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Case: Although many complications have been reported with intrauterine contraceptive devices (IUDs), vesicovaginal fistula with secondary vaginal stones is rare. We report the case of a 46-year-old woman who presented with a vaginal discharge lasting 2 months. Two years previously, she had undergone cystoscopic lithotripsy and surgery to remove an IUD, after pelvic radiography had revealed a fractured Chinese stainless steel ring IUD with secondary vesical stones that had been the cause of her urinary tract symptoms. When she again complained of vaginal discharge, vaginal stones and a vesicovaginal fistula were found on physical examination and CT urography. The patient underwent stone removal and concurrent vesicovaginal fistula repair. IUD fragments were found in the vesicovaginal and rectovaginal spaces. No abnormalities were found at follow-up 6 months after surgery.Conclusion: In any woman undergoing surgery to remove a migrated IUD, complete exposure and removal of the IUD are necessary to avoid fracturing of the IUD, secondary breakage and residue. [ABSTRACT FROM AUTHOR] more...

This article presents an experimental investigation on the subcooled flow boiling heat transfer characteristics of CO2 in a horizontal tube with inner diameter of 6.16 mm below -30°C. The effects of mass and heat fluxes and saturation temperature on the heat transfer coefficient are discussed. Large deviations are noted between the predictions from previous empirical correlations and the current CO2 experimental data. Hence a new empirical correlation is developed, which agrees within ±30% with the current CO2 experimental data. It is expected that the data presented in this study would be beneficial to industry and designers of compact heat exchangers for CO2 at low temperatures. [ABSTRACT FROM AUTHOR] more...

There is a growing use of CO2 refrigeration to achieve low temperatures, particularly in the food industry; however, very limited information is available in the open literature on its boiling heat transfer characteristics below -30°C. This paper investigates experimentally the flow boiling heat transfer of CO2 at low temperatures down to -40°C. The experimental data were collected from a novel experimental rig, specifically designed to achieve low temperatures, using a 4.5 m long horizontal stainless steel tube of 4.57 mm inner diameter. The effects of heat and mass fluxes and saturation temperature on the flow boiling heat transfer coefficient are also analyzed. Furthermore, this paper highlights the limitations of existing empirical correlations by comparing their predictions with the experimental boiling heat transfer coefficients. It is expected that the data presented in this study would be beneficial to industry and designers of compact heat exchangers for CO2 at low temperatures. [ABSTRACT FROM AUTHOR] more...