Effect of gamma radiation on sealing capacity characteristics of three commercially available nitrile rubber samples compared against an industrial seal used in AGR power plants

The maintenance of the Fuelling Machine operating in an AGR reactor consumes a large number of working hours and operational budget. As part of an optimisation programme research work is currently being carried out to investigate the degradation mechanism on the dynamic seal on one of these machines. The aim of this work is to understand seal behaviour under reactor working conditions in a bid to develop a mechanistic understanding of its long-term degradation and optimise the component’s maintenance schedule. The deleterious operational conditions have been identified as; activation of the sealing face through compression, exposure to a low radiation dose and cycle exposure to pressurised carbon dioxide. This part of the work investigates the effect of radiation damage on the CO2 uptake and swelling behaviour, mechanical properties and physical and chemical structure of three commercially available nitrile rubber samples which are then compared against the characteristics for the chosen seal. Exposure to radiation resulted in increased mechanical strength and resilience of the rubber as well as decreased CO2 loading capacity and swelling, further supporting the theory of cross-link formation. The seal was more resistant to the effects of radiation than the three nitrile rubber samples, however scanning electron microscopy identified the initiation and propagation of cracks without any external stress applied on the irradiated samples, the result of in-built stresses created during the manufacturing process. The next stage of this work will investigate the effect of the local environment on the radiation-induced changes in the sample’s ultimate sealing capacity

The management of diabetic ketoacidosis in children

The object of this review is to provide the definitions, frequency, risk factors, pathophysiology, diagnostic considerations, and management recommendations for diabetic ketoacidosis (DKA) in children and adolescents, and to convey current knowledge of the causes of permanent disability or mortality from complications of DKA or its management, particularly the most common complication, cerebral edema (CE). DKA frequency at the time of diagnosis of pediatric diabetes is 10%–70%, varying with the availability of healthcare and the incidence of type 1 diabetes (T1D) in the community. Recurrent DKA rates are also dependent on medical services and socioeconomic circumstances. Management should be in centers with experience and where vital signs, neurologic status, and biochemistry can be monitored with sufficient frequency to prevent complications or, in the case of CE, to intervene rapidly with mannitol or hypertonic saline infusion. Fluid infusion should precede insulin administration (0.1 U/kg/h) by 1–2 hours; an initial bolus of 10–20 mL/kg 0.9% saline is followed by 0.45% saline calculated to supply maintenance and replace 5%–10% dehydration. Potassium (K) must be replaced early and sufficiently. Bicarbonate administration is contraindicated. The prevention of DKA at onset of diabetes requires an informed community and high index of suspicion; prevention of recurrent DKA, which is almost always due to insulin omission, necessitates a committed team effort

Low Rates of 30-Day Postoperative Complications After Meniscal Allograft Transplantation: A Retrospective Study Using the National Surgical Quality Improvement Program Database

Purpose: To determine the short-term (30-day) postoperative complication rates in patients undergoing meniscus allograft transplantation (MAT). Methods: The American College of Surgeons National Surgical Quality Improvement Program database was queried for patients who had undergone MAT from 2014 to 2021 using Current Procedural Terminology codes. Patients were excluded if they did not have sufficient demographic data, namely those without data for age, sex, body mass index, preoperative functional status, American Society of Anesthesiologists classification, operative time, and length of hospital stay. Postoperative complications within 30 days were identified, and rates of complications were examined as the primary outcome of this study. As a secondary outcome, multivariate logistic regression was used to identify risk factors associated with the 30-day incidence of postoperative complications. Subgroup analysis was performed to analyze differences in postoperative outcomes after isolated MAT versus MAT with concomitant ligament reconstruction/repair, cartilage preservation, or realignment osteotomy. Results: A total of 396 meniscal transplants were identified, with mean age of 35.2 ± 14.9, mean body mass index of 29.6 ± 6.7, mean length of stay of 0.5 ± 1.8 days. Eleven patients experienced any adverse event. Specific complications included surgical-site infections (5), deep-vein thrombosis (1), urinary tract infection (3), and return to the operating room (2). On subgroup analysis, there was no significant difference between any adverse event rates in patients undergoing MAT with concomitant procedures compared with patients undergoing isolated MAT (7 vs 4, P = .5). Conclusions: Patients who underwent MAT had an overall complication rate of 2.8% in the short-term postoperative period (≤30 days). Patients undergoing MAT with concomitant ligament reconstruction/repair, cartilage preservation, and realignment osteotomy had similar rates of all postoperative complications when compared with patients undergoing isolated MAT. Level of Evidence: Level IV, therapeutic case series

7-14 GHz Optical Phase-Locked Loop (OPLL) Source Module for Use in Coherent Optical Beamforming Applications

The first reported optical phase-locked loop module has been designed and constructed for use in coherent optical beamforming systems. It has been implemented using micro-optics, wideband feedback electronics and custom diode lasers with a suitable FM response. The module has an LO tuning range of 7-14 GHz and a total phase error variance of 0.05 rad(2)

Optical Phase Locked Loop (OPLL) Module for Use as a 9 GHz Source in Phased Array Communications Antennas

A packaged diode-laser optical phase locked loop (OPLL) sub-system is constructed for evaluation in an proof-of-concept optical beamforming system. The loop is implemented with laser diodes, micro-optics and linewidth, wide bandwidth electronics to give optimum phase noise performance. The laser diodes are designed for narrow linewidth, wide bandwidth and high FM-efficiency, whilst the main challenge in the construction of the packaged OPLL is the realization of a high gain loop, with a small propagation delay