Analysis of a Novel SPS Configuration Enabled by Lunar ISRU

Architectures for space-based solar power using in situ resource utilization (ISRU) of space materials can greatly reduce earth launch mass and can enable geometric capacity growth. These two factors allow the potential for low cost power generation after development of an in-space infrastructure. A collection of extraction and processing methods designed for lunar operation provides for large volumes of low cost solar panels. With abundant panels a novel configuration for solar power satellites (SPS) is possible which avoids many of the challenges of existing designs. The so-called "tin can" SPS has no moving parts. It includes integral thermal radiators. Station-keeping requirements are minimal. Structural integrity is designed-in so that balance of plant mass is minimal. In this work the architecture and infrastructure supporting the tin can SPS is developed to support rapid construction and deployment. Performance estimates for the SPS are provided regarding heat and energy balance, and specific mass requirements

Safety-related operator actions: methodology for developing criteria

This report presents a methodology for developing criteria for design evaluation of safety-related actions by nuclear power plant reactor operators, and identifies a supporting data base. It is the eleventh and final NUREG/CR Report on the Safety-Related Operator Actions Program, conducted by Oak Ridge National Laboratory for the US Nuclear Regulatory Commission. The operator performance data were developed from training simulator experiments involving operator responses to simulated scenarios of plant disturbances; from field data on events with similar scenarios; and from task analytic data. A conceptual model to integrate the data was developed and a computer simulation of the model was run, using the SAINT modeling language. Proposed is a quantitative predictive model of operator performance, the Operator Personnel Performance Simulation (OPPS) Model, driven by task requirements, information presentation, and system dynamics. The model output, a probability distribution of predicted time to correctly complete safety-related operator actions, provides data for objective evaluation of quantitative design criteria

Effect of Depth and Duration of Cooling on Death or Disability at Age 18 Months Among Neonates With Hypoxic-Ischemic Encephalopathy: A Randomized Clinical Trial

Importance Hypothermia for 72 hours at 33.5°C for neonatal hypoxic-ischemic encephalopathy reduces death or disability, but rates continue to be high. Objective To determine if cooling for 120 hours or to a temperature of 32.0°C reduces death or disability at age 18 months in infants with hypoxic-ischemic encephalopathy. Design, Setting, and Participants Randomized 2 × 2 factorial clinical trial in neonates (≥36 weeks’ gestation) with hypoxic-ischemic encephalopathy at 18 US centers in the Eunice Kennedy Shriver National Institute of Child Health and Human Development Neonatal Research Network between October 2010 and January 2016. Interventions A total of 364 neonates were randomly assigned to 4 hypothermia groups: 33.5°C for 72 hours (n = 95), 32.0°C for 72 hours (n = 90), 33.5°C for 120 hours (n = 96), or 32.0°C for 120 hours (n = 83). Main Outcomes and Measures The primary outcome was death or moderate or severe disability at 18 to 22 months of age adjusted for center and level of encephalopathy. Severe disability included any of Bayley Scales of Infant Development III cognitive score less than 70, Gross Motor Function Classification System (GMFCS) level of 3 to 5, or blindness or hearing loss despite amplification. Moderate disability was defined as a cognitive score of 70 to 84 and either GMFCS level 2, active seizures, or hearing with amplification. Results The trial was stopped for safety and futility in November 2013 after 364 of the planned 726 infants were enrolled. Among 347 infants (95%) with primary outcome data (mean age at follow-up, 20.7 [SD, 3.5] months; 42% female), death or disability occurred in 56 of 176 (31.8%) cooled for 72 hours and 54 of 171 (31.6%) cooled for 120 hours (adjusted risk ratio, 0.92 [95% CI, 0.68-1.25]; adjusted absolute risk difference, −1.0% [95% CI, −10.2% to 8.1%]) and in 59 of 185 (31.9%) cooled to 33.5°C and 51 of 162 (31.5%) cooled to 32.0°C (adjusted risk ratio, 0.92 [95% CI, 0.68-1.26]; adjusted absolute risk difference, −3.1% [95% CI, −12.3% to 6.1%]). A significant interaction between longer and deeper cooling was observed (P = .048), with primary outcome rates of 29.3% at 33.5°C for 72 hours, 34.5% at 32.0°C for 72 hours, 34.4% at 33.5°C for 120 hours, and 28.2% at 32.0°C for 120 hours. Conclusions and Relevance Among term neonates with moderate or severe hypoxic-ischemic encephalopathy, cooling for longer than 72 hours, cooling to lower than 33.5°C, or both did not reduce death or moderate or severe disability at 18 months of age. However, the trial may be underpowered, and an interaction was found between longer and deeper cooling. These results support the current regimen of cooling for 72 hours at 33.5°C

Weaning of Moderately Preterm Infants from the Incubator to the Crib: A Randomized Clinical Trial

OBJECTIVE: To assess whether length of hospital stay is decreased among moderately preterm infants weaned from incubator to crib at a lower vs higher weight. STUDY DESIGN: This trial was conducted in the Eunice Kennedy Shriver National Institute of Child Health and Human Development Neonatal Research Network. Infants with gestational ages 29-33 weeks, birthweight <1600 g, and in an incubator were randomly assigned to a weaning weight of 1600 or 1800 g. Within 60 to 100 g of weaning weight, the incubator temperature was decreased by 1.0°C to 1.5°C every 24 hours until 28.0°C. The infants were weaned to the crib following stable temperature at 36.5°C to 37.4°C for 8 to 12 hours. Clothing and bedcoverings were standardized. The primary outcome was length of hospital stay from birth to discharge; secondary outcomes included length of stay and growth velocity from weaning to discharge. Adverse events were monitored. RESULTS: Of 1565 infants screened, 885 were eligible, and 366 enrolled-187 to the 1600-g and 179 to the 1800-g group. Maternal and neonatal characteristics did not differ among weight groups. Length of hospital stay was a median of 43 days in the lower and 41 days in the higher weight group (P = .12). Growth velocity from completion of weaning to discharge was higher in the lower weight group, 13.7 g/kg/day vs 12.8 g/kg/day (P = .005). Groups did not differ in adverse events. CONCLUSIONS: Among moderately preterm neonates, weaning from incubator to crib at a lower weight did not decrease length of stay, but was safe and was accompanied by higher weight gain after weaning

Mechanical origins of lithium-metal intrusions into garnet solid electrolytes revealed by failure statistics

Solid-state electrolytes are an attractive option to increase the chemical stability and energy density of rechargeable lithium-metal batteries. However, they are susceptible to lithium-metal short-circuiting during charging, especially under high current densities. In this work, using a force-controlled electrical microprobe inside a focused-ion beam scanning electron microscope, we performed 48 experiments of electroplating lithium metal onto Li6.6La3 Ta0.4Zr1.6O12 (LLZO) and observed the initiation of lithium penetration (termed intrusions) into the solid electrolyte, with and without externally applied stress. Employing a statistical approach, we find that the cumulative probability of intrusion as a function of lithium metal diameter follows a two-parameter Weibull distribution, implying defect-governed fracture behavior for the intrusion initiation. Upon applying a contact force of 5 mN with a 5-10 µm microprobe, the characteristic failure diameter of lithium metal decreases by a factor of 2.6 due to the generation of nanoscale cracks as suggested by nanoindentation and finite element simulations. Furthermore, we introduce in-plane compressive strain to LLZO through a cantilever bending experiment and demonstrate that strain as small as 0.067% strongly influences the direction of intrusion propagation immediately following initiation. Overall, our results suggest that both mechanically-generated and pre-existing defects as well as mechanical strain dominate the intrusion behavior in LLZO, a phenomenon that could extend to other solid electrolytes

Outcome of Preterm Infants with Transient Cystic Periventricular Leukomalacia on Serial Cranial Imaging Up to Term Equivalent Age

To determine the outcome of preterm infants whose cystic periventricular leukomalacia "disappeared" on serial screening cranial imaging studies. Infants ≤26 weeks of gestation born between 2002 and 2012 who had cranial imaging studies at least twice, the most abnormal study at <28 days of age and another closest to 36 weeks, were reviewed. The outcome of late death (after 36 weeks postmenstrual age) or neurodevelopmental impairment (NDI) in surviving infants at 18-26 months corrected age was compared between the infants with no cystic periventricular leukomalacia on both studies and cystic periventricular leukomalacia that disappeared (cystic periventricular leukomalacia at <28 days but not at 36 weeks), persisted (cystic periventricular leukomalacia on both studies), or appeared late (cystic periventricular leukomalacia only at 36 weeks). Predictors of NDI were evaluated by logistic regression. Of 7063 eligible infants, 433 (6.1%) had cystic periventricular leukomalacia. Among the 433 infants with cystic periventricular leukomalacia, cystic periventricular leukomalacia disappeared in 76 (18%), persisted in 87 (20%), and 270 (62%) had late cystic periventricular leukomalacia. Loss to follow-up ranged between 3% and 13%. Death or NDI was more common in infants with disappeared cystic periventricular leukomalacia compared with those with no cystic periventricular leukomalacia (38 of 72 [53%] vs 1776 of 6376 [28%]; OR [95% CI] 2.8 [1.8-4.6]). Disappeared, persistent, and late cystic periventricular leukomalacia were all also independently associated with NDI (OR 1.17, 1.21, and 1.16, respectively). Infants with "disappeared" cystic periventricular leukomalacia are at increased risk of adverse outcome similar to infants with persistent or late cystic periventricular leukomalacia

Weaning of Moderately Preterm Infants from the Incubator to the Crib: A Randomized Clinical Trial.

ObjectiveTo assess whether length of hospital stay is decreased among moderately preterm infants weaned from incubator to crib at a lower vs higher weight.Study designThis trial was conducted in the Eunice Kennedy Shriver National Institute of Child Health and Human Development Neonatal Research Network. Infants with gestational ages 29-33 weeks, birthweight &lt;1600 g, and in an incubator were randomly assigned to a weaning weight of 1600 or 1800 g. Within 60 to 100 g of weaning weight, the incubator temperature was decreased by 1.0°C to 1.5°C every 24 hours until 28.0°C. The infants were weaned to the crib following stable temperature at 36.5°C to 37.4°C for 8 to 12 hours. Clothing and bedcoverings were standardized. The primary outcome was length of hospital stay from birth to discharge; secondary outcomes included length of stay and growth velocity from weaning to discharge. Adverse events were monitored.ResultsOf 1565 infants screened, 885 were eligible, and 366 enrolled-187 to the 1600-g and 179 to the 1800-g group. Maternal and neonatal characteristics did not differ among weight groups. Length of hospital stay was a median of 43 days in the lower and 41 days in the higher weight group (P = .12). Growth velocity from completion of weaning to discharge was higher in the lower weight group, 13.7 g/kg/day vs 12.8 g/kg/day (P = .005). Groups did not differ in adverse events.ConclusionsAmong moderately preterm neonates, weaning from incubator to crib at a lower weight did not decrease length of stay, but was safe and was accompanied by higher weight gain after weaning.Trial registrationClinicalTrials.gov: NCT02160002

Delivery Room Resuscitation and Short-Term Outcomes in Moderately Preterm Infants

ObjectivesTo describe the frequency and extent of delivery room resuscitation and evaluate the association of delivery room resuscitation with neonatal outcomes in moderately preterm (MPT) infants.Study designThis was an observational cohort study of MPT infants delivered at 290/7 to 336/7 weeks' gestational age (GA) enrolled in the Neonatal Research Network MPT registry. Infants were categorized into 5 groups based on the highest level of delivery room intervention: routine care, oxygen and/or continuous positive airway pressure, bag and mask ventilation, endotracheal intubation, and cardiopulmonary resuscitation including chest compressions and/or epinephrine use. The association of antepartum and intrapartum risk factors and discharge outcomes with the intensity of resuscitation was evaluated.ResultsOf 7014 included infants, 1684 (24.0%) received routine care and no additional resuscitation, 2279 (32.5%) received oxygen or continuous positive airway pressure, 1831 (26.1%) received bag and mask ventilation, 1034 (14.7%) underwent endotracheal intubation, and 186 (2.7%) received cardiopulmonary resuscitation. Among the antepartum and intrapartum factors, increasing GA, any exposure to antenatal steroids and prolonged rupture of membranes decreased the likelihood of receipt of all levels of resuscitation. Infants who were small for GA (SGA) had increased risk of delivery room resuscitation. Among the neonatal outcomes, respiratory support at 28 days, days to full oral feeds and length of stay were significantly associated with the intensity of delivery room resuscitation. Higher intensity of resuscitation was associated with increased risk of mortality.ConclusionsThe majority of MPT infants receive some level of delivery room resuscitation. Increased intensity of delivery room interventions was associated with prolonged respiratory and nutritional support, increased mortality, and a longer length of stay