A 3D printable alloy designed for extreme environments.

Multiprincipal-element alloys are an enabling class of materials owing to their impressive mechanical and oxidation-resistant properties, especially in extreme environments1,2. Here we develop a new oxide-dispersion-strengthened NiCoCr-based alloy using a model-driven alloy design approach and laser-based additive manufacturing. This oxide-dispersion-strengthened alloy, called GRX-810, uses laser powder bed fusion to disperse nanoscale Y2O3 particles throughout the microstructure without the use of resource-intensive processing steps such as mechanical or in situ alloying3,4. We show the successful incorporation and dispersion of nanoscale oxides throughout the GRX-810 build volume via high-resolution characterization of its microstructure. The mechanical results of GRX-810 show a twofold improvement in strength, over 1,000-fold better creep performance and twofold improvement in oxidation resistance compared with the traditional polycrystalline wrought Ni-based alloys used extensively in additive manufacturing at 1,093 °C5,6. The success of this alloy highlights how model-driven alloy designs can provide superior compositions using far fewer resources compared with the 'trial-and-error' methods of the past. These results showcase how future alloy development that leverages dispersion strengthening combined with additive manufacturing processing can accelerate the discovery of revolutionary materials.

Enhanced simulated early 21st century Arctic sea ice loss due to CMIP6 biomass burning emissions.

The mechanisms underlying decadal variability in Arctic sea ice remain actively debated. Here, we show that variability in boreal biomass burning (BB) emissions strongly influences simulated Arctic sea ice on multidecadal time scales. In particular, we find that a strong acceleration in sea ice decline in the early 21st century in the Community Earth System Model version 2 (CESM2) is related to increased variability in prescribed BB emissions in the sixth phase of the Coupled Model Intercomparison Project (CMIP6) through summertime aerosol-cloud interactions. Furthermore, we find that more than half of the reported improvement in sea ice sensitivity to CO2 emissions and global warming from CMIP5 to CMIP6 can be attributed to the increased BB variability, at least in the CESM. These results highlight a new kind of uncertainty that needs to be considered when incorporating new observational data into model forcing while also raising questions about the role of BB emissions on the observed Arctic sea ice loss.

High-precision orientation mapping from spherical harmonic transform indexing of electron backscatter diffraction patterns.

The angular precision of crystal orientation determination by cross-correlating dynamically simulated electron diffraction patterns with experimental patterns via spherical harmonic analysis is investigated. The best precision found in this study is 0.016°, which approaches the level reported in the literature for other high-precision electron backscatter diffraction implementations. At this angular precision, the noise floor for geometrically necessary dislocation density calculations is found to be approximately 5×1013 m-2 at a 200 nm step size. Conventional Hough-transform indexing of the same raw patterns gave an angular precision of 0.156° and a dislocation noise floor of 6×1014 m-2, an order of magnitude larger for both parameters, albeit better than is typical for Hough indexing due to the high-quality patterns used. Experimental trade-off curves of precision versus exposure time, pattern resolution (i.e. camera binning), and analysis bandwidth are also presented, allowing for optimization of data collection and analysis rates once the desired level of precision has been determined.

On Recent Large Antarctic Ozone Holes and Ozone Recovery Metrics.

The 2015 and 2020 ozone holes set record sizes in October-December. We show that these years, as well as other recent large ozone holes, still adhere to a fundamental recovery metric: the later onset of early spring ozone depletion as chlorine and bromine diminishes. This behavior is also captured in the Whole Atmosphere Chemistry Climate Model. We quantify observed recovery trends of the onset of the ozone hole and in the size of the September ozone hole, with good model agreement. A substantial reduction in ozone hole depth during September over the past decade is also seen. Our results indicate that, due to dynamical phenomena, it is likely that large ozone holes will continue to occur intermittently in October-December, but ozone recovery will still be detectable through the later onset, smaller, and less deep September ozone holes: metrics that are governed more by chemical processes.

Persisting volcanic ash particles impact stratospheric SO2 lifetime and aerosol optical properties.

Volcanic ash is often neglected in climate simulations because ash particles are assumed to have a short atmospheric lifetime, and to not participate in sulfur chemistry. After the Mt. Kelut eruption in 2014, stratospheric ash-rich aerosols were observed for months. Here we show that the persistence of super-micron ash is consistent with a density near 0.5 g cm-3, close to pumice. Ash-rich particles dominate the volcanic cloud optical properties for the first 60 days. We also find that the initial SO2 lifetime is determined by SO2 uptake on ash, rather than by reaction with OH as commonly assumed. About 43% more volcanic sulfur is removed from the stratosphere in 2 months with the SO2 heterogeneous chemistry on ash particles than without. This research suggests the need for re-evaluation of factors controlling SO2 lifetime in climate model simulations, and of the impact of volcanic ash on stratospheric chemistry and radiation.

Achieving superelasticity in additively manufactured NiTi in compression without post-process heat treatment.

Shape memory alloys (SMAs), such as Nitinol (i.e., NiTi), are of great importance in biomedical and engineering applications due to their unique superelasticity and shape memory properties. In recent years, additive manufacturing (AM) processes have been used to produce complex NiTi components, which provide the ability to tailor microstructure and thus the critical properties of the alloys, such as the superelastic behavior and transformation temperatures (TTs), by selection of processing parameters. In biomedical applications, superelasticity in implants play a critical role since it gives the implants bone-like behavior. In this study, a methodology of improving superelasticity in Ni-rich NiTi components without the need for any kind of post-process heat treatments will be revealed. It will be shown that superelasticity with 5.62% strain recovery and 98% recovery ratio can be observed in Ni-rich NiTi after the sample is processed with 250 W laser power, 1250 mm/s scanning speed, and 80 µm hatch spacing without, any post-process heat treatments. This superelasticity in as-fabricated Ni-rich SLM NiTi was not previously possible in the absence of post-process heat treatments. The findings of this study promise the fast, reliable and inexpensive fabrication of complex shaped superelastic NiTi components for many envisioned applications such as patient-specific biomedical implants.

Embolization of hemorrhagic renal angiomyolipoma complicated by arteriovenous shunting: A case report.

Arteriovenous shunting associated with angiomyolipoma is an unusual entity, which carries important implications to embolization approach. We present a distinctive case involving a 41-year-old woman who presented with retroperitoneal hemorrhage relating to renal angiomyolipoma. During angiography for urgent embolization, a complex vascular supply with arteriovenous shunting was encountered. Superselective embolization using alcohol or small particles is the standard approach to definitive treatment of symptomatic angiomyolipoma; however; their use is precluded in the setting of arteriovenous shunt hemodynamics. In this case, a 2-step approach was employed by which the initial hemorrhage was treated with proximal embolization using large gelatin foam and metallic coils. This resulted in decreased flow through the arteriovenous shunt, allowing the use high viscosity ethylene vinyl alcohol copolymer dissolved in dimethyl sulfoxide for definitive treatment.

Effect of mixed partial occupation of metal sites on the phase stability of γ-Cr23-xFe x C6 (x = 0-3) carbides.

The effect of mixed partial occupation of metal sites on the phase stability of the γ-Cr23-xFe x C6 (x = 0-3) carbides is explored as function of composition and temperature. Ab initio calculations combined with statistical thermodynamics approaches reveal that the site occupation of the carbides may be incorrectly predicted when only the commonly used approach of full sublattice occupation is considered. We found that the γ-M23C6 structure can be understood as a familiar sodium chloride structure with positively charged rhombic dodecahedron (M(4a) M12(48h)) and negatively charged cubo-octahedron (M8(32f) C6(24e)) super-ion clusters, together with interstitial metal atoms at the 8c sites. The stability of the partially occupied phase can be easily rationalized on the basis of a super-ion analysis of the carbide phase. This new understanding of γ-M23C6 carbides may facilitate further development of high-chromium heat-resistant steels.

Magnetically-driven phase transformation strengthening in high entropy alloys.

CrCoNi alloy exhibits a remarkable combination of strength and plastic deformation, even superior to the CrMnFeCoNi high-entropy alloy. We connect the magnetic and mechanical properties of CrCoNi, via a magnetically tunable phase transformation. While both alloys crystallize as single-phase face-centered-cubic (fcc) solid solutions, we find a distinctly lower-energy phase in CrCoNi alloy with a hexagonal close-packed (hcp) structure. Comparing the magnetic configurations of CrCoNi with those of other equiatomic ternary derivatives of CrMnFeCoNi confirms that magnetically frustrated Mn eliminates the fcc-hcp energy difference. This highlights the unique combination of chemistry and magnetic properties in CrCoNi, leading to a fcc-hcp phase transformation that occurs only in this alloy, and is triggered by dislocation slip and interaction with internal boundaries. This phase transformation sets CrCoNi apart from the parent quinary, and its other equiatomic ternary derivatives, and provides a new way for increasing strength without compromising plastic deformation.

Effects of a Flexibility/Support Intervention on Work Performance: Evidence From the Work, Family, and Health Network.

PURPOSE: To estimate the effects of a workplace initiative to reduce work-family conflict on employee performance. DESIGN: A group-randomized multisite controlled experimental study with longitudinal follow-up. SETTING: An information technology firm. PARTICIPANTS: Employees randomized to the intervention (n = 348) and control condition (n = 345). INTERVENTION: An intervention, "Start. Transform. Achieve. Results." to enhance employees' control over their work time, to increase supervisors' support for this change, and to increase employees' and supervisors' focus on results. METHODS: We estimated the effect of the intervention on 9 self-reported employee performance measures using a difference-in-differences approach with generalized linear mixed models. Performance measures included actual and expected hours worked, absenteeism, and presenteeism. RESULTS: This study found little evidence that an intervention targeting work-family conflict affected employee performance. The only significant effect of the intervention was an approximately 1-hour reduction in expected work hours. After Bonferroni correction, the intervention effect is marginally insignificant at 6 months and marginally significant at 12 and 18 months. CONCLUSION: The intervention reduced expected working time by 1 hour per week; effects on most other employee self-reported performance measures were statistically insignificant. When coupled with the other positive wellness and firm outcomes, this intervention may be useful for improving employee perceptions of increased access to personal time or personal wellness without sacrificing performance. The null effects on performance provide countervailing evidence to recent negative press on work-family and flex work initiatives.

Project to Improve the Transcription of Clinical Order Information into a Radiology Information System.

CONTEXT: Inaccurate and incomplete imaging order information presented to interpreting radiologists is a persistent problem in many radiology settings. Computerized Physician Order Entry processes in clinic-based settings are often inconsistent, and radiology transcription clerks continue to play a critical role in transmitting accurate content and information from referring physician orders to the radiology information system. (RIS) The purpose of this quality improvement project was to a) identify common transcription areas of deficient RIS imaging order information and b) test outcomes from an intervention to improve the content and concordance of transcribed patient information entered into the RIS. METHODS: A random convenience sample of 500 outpatient radiographic orders were categorized according to degree and quality of concordance between the transcribed patient information documented in the RIS and the corresponding original imaging order information. During Phase I, the authors used a root-cause analysis to determine the possible etiologies for discordance between the information in original imaging orders and the information transcribed into the RIS. The intervention that was delivered included a short education session with radiology transcription clerks with placement reminder posters at transcription workstations. During Phase 2, a second random sample was obtained following the intervention, with data collection and analyses replicating the process from Phase I. A set of inferential comparisons were conducted using chi-square tests to examine for statistical significance. RESULTS: There was an overall 44% decrease in transcription discordance (p < 0.001), and the number of cases with perfectly concordant RIS order indication documentations increased by 21% (p < 0.001). A total of 34% of transcriptions from Phase I were partially discordant due to an inadequate imaging study indication, compared to 15% during Phase II (p < 0.001). There was also a 22% increase in the number of completely concordant transcriptions free of grammatical errors (p < 0.001). CONCLUSIONS: A short education session with radiology transcription clerks along with placement of reminder posters may significantly improve both the concordance and quality of transcribed imaging order information presented to interpreting radiologists using the RIS.

Cost and Return on Investment of a Work-Family Intervention in the Extended Care Industry: Evidence From the Work, Family, and Health Network.

OBJECTIVE: To estimate the cost and return on investment (ROI) of an intervention targeting work-family conflict (WFC) in the extended care industry. METHODS: Costs to deliver the intervention during a group-randomized controlled trial were estimated, and data on organizational costs-presenteeism, health care costs, voluntary termination, and sick time-were collected from interviews and administrative data. Generalized linear models were used to estimate the intervention's impact on organizational costs. Combined, these results produced ROI estimates. A cluster-robust confidence interval (CI) was estimated around the ROI estimate. RESULTS: The per-participant cost of the intervention was $767. The ROI was -1.54 (95% CI: -4.31 to 2.18). The intervention was associated with a $668 reduction in health care costs (P < 0.05). CONCLUSIONS: This paper builds upon and expands prior ROI estimation methods to a new setting.

Sustaining SBIRT in the wild: simulating revenues and costs for Screening, Brief Intervention and Referral to Treatment programs.

AIMS: To examine the conditions under which Screening, Brief Intervention and Referral to Treatment (SBIRT) programs can be sustained by health insurance payments. DESIGN: A mathematical model was used to estimate the number of patients needed for revenues to exceed costs. SETTING: Three medical settings in the United States were examined: in-patient, out-patient and emergency department. Components of SBIRT were delivered by combinations of health-care practitioners (generalists) and behavioral health specialists. PARTICIPANTS: Practitioners in seven SBIRT programs who received grants from the US Substance Abuse and Mental Health Services Administration (SAMHSA). MEASUREMENTS: Program costs and revenues were measured using data from grantees. Patient flows were measured from administrative data and adjusted with prevalence and screening estimates from the literature. FINDINGS: SBIRT can be sustained through health insurance reimbursement in out-patient and emergency department settings in most staffing mixes. To sustain SBIRT in in-patient programs, a patient flow larger than the national average may be needed; if that flow is achieved, the range of screens required to maintain a surplus is narrow. Sensitivity analyses suggest that the results are very sensitive to changes in the proportion of insured patients. CONCLUSIONS: Screening, Brief Intervention and Referral to Treatment programs in the United States can be sustained by health insurance payments under a variety of staffing models. Screening, Brief Intervention and Referral to Treatment programs can be sustained only in an in-patient setting with above-average patient flow (more than 2500 screens). Screening, Brief Intervention and Referral to Treatment programs in out-patient and emergency department settings can be sustained with below-average patient flows (fewer than 125 000 out-patient visits and fewer than 27 000 emergency department visits).

Solute segregation and deviation from bulk thermodynamics at nanoscale crystalline defects.

It has long been known that solute segregation at crystalline defects can have profound effects on material properties. Nevertheless, quantifying the extent of solute segregation at nanoscale defects has proven challenging due to experimental limitations. A combined experimental and first-principles approach has been used to study solute segregation at extended intermetallic phases ranging from 4 to 35 atomic layers in thickness. Chemical mapping by both atom probe tomography and high-resolution scanning transmission electron microscopy demonstrates a markedly different composition for the 4-atomic-layer-thick phase, where segregation has occurred, compared to the approximately 35-atomic-layer-thick bulk phase of the same crystal structure. First-principles predictions of bulk free energies in conjunction with direct atomistic simulations of the intermetallic structure and chemistry demonstrate the breakdown of bulk thermodynamics at nanometer dimensions and highlight the importance of symmetry breaking due to the proximity of interfaces in determining equilibrium properties.

Surface dimming by the 2013 Rim Fire simulated by a sectional aerosol model.

The Rim Fire of 2013, the third largest area burned by fire recorded in California history, is simulated by a climate model coupled with a size-resolved aerosol model. Modeled aerosol mass, number, and particle size distribution are within variability of data obtained from multiple-airborne in situ measurements. Simulations suggest that Rim Fire smoke may block 4-6% of sunlight energy reaching the surface, with a dimming efficiency around 120-150 W m-2 per unit aerosol optical depth in the midvisible at 13:00-15:00 local time. Underestimation of simulated smoke single scattering albedo at midvisible by 0.04 suggests that the model overestimates either the particle size or the absorption due to black carbon. This study shows that exceptional events like the 2013 Rim Fire can be simulated by a climate model with 1° resolution with overall good skill, although that resolution is still not sufficient to resolve the smoke peak near the source region.

Emergence of healing in the Antarctic ozone layer.

Industrial chlorofluorocarbons that cause ozone depletion have been phased out under the Montreal Protocol. A chemically driven increase in polar ozone (or "healing") is expected in response to this historic agreement. Observations and model calculations together indicate that healing of the Antarctic ozone layer has now begun to occur during the month of September. Fingerprints of September healing since 2000 include (i) increases in ozone column amounts, (ii) changes in the vertical profile of ozone concentration, and (iii) decreases in the areal extent of the ozone hole. Along with chemistry, dynamical and temperature changes have contributed to the healing but could represent feedbacks to chemistry. Volcanic eruptions have episodically interfered with healing, particularly during 2015, when a record October ozone hole occurred after the Calbuco eruption.

Return on Investment of a Work-Family Intervention: Evidence From the Work, Family, and Health Network.

OBJECTIVE: To estimate the return on investment (ROI) of a workplace initiative to reduce work-family conflict in a group-randomized 18-month field experiment in an information technology firm in the United States. METHODS: Intervention resources were micro-costed; benefits included medical costs, productivity (presenteeism), and turnover. Regression models were used to estimate the ROI, and cluster-robust bootstrap was used to calculate its confidence interval. RESULTS: For each participant, model-adjusted costs of the intervention were $690 and company savings were $1850 (2011 prices). The ROI was 1.68 (95% confidence interval, -8.85 to 9.47) and was robust in sensitivity analyses. CONCLUSION: The positive ROI indicates that employers' investment in an intervention to reduce work-family conflict can enhance their business. Although this was the first study to present a confidence interval for the ROI, results are comparable with the literature.

Evaluations of tropospheric aerosol properties simulated by the community earth system model with a sectional aerosol microphysics scheme.

A sectional aerosol model (CARMA) has been developed and coupled with the Community Earth System Model (CESM1). Aerosol microphysics, radiative properties, and interactions with clouds are simulated in the size-resolving model. The model described here uses 20 particle size bins for each aerosol component including freshly nucleated sulfate particles, as well as mixed particles containing sulfate, primary organics, black carbon, dust, and sea salt. The model also includes five types of bulk secondary organic aerosols with four volatility bins. The overall cost of CESM1-CARMA is approximately ∼2.6 times as much computer time as the standard three-mode aerosol model in CESM1 (CESM1-MAM3) and twice as much computer time as the seven-mode aerosol model in CESM1 (CESM1-MAM7) using similar gas phase chemistry codes. Aerosol spatial-temporal distributions are simulated and compared with a large set of observations from satellites, ground-based measurements, and airborne field campaigns. Simulated annual average aerosol optical depths are lower than MODIS/MISR satellite observations and AERONET observations by ∼32%. This difference is within the uncertainty of the satellite observations. CESM1/CARMA reproduces sulfate aerosol mass within 8%, organic aerosol mass within 20%, and black carbon aerosol mass within 50% compared with a multiyear average of the IMPROVE/EPA data over United States, but differences vary considerably at individual locations. Other data sets show similar levels of comparison with model simulations. The model suggests that in addition to sulfate, organic aerosols also significantly contribute to aerosol mass in the tropical UTLS, which is consistent with limited data.

Costs of alcohol screening and brief intervention in medical settings: a review of the literature.

OBJECTIVE: This article summarizes the literature on the implementation costs of alcohol screening and brief intervention (SBI) in medical settings. METHOD: Electronic databases were searched using SBI- and cost-related terms. Methodological approaches and cost estimates were abstracted from each study and categorized based on the cost methodology. Costs were updated to 2009 U.S. dollars. To determine a summary cost measure, we excluded outliers and computed the median of the remaining cost estimates. RESULTS: Seventeen studies with cost estimates were identified for further study. Costs ranged from $0.51 to $601.50 per screen and from $3.41 to $243.01 per brief intervention (BI). Cost estimates were lower when an activity-based cost methodology was used, in primary care settings, and when the provider was not a doctor. The median summary cost of a screen is approximately $4, and the median summary cost of a BI is approximately $48. CONCLUSIONS: Screening cost estimates had more variation than BI cost estimates. Provider type and service delivery time drive the cost variation. Interpretation of cost differences was limited by insufficient reporting of the cost methodology. Cost estimates presented here are similar in size to the Healthcare Common Procedure Coding System and Current Procedural Terminology reimbursement amounts, suggesting that insurance-based service reimbursement may be sufficient to sustain alcohol SBI in practice.

Cost-effectiveness analysis of motivational interviewing with feedback to reduce drinking among a sample of college students.

OBJECTIVE: This study evaluated the costs and cost-effectiveness of combining motivational interviewing with feedback to address heavy drinking among university freshmen. METHOD: Microcosting methods were used in a prospective cost and cost-effectiveness study of a randomized trial of assessment only (AO), motivational interviewing (MI), feedback only (FB), and motivational interviewing with feedback (MIFB) at a large public university in the southeastern United States. Students were recruited and screened into the study during freshman classes based on recent heavy drinking. A total of 727 students (60% female) were randomized, and 656 had sufficient data at 3-months' follow-up to be included in the cost-effectiveness analysis. Effectiveness outcomes were changes in average drinks per drinking occasion and number of heavy drinking occasions. RESULTS: Mean intervention costs per student were $16.51 for MI, $17.33 for FB, and $36.03 for MIFB. Cost-effectiveness analysis showed two cost-effective interventions for both outcomes: AO ($0 per student) and MIFB ($36 per student). CONCLUSIONS: This is the first prospective cost-effectiveness study to our knowledge to examine MI for heavy drinking among students in a university setting. Despite being the most expensive intervention, MIFB was the most effective intervention and may be a cost-effective intervention, depending on a university's willingness to pay for changes in the considered outcomes.