concentration and temperature. Results indicate that MXene has the highest thermal conductivity enhancement (50 %) over water, followed by hybrid (42.2 %) and C-dot nanofluid (33.2 %). The volumetric heat capacity of nanofluids decreased with concentration and temperature. A semi-empirical correlation, as a function of nanofluid concentration and temperature, was coined for predicting thermal conductivity and volumetric heat capacity. Optical property characterization study shows that C-dot nanofluid exhibited considerable absorption along the UV range, while MXene nanofluid showed absorption in the visible and near-infrared (NIR) region. Hybrid nanofluids demonstrated complementary absorption properties of C-dot and MXene nanofluids