ABSTRACT
Sub-metered energy use of an in-slab gas hydronic heating system and a newly installed split system air conditioner in thermodynamically-equivalent classrooms are compared during unoccupied (with artificially imposed internal heat gains) and occupied periods. A preliminary comparison is also undertaken to quantify the heating penalty for the existing gas-fuelled hydronic heating systems when windows remain open (e.g. to comply with COVID-19 guidelines in schools) against the energy needed for heating by the same system in a control classroom with windows closed. The performance evaluation of the heating systems during three unoccupied days where internal heat gains were artificially imposed demonstrated that the gas hydronic system used 41.5 kWh of metered energy while the AC split system used 7.2 kWh, with the AC split system being able to maintain the internal conditions above the set point by operating for approximately one third of the time the hydronic system was operating. Occupied tests confirmed the observations of the unoccupied tests of equivalent operation. Over a period of 2 occupied winter weeks, the in-slab gas hydronic heating system used 274.6 kWh of metered energy and operated for 35¼ hrs, while the AC split system used 34.7 kWh and operated for 22¼ hrs, albeit on some occasions the occupants in the AC split system’s classroom chose not to turn on the system. After selecting days from this occupied period when both systems were used for long periods, it was observed that the AC split system used approximately 4 to 7 times less metered energy than the in-slab gas hydronic system (or 3.3 times in terms of primary energy when worse-case primary energy factors were used). Finally, from the preliminary test, the parallel measurements also confirmed that the additional ventilation in schools through opening of windows increases the energy use of the hydronic heating system;66.8 kWh were measured for heating needs over a period of 3-days as opposed to 25 kWh for the windows open and closed cases respectively. These precise values are, however dependent on the season and building type.
ABSTRACT
Medical professionals often deny patients who inject opioids a second or third heart valve replacement, even if such a surgery is medically indicated. However, such a position is not well defended. As this paper demonstrates, the ethical literature on the topic too often fails to develop and apply an ethical lens to analyse the issue of multiple valve replacements. This paper addresses this lacuna by analysing the case of Mr Walsh, a composite case which protects the identity of any one patient, through the principlist approach of Beauchamp and Childress. It argues that the hospital should offer Mr Walsh, a second valve replacement because the procedure is: medically indicated, autonomously requested, non-maleficent, beneficent and does not violate a formal account of justice. The paper concludes with clinical ethical guidelines for valve surgery for patients with opioid use disorder.
ABSTRACT
Management options for common bile duct stones found at laparoscopic cholecystectomy (LC) includes concurrent transcystic biliary stenting, effectively providing a conduit for common bile duct drainage and improving the success of subsequent endoscopic retrograde cholangiopancreatography. In the unprecedented COVID-19 pandemic however, potential disruptions to the medical supply chain have been far reaching, including the distribution of specialised biliary stent sets. To overcome this, we devised an innovative method at our centre to substitute traditional procedural stent sets by employing standard, universally accessible open-ended ureteral catheters, jagwires and pancreatic or biliary stents with similar procedural success.