Modal Nodal Transport Analysis

Johnson, R.Douglas Korean Nuclear Society 1971 Nuclear Engineering and Technology Vol.3 No.3

A unified modal-nodal expansion of tile angular distribution of neutron flux in one spatial dimension is considered, following the proposal of Harms. Several standard nodal and/or modal methods of analysis are shown to be specializations of this technique. The modal-nodal moment from of the mono-energetic transport equation with isotropic sources and scattering is derived and the infinite medium eigenvalue problem solved. The technique is shown to yield results which approximate the exact value of the inverse diffusion length in non-multiplying media more accurately than standard methods of equal or somewhat greater computational complexity.

Deposition efficiency of barium hexaferrite by aerosol deposition

Johnson, Scooter D.,Schwer, Douglas,Park, Dong-Soo,Park, Yoon-Soo,Gorzkowski, Edward P. Elsevier 2017 Surface & coatings technology Vol.332 No.-

<P><B>Abstract</B></P> <P>We present results of barium hexaferrite powder mass consumption across a wide range of starting powder quantities and deposition times. From these results we develop a transfer efficiency figure of merit to describe deposition efficiency and growth rates applicable to aerosol deposition and similar spray deposition techniques. We find that the transfer efficiency of barium hexaferrite was 0.082% and the transfer efficiency rate coefficient was 0.056min<SUP> −1</SUP> with a decay factor of −0.773. As a means to further understanding the deposition efficiency we present flow simulations of an aerosol deposition system using different particle sizes and standoff distances. We find that impact with the substrate strongly depends on the particle size, particle location within the nozzle, and standoff distance. We find that the values in the simulation are consistent with those used to produce films with the aerosol deposition system used at the Naval Research Laboratory and consistent with values found in the literature. We find that to improve the transfer efficiency nozzle design must be optimized, particle size must be carefully selected, standoff distance must be selected, and the powder in the aerosol chamber must be delivered at an optimal rate. These factors may be individually tuned to contribute to the final transfer efficiency figure of merit that can be used to assess the efficiency of the aerosol deposition process.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Mass consumption of powder in aerosol deposition is related to film thickness. </LI> <LI> A deposition efficiency figure of merit is developed for aerosol deposition. </LI> <LI> Fluid dynamic simulations show that particle impact depends on particle size. </LI> <LI> Fluid dynamic simulations show that particle impact depends on standoff distance. </LI> <LI> Deposition efficiency is related to mass consumption and to particle impact. </LI> </UL> </P>

Slide Session : OS-END-47 ; Endocrinology : Denosumab-Associated Hypocalcaemia: Incidence, Se-verity and Patient Characteristics in a Tertiary Hospital Setting

( Andrew Huynh ),( Scott Baker ),( Andrew Stewardson ),( Douglas Johnson ) 대한내과학회 2014 대한내과학회 추계학술대회 Vol.2014 No.1

Background: Denosumab, a humanised monoclonal antibody against receptor activator of nuclear factor kappa beta ligand (RANKL), reduces bone turnover via inhibition of osteoclasts and osteoclastogenesis and is used in the management of osteoporosis and metastatic bone disease. While hypocalcaemia complicating denosumab treatment has been reported, the real world incidence, clinical and biochemical risk factors are not fully elucidated. This study aims to investigate the incidence of denosumab-associated hypocalcaemia (DAH) and identify relevant clinical and investigation features. Methods: We performed a retrospective observational audit of patients administered denosumab (60mg/120mg) over a 12 month period at a tertiary hospital in Australia. Data collected: denosumab dosage and indication, 25-hydroxyvitamin D concentration, parathyroid hormone, estimated glomerular filtration rate (eGFR), nadir and duration of hypocalcaemia (albumin adjusted serum calcium concentration <2.15 mmol/L or ionised calcium <1.13 mmol/L upto 6 months post denosumab administration), calcium and colecalciferol pre- and post-administration of denosumab. The primary outcome was the incidence proportion of DAH. Results: Of 161 patients administered denosumab (106 osteoporosis, 55 bone metastases), 20 patients (12.4%, mean age 78.5 years, 11 male, 11 osteoporosis, 9 bone metastases) developed hypocalcaemia. Median calcium nadir was 2.06 mmol/L (interquartile range (IQR) 1.81-2.11), with the median time to diagnosis 24.50 days (IQR 9.25-41.25). One patient required intravenous calcium gluconate treatment. 75% of affected patients had a 25-hydroxyvitamin D concentration >50nmol/L and 90% of affected patients were on calcium or colecalciferol supplementation. DAH was associated with sex (27% males versus 8% females, p=0.004), but not age (8% under 60 years versus 13% aged 60 or more, p=0.74) or indication (16% with bone metastases versus 10% with osteoporosis, p=0.32). Conclusions: Denosumab-associated hypocalcaemia occurred in over 12% of patients in this population, despite wide use of appropriate calcium and colecalciferol supplementation.

A comparison of the breathing apparatus deadspace associated with a supraglottic airway and endotracheal tube using volumetric capnography in young children

Goenaga-Diaz Eduardo Javier,Smith Lauren Daniela,Pecorella Shelly Harrell,Smith Timothy Earl,Russell Gregory B,Johnson Kathleen Nicole,Downard Martina Gomez,Ririe Douglas Gordon,Hammon Dudley Elliott 대한마취통증의학회 2021 Korean Journal of Anesthesiology Vol.74 No.3

Background: Supraglottic airway (SGA) devices including the air-Q® are being used with increasing frequency for anesthesia in infants and younger pediatric patients. To date, there is minimal research documenting the potentially significant airway deadspace these devices may contribute to the ventilation circuit when compared to an endotracheal tube (ETT). The aim of this study was to evaluate the airway apparatus deadspace associated with an air-Q® versus an ETT in young children.Methods: In a prospective cohort study, 59 patients between 3 months and 6 years of age, weighing between 5 and 20 kg, scheduled for outpatient urologic or general surgery procedures were recruited. An air-Q® or ETT was inserted at the discretion of the attending anesthesiologist, and tidal volume, positive end expiratory pressure, respiratory rate, and end-tidal CO2 were controlled according to protocol. Airway deadspace was recorded using volumetric capnography every 2 min for 10 min. Results: Groups were similar in demographics. There was a significant difference in weight-adjusted deadspace volume between the air-Q® and ETT groups, 4.1 ± 0.8 ml/kg versus 3.0 ± 0.7 ml/kg, respectively (P < 0.001). Weight-adjusted deadspace volume (ml/kg) increased significantly with decreasing weight for both the air-Q® and ETT groups.Conclusions: In healthy children undergoing positive pressure ventilation for elective surgery, the air-Q® SGA introduces significantly greater airway deadspace than an ETT. Additionally, airway deadspace, and minute ventilation required to maintain normocarbia, appear to increase with decreasing patient weight irrespective of whether a SGA or ETT is used.

Prediction of Survival by [¹⁸F]Fluorodeoxyglucose Positron Emission Tomography in Patients With Locally Advanced Non–Small-Cell Lung Cancer Undergoing Definitive Chemoradiation Therapy: Results of the ACRIN 6668/RTOG 0235 Trial

Machtay, Mitchell,Duan, Fenghai,Siegel, Barry A.,Snyder, Bradley S.,Gorelick, Jeremy J.,Reddin, Janet S.,Munden, Reginald,Johnson, Douglas W.,Wilf, Larry H.,DeNittis, Albert,Sherwin, Nancy,Cho, Kwan H American Society for Clinical Oncology 2013 Journal of clinical oncology Vol.31 No.30

<P><B>Purpose</B></P><P>In this prospective National Cancer Institute–funded American College of Radiology Imaging Network/Radiation Therapy Oncology Group cooperative group trial, we hypothesized that standardized uptake value (SUV) on post-treatment [<SUP>18</SUP>F]fluorodeoxyglucose positron emission tomography (FDG-PET) correlates with survival in stage III non–small-cell lung cancer (NSCLC).</P><P><B>Patients and Methods</B></P><P>Patients received conventional concurrent platinum-based chemoradiotherapy without surgery; postradiotherapy consolidation chemotherapy was allowed. Post-treatment FDG-PET was performed at approximately 14 weeks after radiotherapy. SUVs were analyzed both as peak SUV (SUV<SUB>peak</SUB>) and maximum SUV (SUV<SUB>max</SUB>; both institutional and central review readings), with institutional SUV<SUB>peak</SUB> as the primary end point. Relationships between the continuous and categorical (cutoff) SUVs and survival were analyzed using Cox proportional hazards multivariate models.</P><P><B>Results</B></P><P>Of 250 enrolled patients (226 were evaluable for pretreatment SUV), 173 patients were evaluable for post-treatment SUV analyses. The 2-year survival rate for the entire population was 42.5%. Pretreatment SUV<SUB>peak</SUB> and SUV<SUB>max</SUB> (mean, 10.3 and 13.1, respectively) were not associated with survival. Mean post-treatment SUV<SUB>peak</SUB> and SUV<SUB>max</SUB> were 3.2 and 4.0, respectively. Post-treatment SUV<SUB>peak</SUB> was associated with survival in a continuous variable model (hazard ratio, 1.087; 95% CI, 1.014 to 1.166; <I>P</I> = .020). When analyzed as a prespecified binary value (≤ <I>v</I> > 3.5), there was no association with survival. However, in exploratory analyses, significant results for survival were found using an SUV<SUB>peak</SUB> cutoff of 5.0 (<I>P</I> = .041) or 7.0 (<I>P</I> < .001). All results were similar when SUV<SUB>max</SUB> was used in univariate and multivariate models in place of SUV<SUB>peak</SUB>.</P><P><B>Conclusion</B></P><P>Higher post-treatment tumor SUV (SUV<SUB>peak</SUB> or SUV<SUB>max</SUB>) is associated with worse survival in stage III NSCLC, although a clear cutoff value for routine clinical use as a prognostic factor is uncertain at this time.</P>