Passive Thermal Storage of Small Satellites for SWaP Improvements Over Thousands of Operational Cycles

Satellite manufacturers and customers continue to trend toward higher power, duty cycle-driven components (high powered amplifiers) to get the most capability out of each small/CubeSat put in orbit. The result is more waste heat to manage, requiring engineers to develop a means of transferring or storing the energy without causing a substantial increase in thermal management system mass. Phase Change Material (PCM) heat sinks are being utilized by the industry as a solution to this challenge due to their fully passive operation and ability to reduce the mass of the thermal management system. PCM heat sinks for duty cycle applications are intended to absorb waste heat during operation, then utilize the dormant period of the orbit to fully dissipate the energy stored. This time-averaged dissipation allows the radiator panel to be designed for the average heat load rather than the peak value, resulting in significant surface area reduction in most applications. PCM heat sinks can also reduce the magnitude of temperature cycles, which can also reduce the severity of solder/bond line stresses that may accumulate as fatigue damage during cyclic operation. The construction of PCM heat sinks typically employ an aluminum enclosure with an internal conductivity enhancing (fin/foam/lattice) structure with the PCM encapsulated within. The internal conductivity-enhancing structure design of the heat sink and PCM selection must be optimized together to enable high performance, as the PCM material has relatively low thermal conductivity. Furthermore, because the PCM is chosen specifically for its material properties, it is imperative that the PCM retains these properties throughout the repeated melt/solidify cycles that it will experience during use. This is especially true for satellite and space applications where the PCM may see thousands of cycles due to orbital operational profiles. As such, designers in these markets must also focus on qualification of the design across long time periods with many cycles. Long term stability of common paraffin wax (or alkanes PCMs have been verified experimentally) through thousands of operational cycles. Two common hydrocarbon PCMs, Octadecane and Eicosane, have been subjected to over 10,000 phase change cycles and the results are presented here

Self-Optimising Reactive Extractions: Towards the Efficient Development of Multi-Step Continuous Flow Processes

Downstream purification of products and intermediates is essential for the development of continuous flow processes. Described herein, is a study on the use of a modular and reconfigurable continuous flow platform for the self-optimisation of reactive extractions and multi-step reaction-extraction processes. The selective extraction of one amine from a mixture of two similar amines was achieved with an optimum separation of 90%, and in this case, the black-box optimisation approach was superior to global polynomial modelling. Furthermore, this methodology was utilised to simultaneously optimise the continuous flow synthesis and work-up of N-benzyl-α-methylbenzylamine with respect to four variables, resulting in a significantly improved purity

Selective Separation of Amines from Continuous Processes using Automated pH Controlled Extraction

We present a rapid continuous processing methodology to screen for the optimal, selective, liquid-liquid extraction conditions, from a typical post-reaction mixture of amines, using both inline and online analysis to systematically alter the pH, by controlling the acid addition pump. A mixture of 95% α-methyl-benzylamine, 1, and 5% N-benzyl-α-methyl-benzylamine, 2, simulated a reaction product and impurity, with the former extracted from toluene into water with 92% efficiency and 99% purity. The initial acid concentration and outlet pH (post-extraction), were compared with the amine concentration in each phase. The incorporation of inline, pH and HPLC, monitoring of both the aqueous and organic phases, allowed for detailed analysis of the applied extraction conditions. This produced an autonomous system for exploring the amine extraction conditions: optimal amount of acid and organic-aqueous phase ratio

Common variation at 3q26.2, 6p21.33, 17p11.2 and 22q13.1 influences multiple myeloma risk

To identify variants for multiple myeloma risk, we conducted a genome-wide association study with validation in additional series totaling 4,692 individuals with multiple myeloma (cases) and 10,990 controls. We identified four risk loci at 3q26.2 (rs10936599, P = 8.70 × 10-14), 6p21.33 (rs2285803, PSORS1C2, P = 9.67 × 10-11), 17p11.2 (rs4273077, TNFRSF13B, P = 7.67 × 10-9) and 22q13.1 (rs877529, CBX7, P = 7.63 × 10-16). These data provide further evidence for genetic susceptibility to this B-cell hematological malignancy, as well as insight into the biological basis of predisposition.<br/