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The green propellant hydroxylammonium nitrate (HAN) is a good alternative to the conventional propellants in space propulsion applications because of its low toxicity and high energy density. Electrolytic decomposition and ignition of HAN solution, an ionic liquid, is a promising approach. In this work, comprehensive experimental studies were conducted to examine effects of different electrolytic voltages, electrode surface areas, and HAN concentrations on the decomposition process. In the test cases, an optimum electrolytic voltage appears to exist, which leads to the fastest decomposition process. As the voltage increases, a larger electrode surface area on the anode side should be used to overcome an anodic inhibition phenomenon and accelerate the electrolytic process. A high concentration of HAN solution is preferred for its decomposition and ignition. Results also reveal that the electrolytic process of a HAN solution could eventually trigger thermal decomposition reactions, raising the maximum temperature to around 550 K at the final stage. A detailed chemical reaction mechanism was proposed, based on the experimental data and FTIR spectra analyses. Results obtained herein would provide fundamental understandings on the complex electrochemical and physical processes and should be helpful for future applications of the electrolytic decomposition and ignition technology.

The conventional laparoscopic cholecystectomy (CLC) is usually performed with four incisions in a simple and safe way. Minimally invasive surgery for gallbladder disease with advantages of less pain and smaller scars, has become increasingly popular in patients. This study aimed to describe our experience in performing a new technique of two-incision laparoscopic cholecystectomy (TILC) with conventional instruments and make a comparison with CLC. In this study, forty-three prospective patients undergoing TILC and another forty-three historical cases operated by CLC were involved. The patients were examined in respect of operative time, postoperative pain, cosmesis and complications. We found that there was no significant difference in the gender, age, body mass index, bile duct damage, blood loss and days of postoperative hospital stay between TILC and CLC. The mean operation time in TILC was longer than that in CLC, but not statistically different. Significantly lower postoperative pain scores were reported in the TILC group than those in the CLC one (p = 0.019). The mean cosmetic satisfaction score was significantly higher in TILC group than that in CLC group (p < 0.05). These results confirm that TILC is a safe and feasible technique with less postoperative pain and a significant improvement in cosmesis for patients, only by using conventional instruments. It may be a good alternative to CLC in the future.