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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 487 records · Page 27
All sourcesNASA NTRSDOE OSTI
NASA NTRSDate not supplied

Target Tracking with Distributed Sensing and Optimal Data Migration

The paper presents an Extended Kalman Filter based framework for airborne target tracking using adaptive information fusion from multi-modal multi-rate distributed sensors network. First, the tracking algorithm execution location is determined using an optimal data migration strategy, which also computes the associated delays for each sensor data to arrive at the computing location. Next, the fast (zero-delay) sensors information is dynamically fused in the filter correction procedure at the arrival instance of each valid sensor reading. Finally, the target estimation is updated based on the valid slow (delayed) data, which are grouped according to the delay-time steps before application of the Larsen's method. This approach is applied to the synthetic sensor data generated by means of the ground based radar and camera models for the simulated target flight in Reflection simulation environment.

Distributed sensing↗
NASA NTRSDate not supplied

Target Tracking with Distributed Sensing and Optimal Data Migration

The paper presents an Extended Kalman Filter based framework for airborne target tracking using adaptive information fusion from multi-modal multi-rate distributed sensors network. First, the tracking algorithm execution location is determined using an optimal data migration strategy, which also computes the associated delays for each sensor data to arrive at the computing location. Next, the fast (zero-delay) sensors information is dynamically fused in the filter correction procedure at the arrival instance of each valid sensor reading. Finally, the target estimation is updated based on the valid slow (delayed) data, which are grouped according to the delay-time steps before application of the Larsen's method. This approach is applied to the synthetic sensor data generated by means of the ground based radar and camera models for the simulated target flight in Reflection simulation environment.

Distributed sensing↗
DOE OSTI2018

Numerical Modelling of Radionuclide Migration in the Context of a Near-Surface LILW Disposal Facility - 18618

The reference solution for the management of low and intermediate level short-lived waste (LILW) in France consists in their emplacement in concrete vaults built at the near-surface. The corresponding disposal facility under operation by the French waste management organization (Andra), is located in North-eastern France and planned to be closed in 2060. The safety case developed by Andra has to show the evidence that, amongst other aspects, the radionuclide transfer through the confinement barriers will occur in such a way that the human and environmental exposure will be as low as reasonably achievable (ALARA) and in accordance with the dose constraints. For this purpose, modelling is used to integrate uncertainties about the characteristics of concrete components, waste and water table and their evolution in time and space. At last, modelling is finally used to investigate the radiological impact of specific scenarios in which the failure of safety barriers occurs. In the frame of its technical review of the safety assessment, the French Institute for Radiological Protection and Nuclear Safety (IRSN) also performs such kind of numerical modelling of radionuclide fate from the waste to the hydrogeological outlets, in order to check whether the assessment performed by Andra takes into account sufficiently conservative assumptions. The present work aims to evaluate the role of components of the vaults on radionuclide transport during the post-closure period over a few thousand years. For this purpose, IRSN carries out numerical calculations with MELODIE software, which simulates water flow and transport of species, in order to simulate radionuclide migration from waste packages emplaced in a concrete vault to the surrounding groundwater. The developed transport model focuses on 3-H radionuclide and integrates Andra's main assumptions (release model from the waste packages, chemical and hydraulic properties of the vault components, shrinkage and cracks in concrete components). An adaptive mesh method, based on an a posteriori error estimator, was used to model the cracks and the consideration of a strong heterogeneity in the hydraulic and transport parameters values in the different components of the model. This method shows an improvement of results of about 40 times, whereas the mesh size was increased by only 2%. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2023

Imaging Light‐Induced Migration of Dislocations in Halide Perovskites with 3D Nanoscale Strain Mapping

Abstract In recent years, halide perovskite materials have been used to make high‐performance solar cells and light‐emitting devices. However, material defects still limit device performance and stability. Here, synchrotron‐based Bragg coherent diffraction imaging is used to visualize nanoscale strain fields, such as those local to defects, in halide perovskite microcrystals. Significant strain heterogeneity within MAPbBr 3 (MA = CH 3 NH 3 + ) crystals is found in spite of their high optoelectronic quality, and both 〈100〉 and 〈110〉 edge dislocations are identified through analysis of their local strain fields. By imaging these defects and strain fields in situ under continuous illumination, dramatic light‐induced dislocation migration across hundreds of nanometers is uncovered. Further, by selectively studying crystals that are damaged by the X‐ray beam, large dislocation densities and increased nanoscale strains are correlated with material degradation and substantially altered optoelectronic properties assessed using photoluminescence microscopy measurements. These results demonstrate the dynamic nature of extended defects and strain in halide perovskites, which will have important consequences for device performance and operational stability.

36 MATERIALS SCIENCE↗
DOE OSTI2021

Ultrahigh-Rate and Long-Life Zinc–Metal Anodes Enabled by Self-Accelerated Cation Migration

Aqueous zinc ion batteries are receiving unprecedented attention owing to their markedly high safety and sustainability, yet their lifespan particularly at high rates is largely limited by the poor reversibility of zinc (Zn) metal anodes, due to the random ion diffusion and sluggish ion replenishment at reaction interface. In this work, we propose a tunnel-rich and corona-poled ferroelectric thin film coating for Zn metal anode to tackle above conundra. It is demonstrated that the poled ferroelectric coating can better deconcentrate and self-accelerate ion migration at coating/Zn interface upon electroplating process than untreated ferroelectric coating and bare Zn, thus enabling a compact and horizontally-aligned Zn morphology even at ultrahigh rates. Notably, a maximal cumulative plating capacity of over 6500 mAh cm -2 (at 10 mA cm -2 ) is achieved for the surface-modified Zn metal anode, showing extraordinary reversibility of Zn plating/stripping. This work provides new insights in stabilizing Zn metal electrodeposition at the scale of interfacial ion diffusion.

77 NANOSCIENCE AND NANOTECHNOLOGY↗
DOE OSTI2026

Identification of a key water molecule involved in the macrophage migration inhibitory factor‐catalyzed tautomerization of para ‐hydroxyphenylpyruvate using neutron crystallography

Abstract Neutron crystallography was used to determine a 2.5‐Å resolution all‐atom structure of macrophage migration inhibitory factor (MIF) interacting with 3‐(4‐hydroxyphenyl)‐pyruvate (HPP). MIF is a pro‐inflammatory, pro‐tumorigenic protein that may be an attractive therapeutic target. MIF catalyzes the interconversion of the keto and enol forms of HPP by a tautomerase reaction. Although HPP is evidently not a physiological substrate of MIF, many compounds that inhibit this activity in enzymatic assays have been found also to inhibit physiological activities of MIF. Therefore, the MIF‐catalyzed HPP tautomerization reaction is used in initial screening of compounds in the search for inhibitors of MIF physiological activity. The neutron diffraction‐derived crystal structure reveals the position of a water molecule involved in the tautomerization reaction, and also confirms the charged state of lysine‐32 in the active site. The structure confirms the previously proposed catalytic mechanism of MIF, with the N‐terminal Pro‐1 abstracting a proton to generate an HPP enolate intermediate which is subsequently protonated. The structure reported herein reveals that this proton is supplied by a neighboring water molecule. Along with the neutron structure, a room‐temperature synchrotron x‐ray crystal structure reveals a covalent adduct between HPP and MIF. While this adduct is a result of radiation‐induced chemistry, its formation confirms the catalytic role of the active site residue because a covalent complex could only form if the reactive carbon of the substrate is correctly positioned by the enzyme.

Schröder, Gabriela C. [Department of Molecular and↗
DOE OSTI2022

The effect of Cr alloying on defect migration at Ni grain boundaries

Mass transport along grain boundaries in alloys depends not only on the atomic structure of the boundary, but also its chemical make-up. In this work, we use molecular dynamics to examine the effect of Cr alloying on interstitial and vacancy-mediated transport at a variety of grain boundaries in Ni. We find that, in general, Cr tends to reduce the rate of mass transport, an effect which is greatest for interstitials at pure tilt boundaries. However, there are special scenarios in which it can greatly enhance atomic mobility. Cr tends to migrate faster than Ni, though again this depends on the structure of the grain boundary. Further, grain boundary mobility, which is sometimes pronounced for pure Ni grain boundaries, is eliminated on the time scales of our simulations when Cr is present. We conclude that the enhanced transport and grain boundary mobility often seen in this system in experimental studies is the result of non-equilibrium effects and is not intrinsic to the alloyed grain boundary. These results provide new insight into the role of grain boundary alloying on transport that can help in the interpretation of experimental results and the development of predictive models of materials evolution.

36 MATERIALS SCIENCE↗
DOE OSTI2017

Mathematical Simulation of the Migration of Radionuclides in a Soil Medium Under Nonisothermal Conditions with Account for Catalytic Microparticles and Nonlinear Processes

The problem of mathematical simulation of the vertical migration of radionuclides in a catalytic porous medium under nonisothermal conditions is considered. A numerical solution of the corresponding one-dimensional nonlinear boundary-value problem is obtained by the finite difference method. Numerical experiments are carried out and their analysis is made.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2019

Circular RNA expression and circPTPRM promotes proliferation and migration in hepatocellular carcinoma

Circular RNAs (circRNAs) play a critical role during hepatocellular carcinoma (HCC) development. CircRNA PTPRM (circPTPRM) has not been reported to cause disease and its role in HCC is unclear. This study explored circRNA expression and the function of circPTPRM in HCC. RNA sequencing (RNA-seq) was performed on 3 randomly selected pairs of HCC tissues and their corresponding adjacent non-tumor tissues. Three differentially expressed circRNAs, circPTPRM, circSMAD2 and circPTBP3 were selected and verified by real-time quantitative reverse transcription-polymerase chain reactions in 30 pairs of tissue samples, In vitro cultured hepatoma cells, and normal liver cells. Clinical data analysis was performed to select target circRNAs. Anti-target circRNA siRNAs were transfected into hepatoma cell lines, and the biological behavior of hepatoma cells following silencing of the target circRNA were detected by cell proliferation, plate cloning, and transwell assays. There were 86 differentially expressed circRNAs from RNA-seq, of which 53 were significantly upregulated and 33 were significantly downregulated in HCC. CircPTPRM expression was significantly upregulated in HCC tissue (p = 0.023) based on the analysis of 30 paired samples. CircPTPRM expression positively correlated with HCC recurrence and metastasis (p = 0.039). CircPTPRM silencing reduced HCC cell proliferation, migration and invasion. CircRNAs were differentially expressed in HCC samples. CircPTPRM was significantly upregulated in HCC and may function during the tumorigenesis and metastasis of HCC.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2022

Vacancy formation energies and migration barriers in multi-principal element alloys

Multi-principal element alloys (MPEAs) continue to garner interest as structural and plasma-facing materials due to their structural (phase) stability and increased resistance to radiation damage. Despite sensitivity of mechanical behavior to irradiation and point-defect formation, there has been scant attention on understanding vacancy stability and diffusion in refractory-based MPEAs. Using density-functional theory, we examine vacancy stability and diffusion barriers in body-centered cubic (Mo 0.95 W 0.05 ) 0.85 Ta 0.10 (TiZr) 0.05 . The results in this MPEA show strong dependence on environment, originating from local lattice distortion associated with charge-transfer between neighboring atoms that vary with different chemical environments. We find a correlation between degree of lattice distortion and migration barrier: (Ti, Zr) with less distortion have lower barriers, while (Mo, W) with larger distortion have higher barriers, depending up local environments. Under irradiation, our findings suggest that (Ti, Zr) are significantly more likely to diffuse than (Mo, W) while Ta shows intermediate effect. Finally, material degradation caused by vacancy diffusion can be controlled by tuning composition of alloying elements to enhance creep strength at extreme operating temperatures and harsh conditions.

36 MATERIALS SCIENCE↗
DOE OSTI2026

Migration of Al within dealuminated beta extruded catalysts influences olefin distribution during ethanol upgrading

Zeolites serve as essential catalytic platforms for many industrial processes, including emerging ethanol-to-olefins (ETO) upgrading technologies. Although metal-loaded (Cu, Zn, Y) dealuminated beta (deAlBeta) zeolite powders are promising catalysts for direct ETO conversion with high selectivity to butene-rich C3+ olefins necessary for production of sustainable aviation fuels (SAF), development of these materials as shaped technical bodies through the incorporation of binders is required for scale-up and commercial viability. Here, we report the ethanol upgrading performance of Cu-Zn-Y/deAlBeta extruded catalysts formulated with either alumina or kaolin clay binders. Both extrudates exhibit high ethanol dehydration reactivity which competes with the initial ethanol dehydrogenation step in the direct ETO reaction network. Consequently, elevated selectivity to dehydration side products (ethylene, diethyl ether) at ∼100% ethanol conversion is observed on Cu-Zn-Y/deAlBeta extrudates compared to the powder catalyst, which inhibits production of desired C3+ olefins. Utilizing microscopy and spectroscopic characterizations, we attribute this to Al migration from binder to zeolite particles within the extrudates, thus re-aluminating the zeolite and generating Brønsted acid sites active for dehydration reactions. This work elucidates the effects of binder incorporation on ETO product distributions and emphasizes that binder selection must be carefully considered during design of extruded zeolite catalysts.

Jacobs, Hunter [ORNL] (ORCID:000000016190874X)↗
DOE OSTI2018

Scavenger receptor class B type 1 regulates neuroblastoma cell proliferation, migration and invasion

Neuroblastoma (NB) is an extra cranial pediatric embryonal tumor most prevalent in children less than 1 year of age. NB accounts for 7% of all pediatric cancers but accounts for 15% of all childhood cancer deaths. Scavenger receptor class B type 1 (SR-B1), a mediator of cellular cholesterol uptake, is overexpressed in and have been linked to the aggressiveness of many cancers. Nevertheless, no studies have so far investigated the relationship between SR-B1 and NB. Elucidation of receptors that promote NB may pave the way for discovery of new therapeutic targets. Here we show that inhibition of SR-B1 reduced cell survival, migration and invasion, and cholesterol content in NB cell lines. Additionally analysis of SR-B1 levels in NB patient biopsies using the R2: Genomics Analysis and Visualization Platform showed that high SR-B1 expression correlated with decreased overall and event-free survival.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2018

MAD2-p31comet axis deficiency reduces cell proliferation, migration and sensitivity of microtubule-interfering agents in glioma

Mitotic arrest deficient-like-1 (MAD2, also known as MAD2L1) is thought to be an important spindle assembly checkpoint protein, which ensures accurate chromosome segregation and is closely associated with poor prognosis in many cancer. As a MAD2 binding protein, p31{sup comet} counteracts the function of MAD2 and leads to mitotic checkpoint silence. In this study, we explore the function of MAD2-p31{sup comet} axis in malignant glioma cells. Our results showed that disruption of MAD2-p31{sup comet} axis by MAD2 knockdown or p31{sup comet} overexpression suppressed cell proliferation, survival and migration of glioma, indicating that MAD2-p31{sup comet} axis is required for maintaining glioma cells malignancy. It is noted that MAD2 depletion or p31{sup comet} overexpression reduced the sensitivity of glioma cells to microtubule-interfering agents paclitaxel and vinblastine, providing clinical guidance for application of such drugs. Taken together, our findings suggest that MAD2-p31{sup comet} axis may serve as a potential therapeutic target for glioma.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2018

PUM1 promotes ovarian cancer proliferation, migration and invasion

Highlights: • This is the first investigation about PUM1 gene function in ovarian cancer. • PUM1 levels were significantly higher in ovarian cancer than in normal tissues. • PUM1 induces ovarian cancer cell growth, migration, and invasion in vitro. Abnormal expression of the PUM1 gene (pumilio RNA binding family member 1) is closely related to chromosomal mutations and carcinogenesis. However, there is no report about expression or function of PUM1 in ovarian cancer. The present study explored the role of PUM1 in the development and progression of ovarian cancer.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2018

Speckle-type POZ protein suppresses hepatocellular carcinoma cell migration and invasion via ubiquitin-dependent proteolysis of SUMO1/sentrin specific peptidase 7

Highlights: • SPOP expression was significantly downregulated in HCC and was associated with tumor size, differentiation and metastasis. • Low SPOP expression was a risk factor related to the prognosis of HCC patients. • SPOP inhibited HCC metastasis through interacting with SENP7 and promoting its degradation. Hepatocellular carcinoma (HCC) is associated with high metastatic potential and high mortality. Accumulating evidence has demonstrated that speckle-type POZ protein (SPOP) is a key adaptor molecule of ubiquitination. However, the molecular mechanism of SPOP-mediated ubiquitination in HCC metastasis remains obscure. In the present study, our results indicated that SPOP expression was significantly downregulated in HCC and was associated with tumor size, differentiation and metastasis. Cox regression model showed that low SPOP expression was a risk factor related to the prognosis of HCC patients. Loss- and gain-of-function assays demonstrated that SPOP inhibited HCC cell migration and invasion in vitro. Mechanisitically, co-immunoprecipitation and ubiquitination assays revealed that SPOP recognized and bound SENP7 and promoted its degradation via ubiquitin-dependent proteolysis. Analysis of immunohistochemistry showed that vimentin expression was correlated negatively with SPOP and positively with SENP7. These results implied that increased degradation of SENP7 by overexpression of SPOP decreased vimentin levels, which in turn attenuated HCC cell metastasis. Moreover, in vivo assays showed that SPOP overexpression also significantly suppressed liver and lung metastases. In summary, SPOP inhibits HCC cell metastasis via ubiquitin-dependent SENP7 proteolysis and may thus serve as a new opinion for the prevention of HCC metastasis.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2018

Circular RNA hsa{sub c}irc{sub 0}008039 promotes breast cancer cell proliferation and migration by regulating miR-432-5p/E2F3 axis

As the development of sequencing technology, more and more circular RNAs (circRNAs) are identified in human cancer tissues. Increasing evidences imply circRNAs are important regulators in tumor progression. Nevertheless, how circRNAs participate in breast cancer development and progression is not well understood. In the present study, we identified a novel circRNA hsa{sub c}irc{sub 0}008039 with upregulated expression level in breast cancer tissues. By functional experiments, we found that hsa{sub c}irc{sub 0}008039 depletion significantly suppressed the proliferation, arrested cell-cycle progression and reduced migration in breast cancer. Mechanistic investigations suggested that hsa{sub c}irc{sub 0}008039 served as a competing endogenous RNA (ceRNA) of miR-432-5p. Subsequently, E2F3 was identified as the functional target of miR-432-5p and overexpression of hsa{sub c}irc{sub 0}008039 elevated E2F3 expression in breast cancer. On the whole, our study indicated that hsa{sub c}irc{sub 0}008039 exerted oncogenic roles in breast cancer and suggested the hsa{sub c}irc{sub 0}008039/miR-432-5p/E2F3 axis might be a potential therapeutic target.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2018

LRP4 promotes proliferation, migration, and invasion in papillary thyroid cancer

Dysregulation of cell proliferation and death is considered the foundation of the malignant biological characteristics of cancer. In this study, we conducted a comprehensive analysis of a massively parallel whole transcriptome resequencing of paired papillary thyroid cancer and normal thyroid tissues from 19 patients. In addition, we found that LRP4, a member of the low-density lipoprotein receptor-related protein family, is significantly overexpressed in thyroid carcinoma. We demonstrated through quantitative real-time polymerase chain reaction (qRT-PCR) that LRP4 is upregulated in papillary thyroid cancer (PTC) tissues. This observation was also consistent with data analyzed from The Cancer Genome Atlas (TCGA) cohort. Thus, the biological role of LRP4 in the thyroid cancer in the present study was investigated using the PTC cell lines TPC1, BCPAP and KTC-1. In these cell lines, the mRNA level of LRP4 was higher than normal thyroid cancer cell named HTORI3. In vitro experiments demonstrated that LRP4 downregulation significantly inhibited the colony formation, proliferation, migration, and invasion of the three PTC cell lines. Knockdown of LRP4 by small interfering RNA (siRNA) in those cell lines decreased the protein expression of N-cadherin, Enhancer of zeste homolog 2 (EZH2), and Zinc finger E-box-binding home-box 1 (ZEB1). Furthermore, LRP4 knockdown significantly reduced the levels of phosphorylated PI3K in the PTC cell lines. In conclusion, the present study indicated that LRP4 is a gene associated with PTC and might become a potential therapeutic target.

60 APPLIED LIFE SCIENCES↗