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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 1,531 records · Page 85
All sourcesNASA NTRSDOE OSTI
DOE OSTI2017

Phase-Transformation Ductilization of Brittle High-Entropy Alloys via Metastability Engineering

High-entropy alloys (HEAs) in which interesting physical, chemical, and structural properties are being continuously revealed have recently attracted extensive attention. Body-centered cubic (bcc) HEAs, particularly those based on refractory elements are promising for high-temperature application but generally fail by early cracking with limited plasticity at room temperature, which limits their malleability and widespread uses. In this paper, the “metastability-engineering” strategy is exploited in brittle bcc HEAs via tailoring the stability of the constituent phases, and transformation-induced ductility and work-hardening capability are successfully achieved. Finally, this not only sheds new insights on the development of HEAs with excellent combination of strength and ductility, but also has great implications on overcoming the long-standing strength–ductility tradeoff of metallic materials in general.

36 MATERIALS SCIENCE↗
DOE OSTI2025

Control of Two Solid Electrolyte Interphases at the Negative Electrode of an Anode‐Free All Solid‐State Battery based on Argyrodite Electrolyte

Abstract Anode‐free all solid‐state batteries (AF‐ASSBs) employ “empty” current collector with three active interfaces that determine electrochemical stability; lithium metal – Solid electrolyte (SE) interphase (SEI‐1), lithium – current collector interface, and collector – SE interphase (SEI‐2). Argyrodite Li 6 PS 5 Cl (LPSCl) solid electrolyte (SE) displays SEI‐2 containing copper sulfides, formed even at open circuit. Bilayer of 140 nm magnesium/30 nm tungsten (Mg/W‐Cu) controls the three interfaces and allows for state‐of‐the‐art electrochemical performance in half‐cells and fullcells. AF‐ASSB with NMC811 cathode achieves 150 cycles with Coulombic efficiency (CE) above 99.8%. With high mass‐loading cathode (8.6 mAh cm −2 ), AF‐ASSB retains 86.5% capacity after 45 cycles at 0.2C. During electrodeposition of Li, gradient Li‐Mg solid solution is formed, which reverses upon electrodissolution. This promotes conformal wetting/dewetting by Li and stabilizes SEI‐1 by lowering thermodynamic driving force for SE reduction. Inert refractory W underlayer is required to prevent ongoing formation of SEI‐2 that also drives electrochemical degradation. Inert Mo and Nb layers likewise protect Cu from corroding, while Li‐alloying layers (Mg, Sn) are less effective due to ongoing volume changes and associated pulverization. Mechanistic explanation for observed Li segregation within alloying Li x Mg layer is provided through mesoscale modelling, considering opposing roles of diffusivity differences and interfacial stresses.

Wang, Yixian [Materials Science and Engineering Pr↗
DOE OSTI2016

Lithography-free large-area metamaterials for stable thermophotovoltaic energy conversion

A large-area metamaterial thermal emitter is fabricated using facile, lithography-free techniques. The device is composed of conductive oxides, refractory ceramics, and noble metals and shows stable, selective emission after exposure to 1173 K for 22 h in oxidizing and inert atmospheres. Lastly, the results indicate that the metamaterial can be used to achieve high-performance thermophotovoltaic devices for applications such as portable power generation.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗
DOE OSTI2025

Demonstration of Complete Recycling Processes of Reversible Epoxies Using Solar Energy Conversion

Reversible epoxies using the Diels–Alder chemistry enables recycling processes through depolymerizing the polymer at higher temperature and then repolymerizing upon cooling. Compared to conventional bulk heating, photothermal heating can save time and resource and, consequently, reduce costs to reach an elevated temperature for recycling processes of the reversible epoxies. In previous studies, self‐healing of cracks and reattachments of two broken pieces have been presented using a laser; however, recycling of a sample as a whole is not feasible by using such a point light source. Herein, complete recycling processes are demonstrated utilizing an area light source, i.e., sunlight. Reversible epoxies are incorporated with carbon black and refractory plasmonic titanium nitride nanoparticles (NPs). Under concentrated (10 times) sunlight, they can generate sufficient heat (≈140 °C) to completely liquefy, reprocess, and reshape the samples multiple times. Recycling processes are validated by evaluation of mechanical properties for each cycle. Using an integrated experimental and theoretical approach, photothermal performance is investigated in terms of the dispersion and loading of photothermal NPs in the matrix, as well as the sample thickness. In this study, an insight is provided into the design of polymer/photothermal nanomaterial composites which can be sustainably recycled using abundant solar energy.

14 SOLAR ENERGY↗
DOE OSTI2023

Treatment of cholinergic‐induced status epilepticus with polytherapy targeting GABA and glutamate receptors

Abstract Despite new antiseizure medications, the development of cholinergic‐induced refractory status epilepticus (RSE) continues to be a therapeutic challenge as pharmacoresistance to benzodiazepines and other antiseizure medications quickly develops. Studies conducted by Epilepsia . 2005;46:142 demonstrated that the initiation and maintenance of cholinergic‐induced RSE are associated with trafficking and inactivation of gamma‐aminobutyric acid A receptors (GABA A R) thought to contribute to the development of benzodiazepine pharmacoresistance. In addition, Dr. Wasterlain's laboratory reported that increased N‐methyl‐ d ‐aspartate receptors (NMDAR) and alpha‐amino‐3‐hydroxy‐5‐methyl‐4‐isoxazolepropionic acid receptors (AMPAR) contribute to enhanced glutamatergic excitation ( Neurobiol Dis . 2013;54:225; Epilepsia . 2013;54:78). Thus, Dr. Wasterlain postulated that targeting both maladaptive responses of reduced inhibition and increased excitation that is associated with cholinergic‐induced RSE should improve therapeutic outcome. We currently review studies in several animal models of cholinergic‐induced RSE that demonstrate that benzodiazepine monotherapy has reduced efficacy when treatment is delayed and that polytherapy with drugs that include a benzodiazepine (eg midazolam and diazepam) to counter loss of inhibition, concurrent with an NMDA antagonist (eg ketamine) to reduce excitation provide improved efficacy. Improved efficacy with polytherapy against cholinergic‐induced seizure is demonstrated by reduction in (1) seizure severity, (2) epileptogenesis, and (3) neurodegeneration compared with monotherapy. Animal models reviewed include pilocarpine‐induced seizure in rats, organophosphorus nerve agent (OPNA)‐induced seizure in rats, and OPNA‐induced seizure in two mouse models: (1) carboxylesterase knockout (Es1 −/− ) mice which, similarly to humans, lack plasma carboxylesterase and (2) human acetylcholinesterase knock‐in carboxylesterase knockout (KIKO) mice. We also review studies showing that supplementing midazolam and ketamine with a third antiseizure medication (valproate or phenobarbital) that targets a nonbenzodiazepine site rapidly terminates RSE and provides further protection against cholinergic‐induced SE. Finally, we review studies on the benefits of simultaneous compared with sequential drug treatments and the clinical implications that lead us to predict improved efficacy of early combination drug therapies. The data generated from seminal rodent studies of efficacious treatment of cholinergic‐induced RSE conducted under Dr. Wasterlain's guidance suggest that future clinical trials should treat the inadequate inhibition and temper the excess excitation that characterize RSE and that early combination therapies may provide improved outcome over benzodiazepine monotherapy.

59 BASIC BIOLOGICAL SCIENCES↗
DOE OSTI2013

Plasma Panel Based Radiation Detectors

The plasma panel sensor (PPS) is a gaseous micropattern radiation detector under current development. It has many operational and fabrication principles common to plasma display panels (PDPs). It comprises a dense matrix of small, gas plasma discharge cells within a hermetically sealed panel. As in PDPs, it uses non-reactive, intrinsically radiation-hard materials such as glass substrates, refractory metal electrodes, and mostly inert gas mixtures. We are developing these devices primarily as thin, low-mass detectors with gas gaps from a few hundred microns to a few millimeters. The PPS is a high gain, inherently digital device with the potential for fast response times, fine position resolution (< 50 m RMS) and low cost. In this paper we report here on prototype PPS experimental results in detecting betas, protons and cosmic muons, and we extrapolate on the PPS potential for applications including detection of alphas, heavy-ions at low to medium energy, thermal neutrons and X-rays.

Friedman, Dr. Peter S.↗
DOE OSTI2024

Antimicrobial mechanisms of g‐C 3 N 4 @ ZnO against oomycetes Phytophthora capsici: from its metabolism, membrane structures and growth

Abstract BACKGROUND Phytophthora capsici , a refractory and model oomycete plant pathogen, especially threatens multiple vegetable crops. A limited number of chemical pesticides play a vital role in controlling oomycete plant diseases. However, this approach often leads to excessive use of chemical agent, exacerbates environmental issues and more and more drug‐resistant strains of oomycete. Therefore, it is imperative to devise innovative solutions that can effectively address the infection of oomycete while maintaining high levels of environmental sustainability and low toxicity. RESULTS In this study, g‐C 3 N 4 @ZnO heterostructure was synthesized and characterized. The g‐C 3 N 4 @ZnO showed higher toxicity on Phytophthora capsici than graphitic carbon nitride (g‐C 3 N 4 ) nanosheets and zinc oxide (ZnO) nanoparticles in vitro and in vivo . Except the hyphal growth of Phytophthora capsici , their germination rate of spores, sporangium formation and number of spores were all suppressed by g‐C 3 N 4 @ZnO heterostructure. Furthermore, we found that this g‐C 3 N 4 @ZnO heterostructure has higher photocatalytic activity under visible light, which potentially enhanced the reactive oxygen species (ROS) mediated stress on Phytophthora capsici . Ultrastructural morphology, global changes of gene expression and weighted gene co‐expression network analysis all supported that the anti‐oomycete activity of g‐C 3 N 4 @ZnO was manifested in the destruction of membrane system and inhibition of multiple metabolisms of Phytophthora capsici under visible irradiation, which also could be attributed to the ROS and zinc ion (Zn 2+ ) mediated stress. CONCLUSION This works offers a novel oomycete disease management strategy by using g‐C 3 N 4 @ZnO, which were attributed to the ROS stress, destruction of membrane system and inhibition of multiple metabolisms. © 2023 Society of Chemical Industry.

Cai, Lin↗
DOE OSTI2024

Comparison of the Effect of 2 at. % Additions of Nb and Ta on the 1100 °C Oxidation Behavior of Ni-6Al-(4,6,8) Cr Model Alloys

To continue improving alloy performance in harsh service environments, the development of alumina-forming nickel-based superalloys is essential. Current generations of these alloys heavily rely on the addition of refractory elements to enhance their mechanical properties at high temperatures; however, a systematic understanding of how such additions affect the overall oxidation behavior is still not well established, particularly from the standpoint of predicting the transition from internal to external alumina formation. The present work seeks to better understand the intrinsic effects that common minor additions of Ta and Nb have on the oxidation behavior of alumina-scale-forming γ-Ni model alloys. By combining a novel simulation approach with high-temperature oxidation experiments and advanced characterization techniques, the present study provides insightful details on the differing effects that 2 at. % addition of Ta and Nb have on the alumina scale formation of Ni-based alloys during 1100 °C oxidation.

Rodriguez, Rafael↗
DOE OSTI2019

CT imaging of inflatable penile prosthesis complications: a pictorial essay

Purpose: Inflatable penile prostheses (IPPs) are widely used in the United States, for patients with erectile dysfunction refractory to other treatments. Complications subsequent to IPP insertion include infection, hematoma, fluid leak, component (cylinder/pump/reservoir) complications, and retained previous IPP components. Radiologists are often called upon to identify and characterize these complications utilizing CT prior to intervention. Our paper aims to provide a guide to familiarize radiologists with normal IPP component imaging and review the CT findings of commonly encountered complications. Methods: In this study, we retrospectively reviewed CT reports with descriptions of IPPs from 108 patients. We collected CT images of normal IPP components as well as reevaluated the CT findings of 33 patients with an IPP complication and correlated with immediately subsequent operative report. Results: The CT appearance of appropriately positioned normal IPP components in asymptomatic patients and each complication were described and compared to previous literature. Conclusions: CT is a very useful modality to assess an IPP-related complication. It is inexpensive, fast, and immediately available in emergent situations, e.g., infection, hematoma, and component erosion. Additionally, CT is very sensitive and makes it easier to diagnose a system leak. It can identify most cylinder complications and pump malposition and can be extremely helpful to the surgeon in preoperative planning if revision is needed. After this review, the radiologist should be able to identify normal IPP components and their complications.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2019

Judging the J pouch: a pictorial review

Restorative total proctocolectomy with ileal pouch-anal anastomosis is the surgery of choice for patients with medically refractory ulcerative colitis, ulcerative colitis with high-grade dysplasia or multi-focal low-grade dysplasia, and for patients with familial adenomatous polyposis. The natural history of the surgery is favorable, and patients generally experience improved quality of life and acceptable long-term functional outcome. However, some patients experience significant long-term morbidity from early and/or late pouch-related complications. When complications arise, radiologists must understand the advantages and disadvantages of the various imaging modalities that can be used to assess the pouch. Radiologist familiarity with the surgical technique, pouch anatomy, and imaging appearance of the various potential early and late complications will help facilitate appropriate clinical and surgical decision-making. This review provides an anatomic-based imaging review of the pouch and pouch-related complications, including numerous illustrative fluoroscopic and cross-sectional imaging examples.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2019

Urinary diversions: a primer of the surgical techniques and imaging findings

Objective: The article attempts to describe the indications, classification, and surgical anatomy of the commonly performed urinary diversion procedures, followed by the imaging protocol and radiological appearances of the normal postoperative anatomy and complications related to these procedures. Contents: Diversion procedures are used to reroute urine after cystectomy and in patients with refractory neurogenic or outlet obstruction of the urinary bladder. Broadly, these can be classified as continent and incontinent diversions. Patients with urinary diversions frequently undergo radiological investigations for the detection of complications. Commonly, a loopogram or pouchogram is performed few weeks after the surgery to look for leak, whereas CT or MRI is used for long-term follow-up. Postoperative complications can be early (within 30 days of the surgery) or delayed and include leaks, collections, strictures, calculi, parastomal hernia, small bowel obstruction, and oncologic recurrence. Conclusion: A variety of urinary diversion procedures are commonly performed and interpretation of the postsurgical anatomy can be overwhelming for the general radiologist. This article provides a basic understanding of the normal anatomy as well as a thorough discussion on the imaging protocol and radiological appearances of the potential complications associated with these procedures.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2012

Irreversible Electroporation for Focal Ablation at the Porta Hepatis

Patients with chemotherapy-refractory liver metastases who are not candidates for surgery may be treated with focal ablation techniques with established survival benefits. Irreversible electroporation is the newest of these and has the putative advantages of a nonthermal action, preventing damage to adjacent biliary structures and bowel. This report describes the use of irreversible electroporation in a 61-year-old man with a solitary chemoresistant liver metastasis unsuitable for radiofrequency ablation as a result of its proximity to the porta hepatis. At 3 months, tumor size was decreased on computed tomography from 28 Multiplication-Sign 19 to 20 Multiplication-Sign 17 mm, representing stable disease according to the response evaluation criteria in solid tumors. This corresponded to a decrease in tumor volume size from 5.25 to 3.16 cm{sup 3}. There were no early or late complications. Chemoresistant liver metastases in the proximity of the porta hepatis that are considered to be too high a risk for conventional surgery or thermal ablation may be considered for treatment by the novel ablation technique of irreversible electroporation.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2013

Pancreaticoportal Fistula and Disseminated Fat Necrosis After Revision of a Transjugular Intrahepatic Portosystemic Shunt

A 59-year old man with alcohol related cirrhosis and portal hypertension was referred for transjugular intrahepatic portosystemic shunt (TIPS) to treat his refractory ascites. Ten years later, two sequential TIPS revisions were performed for shunt stenosis and recurrent ascites. After these revisions, he returned with increased serum pancreatic enzyme levels and disseminated superficial fat necrosis; an iatrogenic pancreaticoportal vein fistula caused by disruption of the pancreatic duct was suspected. The bare area of the TIPS was subsequently lined with a covered stent-graft, and serum enzyme levels returned to baseline. In the interval follow-up period, the patient has clinically improved.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2013

Bradycardia Associated With Drug-Eluting Beads Loaded With Irinotecan (DEBIRI) Infusion for Colorectal Liver Metastases

Intra-arterial injection of drug-eluting beads loaded with irinotecan (DEBIRI) is a new treatment option being investigated, with encouraging results, for unresectable colorectal liver metastases that are refractory to systemic chemotherapy (Martin et al., Ann Surg Oncol 18:192-198, 2011). Toxicity related to DEBIRI has also been described (Martin et al., Cardiovasc Intervent Radiol 33:960-966, 2010). Nevertheless, experience and literature related to DEBIRI remain limited, and experience with this treatment is expected to increase. The purpose of this article is to describe bradycardia occurring during DEBIRI administration, which has not been reported thus far.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2013

Radioembolization of the Spleen: A Revisited Approach for the Treatment of Malignant Lymphomatous Splenomegaly

Intraarterial administration of {sup 90}Y microspheres to the spleen in patients with malignant lymphoma was mentioned once in the literature in 1973. This case study illustrates the potential indication of selective internal radiotherapy in a heavily pretreated patient with highly refractory disease with a marginal zone lymphoma in leukemic phase and symptomatic splenomegaly. We describe the clinical course of disease; the biological and clinical response to the treatment after radioembolization; and simulation and dosimetry by multimodal imaging via single-photon emission computed tomography and computed tomography. The advantages of radioembolization for the management of lymphomatous splenomegaly are discussed.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2013

Is There a Role for Empiric Gastroduodenal Artery Embolization in the Management of Patients with Active Upper GI Hemorrhage?

PurposeTo assess the relative efficacy of empiric gastroduodenal artery (GDA) embolization in reducing recurrent hemorrhage compared to image-guided targeted embolization.MethodsData were retrospectively collected for consecutive patients who had catheter angiography for major upper gastrointestinal hemorrhage from May 2008 to November 2010 (n = 40). The total number of cases were divided into two main groups according to angiographic findings: those that demonstrated a site of hemorrhage on catheter angiography (group 1, n = 13), and those where the site of hemorrhage was not identified on catheter angiography (group 2, n = 27). Group 2 was then further divided into patients who received empiric embolization (group 2a, n = 20) and those who had no embolization performed after angiography (group 2b, n = 7).ResultsThe technical and clinical success rates for embolization in groups 1 and 2a were, respectively, 100 vs. 95 %, and 85 vs. 80 %. There was no statistical significance in the recurrent hemorrhage rate, reintervention rate, or 30 day mortality between targeted and empiric embolization groups. There were no complications attributed to embolization within this study cohort.ConclusionCases of duodenal-related major upper gastrointestinal hemorrhage where no embolization is performed have poor outcome. Empiric embolization of the GDA in patients with major upper gastrointestinal hemorrhage refractory to endoscopic treatment appears to be a safe and effective treatment, with low reintervention rates and good clinical outcome comparable to patients where the site of hemorrhage is localized and embolized with computed tomographic angiography or catheter angiography and embolized.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2013

Transjugular Intrahepatic Portosystemic Shunt for Treatment of Cirrhosis-related Chylothorax and Chylous Ascites: Single-institution Retrospective Experience

PurposeTo investigate the efficacy and safety of the use of transjugular intrahepatic portosystemic shunt (TIPS) creation to treat cirrhosis-related chylous collections (chylothorax and chylous ascites).MethodsWe retrospectively reviewed data from four patients treated for refractory cirrhosis-related chylous collections with TIPS at our institution over an 8 year period.ResultsOne patient had chylothorax, and three patients had concomitant chylothorax and chylous ascites. There were no major complications, and the only procedure-related complications occurred in two patients who had mild, treatable hepatic encephalopathy. All patients had improvement as defined by decreased need for thoracentesis or paracentesis, with postprocedure follow-up ranging from 19 to 491 days.ConclusionTIPS is a safe procedure that is effective in the treatment of cirrhosis-related chylous collections.

62 RADIOLOGY AND NUCLEAR MEDICINE↗