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All sources NASA NTRS DOE OSTI

DOE OSTI2022

Concurrent Enhancement of Acetylene Uptake Capacity and Selectivity by Progressive Core Expansion and Extra–Framework Anions in Pore–Space–Partitioned Metal–Organic Frameworks

A multi-stage core-expansion method is proposed here as one component of the integrative binding-site/extender/core-expansion (BEC) strategy. The conceptual deconstruction of the partitioning ligand into three editable parts draws our focus onto progressive core expansion and allows the optimization of both acetylene uptake and selectivity. Herein the effectiveness of this strategy is shown through a family of eight cationic pore-partitioned materials containing three different partitioning ligands and various counter anions. The optimized structure, Co 3 -cpt-tph-Cl (Hcpt=4-(p-carboxyphenyl)-1,2,4-triazole, H-tph=(2,5,8-tri-(4-pyridyl)-1,3,4,6,7,9-hexaazaphenalene) with the largest surface area and highest C 2 H 2 uptake capacity (200 cm 3 /g at 298 K), also exhibits (desirably) the lowest CO 2 uptake and hence the highest C 2 H 2 /CO 2 selectivity. The successful boost in both C 2 H 2 capacity and IAST selectivity allows Co 3 -cpt-tph-Cl to rank among the best crystalline porous materials, ionic MOFs in particular, for C 2 H 2 uptake and C 2 H 2 /CO 2 experimental breakthrough separation.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗

DOE OSTI2022

Recent Progress in Electrochemical Nitrogen Reduction on Transition Metal Nitrides

Distributed electrochemical nitrogen reduction reaction (ENRR) powered by renewable energy for the on-site production of ammonia is an attractive alternative to the industrial Haber–Bosch process, which is responsible for roughly 2 % of global energy consumption. Here, in this Review, we summarize recent progress in the ENRR catalyzed by transition metal nitrides (TMNs). The unique electronic structures of TMNs make them promising ENRR catalysts for active and selective ammonia production, which have been predicted theoretically and demonstrated experimentally. Reaction pathways and deactivation mechanisms of the ENRR on different TMNs are surveyed, and current understanding of structure-activity relations is discussed. To develop highly active, selective, and stable TMN catalysts for industrial-scale ENRR, membrane electrode assembly configuration is recommended in catalyst evaluation. Furthermore, we highlight the importance of developing mechanistic understanding on ENRR with different operando spectroscopic techniques.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗

DOE OSTI2023

Conducting Polymers Meet Lithium–Sulfur Batteries: Progress, Challenges, and Perspectives

Lithium–sulfur (Li–S) batteries have attracted increased interest because of the high theoretical energy density, low cost, and environmental friendliness. Conducting polymers (CPs), as one of the most promising materials used in Li–S batteries, can not only facilitate electron transfer and buffer the large volumetric change of sulfur benefiting from their porous structure and excellent flexibility, but also enable stronger physical/chemical adsorption capacity toward polysulfides (LiPSs) when doped with abundant heteroatoms to promote the sulfur redox kinetics and achieve the high sulfur loading. This review firstly introduces the properties of various CPs including structural CPs (polypyrrole (PPy), polyaniline (PANi), polyethylene dioxothiophene [PEDOT]) and compound CPs (polyethylene oxide (PEO), polyvinyl alcohol (PVA) and poly(acrylic acid) [PAA]), and their application potential in Li–S batteries. Furthermore, the research progress of various CPs in different components (cathode, separator, and interlayer) of Li–S batteries is systematically summarized. Finally, the application perspective of the CPs in Li–S batteries as a potential guidance is comprehensively discussed.

Chen, Xin↗

DOE OSTI2015

Recent progress on the development of biofuel cells for self-powered electrochemical biosensing and logic biosensing: A review

Biofuel cells (BFCs) based on enzymes and microorganisms have been recently received considerable attention because they are recognized as an attractive type of energy conversion technology. In addition to the research activities related to the application of BFCs as power source, we have witnessed recently a growing interest in using BFCs for self-powered electrochemical biosensing and electrochemical logic biosensing applications. Compared with traditional biosensors, one of the most significant advantages of the BFCs-based self-powered electrochemical biosensors and logic biosensors is their ability to detect targets integrated with chemical-to-electrochemical energy transformation, thus obviating the requirement of external power sources. Following my previous review (Electroanalysis 2012, 24, 197-209), the present review summarizes, discusses and updates the most recent progress and latest advances on the design and construction of BFCs-based self-powered electrochemical biosensors and logic biosensors. In addition to the traditional approaches based on substrate effect, inhibition effect, blocking effect and gene regulation effect for BFCs-based self-powered electrochemical biosensors and logic biosensors design, some new principles including enzyme effect, co-stabilization effect, competition effect and hybrid effect are summarized and discussed by me in details. The outlook and recommendation of future directions of BFCs-based self-powered electrochemical biosensors and logic biosensors are discussed in the end.

microorganisms↗

DOE OSTI2019

Research Progress of Mercury Bioaccumulation in the Aquatic Food Chain, China: A Review

Research on mercury (Hg) in aquatic ecosystems in China has focused mainly on fish, with little research on the base of the food chain and Hg bioaccumulation mechanisms. This paper summarizes research progress pertaining to the characteristics, current status, and trends of Hg accumulation in the aquatic food chain in China, analyzes the effects of human activities on the transmission and accumulation of Hg in aquatic food chains, and assesses their risks to human and ecosystem health. A comparison of fish samples in China between 2000 and 2018 indicates that their total Hg content remains at relatively safe levels. However, because current information is generally insufficient to confirm how anthropogenic activities affect transformation and bioaccumulation in the aqueous environment, Hg isotope studies should be a focus of research on aquatic food webs. Additionally, more attention should be paid to Hg transport and bioaccumulation in the basic food chain by focusing on multi-contaminant joint exposure studies and establishing Hg bio-transport models.

54 ENVIRONMENTAL SCIENCES↗

DOE OSTI2017

Embolotherapy for Neuroendocrine Tumor Liver Metastases: Prognostic Factors for Hepatic Progression-Free Survival and Overall Survival

PurposeThe purpose of the study was to evaluate prognostic factors for survival outcomes following embolotherapy for neuroendocrine tumor (NET) liver metastases.Materials and MethodsThis was a multicenter retrospective study of 155 patients (60 years mean age, 57 % male) with NET liver metastases from pancreas (n = 71), gut (n = 68), lung (n = 8), or other/unknown (n = 8) primary sites treated with conventional transarterial chemoembolization (TACE, n = 50), transarterial radioembolization (TARE, n = 64), or transarterial embolization (TAE, n = 41) between 2004 and 2015. Patient-, tumor-, and treatment-related factors were evaluated for prognostic effect on hepatic progression-free survival (HPFS) and overall survival (OS) using unadjusted and propensity score-weighted univariate and multivariate Cox proportional hazards models.ResultsMedian HPFS and OS were 18.5 and 125.1 months for G1 (n = 75), 12.2 and 33.9 months for G2 (n = 60), and 4.9 and 9.3 months for G3 tumors (n = 20), respectively (p < 0.05). Tumor burden >50 % hepatic volume demonstrated 5.5- and 26.8-month shorter median HPFS and OS, respectively, versus burden ≤50 % (p < 0.05). There were no significant differences in HPFS or OS between gut or pancreas primaries. In multivariate HPFS analysis, there were no significant differences among embolotherapy modalities. In multivariate OS analysis, TARE had a higher hazard ratio than TACE (unadjusted Cox model: HR 2.1, p = 0.02; propensity score adjusted model: HR 1.8, p = 0.11), while TAE did not differ significantly from TACE.ConclusionHigher tumor grade and tumor burden prognosticated shorter HPFS and OS. TARE had a higher hazard ratio for OS than TACE. There were no significant differences in HPFS among embolotherapy modalities.

62 RADIOLOGY AND NUCLEAR MEDICINE↗

DOE OSTI2025

Modeling of Precipitation over Africa: Progress, Challenges, and Prospects

In recent years, there has been an increasing need for climate information across diverse sectors of society. This demand has arisen from the necessity to adapt to and mitigate the impacts of climate variability and change. Likewise, this period has seen a significant increase in our understanding of the physical processes and mechanisms that drive precipitation and its variability across different regions of Africa. By leveraging a large volume of climate model outputs, numerous studies have investigated the model representation of African precipitation as well as underlying physical processes. These studies have assessed whether the physical processes are well depicted and whether the models are fit for informing mitigation and adaptation strategies. This paper provides a review of the progress in precipitation simulation over Africa in state-of-the-science climate models and discusses the major issues and challenges that remain.

CMIP6↗

DOE OSTI2016

Obtaining lower bounds from the progressive hedging algorithm for stochastic mixed-integer programs

We present a method for computing lower bounds in the progressive hedging algorithm (PHA) for two-stage and multi-stage stochastic mixed-integer programs. Computing lower bounds in the PHA allows one to assess the quality of the solutions generated by the algorithm contemporaneously. The lower bounds can be computed in any iteration of the algorithm by using dual prices that are calculated during execution of the standard PHA. In conclusion, we report computational results on stochastic unit commitment and stochastic server location problem instances, and explore the relationship between key PHA parameters and the quality of the resulting lower bounds.

97 MATHEMATICS AND COMPUTING↗

DOE OSTI2021

Progress of Divertor Heat and Particle Flux Control in EAST for Advanced Steady-State Operation in the Last 10 Years

Active control of the excessively high heat and particle fluxes on the divertor target plates is of fundamental importance to the steady state operation of tokamaks, especially for fusion reactors. A series of experiments have been carried out on this critical issue to relieve the plasma-wall interactions in the experimental advanced superconducting tokamak (EAST) in the last ten years, not only contributing to the long pulse operation of EAST itself, but also providing physical understandings and potential techniques to the next-generation devices like ITER. Here we have characterized the power deposition pattern and broadened the divertor footprint width effectively. The plasma-wetted area is actively handled using either 3-dimentional edge magnetic topology or advanced plasma equilibrium, thereby peak heat flux around the strike point is reduced. Active control of detachment or radiation compatible with core plasma performance has progressed significantly in very recent years, with a series of active feedback control modules developed and utilized successfully, based on the divertor physics advances with both experiments and simulation. The upper divertor of EAST was upgraded from graphite to active water-cooling ITER-like tungsten in 2014, exhibiting much enhanced heat removal capability. As for the particle exhaust including both fueling and impurity particles, in addition to wall conditioning and impurity source control, the efficiency of particle flux exhaust is optimized by making full use of the divertor closure and the plasma drifts in both scrape-off layer and divertor volume. These heat and particle exhaust advances contribute greatly to a series of EAST achievements like H-mode operation over 100 s. A brief near-term plan on the integrated control of divertor plasma-wall interactions in long-time scale will also be introduced, aiming to provide favorable divertor operation solution for ITER and CFETR.

70 PLASMA PHYSICS AND FUSION TECHNOLOGY↗

DOE OSTI2026

Progress in Extending the High-Temperature Plasma Regime in the LHD

In this paper, we show the expansion of the high-temperature regime and related physical phenomena in the Large Helical Device (LHD). At the LHD, we have developed a high-temperature operational regime for both ion (T i ) and electron (T e ) temperatures through understanding the physical characteristics of high-temperature plasma, the enhancement of plasma heating, and the development of technical methods such as wall recycling control and impurity control. In particular, the formation of the ion internal transport barrier (i-ITB) and electron internal transport barrier (e-ITB) in the plasma core region is the key to improving plasma performance. In addition, the deuterium experiment that began in 2017 showed that, due to the isotope effect, the thermal transport of both ions and electrons is suppressed in deuterium plasma compared to light hydrogen plasma, and that a high central temperature can be achieved efficiently. Furthermore, the combination of neutral beam injection (NBI) and electron cyclotron heating (ECH) has extended the operating conditions that simultaneously maintain high T i and T e , and comprehensive research on plasma confinement characteristics with an eye to future fusion reactor conditions has progressed.

Large Helical Device↗

DOE OSTI2018

Comparative Response of Indigenously Developed Bacterial Consortia on Progressive Degradation of Polyhydroxybutyrate Film Composites

The global demand of bioplastics has lead to an exponential increase in their production commercially. Hence, biodegradable nature needs to be evaluated in various ecosystems viz. air, water, soil and other environmental conditions to avoid the polymeric waste accumulation in the nature. In this paper, we investigated the progressive response of two indigenously developed bacterial consortia, i.e., consortium-I (C-I: Pseudomonas sp. strain Rb10, Pseudomonas sp. strain Rb11 and Bacillus sp. strain Rb18), and consortium-II (C-II: Lysinibacillus sp. strain Rb1, Pseudomonas sp. strain Rb13 and Pseudomonas sp. strain Rb19), against biodegradation behavior of polyhydroxybutyrate (PHB) film composites, under natural soil ecosystem (in net house). The biodegraded films recovered after 6 and 9 months of incubation were analyzed through Fourier transform infrared spectroscopy and scanning electron microscopy to determine the variations in chemical and morphological parameters (before and after incubation). Noticeable changes in the bond intensity, surface morphology and conductivity were found when PHB composites were treated with C-II. These changes were drastic in case of blends in comparison to copolymer. The potential isolates not only survived, but, also, there was a significant increase in bacterial diversity during whole period of incubation. To the best of our knowledge, it is the first report which described the biodegradation potential of Lysinibacillus sp. as a part of C-II with Pseudomonas sp. against PHB film composites.

54 ENVIRONMENTAL SCIENCES↗

DOE OSTI2018

Arak’s Inequalities for the Generalized Arithmetic Progressions

In 1980s, Arak has obtained powerful inequalities for the concentration functions of sums of independent random variables. Using these results, he has solved an old problem stated by Kolmogorov. In this paper, one of Arak’s results is modified to include generalized arithmetic progressions in the statement.

97 MATHEMATICS AND COMPUTING↗

DOE OSTI2017

Recent progress in thermoelectric nanocomposites based on solution-synthesized nanoheterostructures

Thermoelectric materials, which can convert waste heat into electricity, have received increasing interest in these years. This paper describes the recent progress in thermoelectric nanocomposite based on solution-synthesized nanoheterostructures. We start our discussion with the strategies of improving power factor of a given material by using nanoheterostructures. Then we discuss the methods of decreasing thermal conductivity. Finally, we highlight one way to decouple power factor and thermal conductivity, namely, incorporating phase-transition materials into a nanowire heterostructure. We have explored the lead telluride-copper telluride thermoelectric nanowire heterostructure in our group. Future possible ways to improve figure of merit are discussed at the end of this paper.

77 NANOSCIENCE AND NANOTECHNOLOGY↗

DOE OSTI2022

Overview of recent progress in 3D field physics in KSTAR

Various 3D field physics challenges of magnetically confined plasmas arise when the driving source comes from either externally applied non-axisymmetric 3D magnetic perturbations or plasma instabilities inside the plasma. Recently, several key outstanding topics of 3D field physics have been extensively studied in the Korean Superconducting Tokamak Advanced Research (KSTAR), such as edge-localized-mode (ELM) control by resonant magnetic perturbation (RMP), error field (EF) control, 3D field effects on rotation and transport, and RMP-induced alteration of divertor heat flux and detachment. KSTAR has a few physically unique features (i.e., high rotation and long-pulse plasmas with a low intrinsic EF) and machine/diagnostic capabilities (i.e., 3-row in-vessel control coil and state-of-the-art 2D/3D imaging diagnostics), which have been taken advantage of until now to address critical 3D field physics issues relevant to ITER and K-DEMO. Among many remarkable achievements are the robust access to and control of n = 1 RMP ELM suppression, along with a development of its physics basis tools, parameter expansion, optimization, and long-pulse control techniques. Nonetheless, a series of unresolved 3D physics themes, as well as limited coverage of 3D field operating regimes, have also been identified as future works for the 3D field research in KSTAR. In this paper, we provide an overview about the recent progress of KSTAR 3D field physics and present future plans of KSTAR 3D research toward a future fusion reactor.

3D field physics↗

DOE OSTI2021

Progress of Nanotechnology for Lithium-Sulfur Batteries

Lithium-Sulfur (Li-S) battery has been proposed and investigated since the 1960s as an effective energy storage device via reversible electrochemical reactions. As the fast development and commercialization of Li-ion battery (LIB) technology kept moving forward, no breakthroughs have been attained to solve critical technical issues facing Li-S batteries during the following decades. In the year 2000s, Li-S batteries reattracted significant interests in the research field owing to their low-cost advantages, high theoretical specific energy of 2600 Wh kg -1 , which is at least 3 times higher than the current LIB technology. The low-cost and high abundance of sulfur (i.e., the cathode active material), make Li-S batteries more appealing than LIBs given the fact that the latter use critical materials such as cobalt and nickel in the manufacturing of the cathodes. Moreover, the high-energy and low-cost features make the Li-S battery a promising energy storage technology in practical applications such as portable devices, electric vehicles, and grid storage when coupled with the harvesting of solar or wind renewable energies. For example, since 2007, SION Power Corporation (Tucson, USA) and Oxis Energy (UK) made progress towards the commercialization of Li-S batteries with products showing specific energies over 350 Wh kg -1 for powering electric vehicles. To be on a par with the current LIB technology, the ultimate goal of achieving 500 Wh kg -1 for Li-S battery will make it more competitive for widespread commercialization.

Li, Mengya↗

DOE OSTI2024

Progressive Hedging Decomposition for Solutions of Large-Scale Process Family Design Problems

Rapid, wide-scale deployment of green process systems, such as carbon capture or water desalination systems, is essential for combatting climate change. Methods relying on traditional design or modularity fail to capture the benefits of both economies of numbers and economies of scale. We have proposed process family design, which designs a family of processes simultaneously exploiting opportunities for common elements. In previous work, we explored different optimization formulations to solve this problem. In this work, we develop a decomposition approach to tackle larger problems efficiently. We solve a water desalination case study, which is too large to solve within a reasonable timeframe with the discretization formulation. We exploit the block angular structure of the discretization problem to decompose and solve using Progressive Hedging (PH). We use the open-source Python package mpi-sppy to execute PH which allows us to leverage parallelization and a HPC cluster to further improve solution time.

Stinchfield, Georgia↗

DOE OSTI2015

Progress in vacuum susceptibilities and their applications to the chiral phase transition of QCD

The QCD vacuum condensates and various vacuum susceptibilities are all important parameters which characterize the nonperturbative properties of the QCD vacuum. In the QCD sum rules external field formula, various QCD vacuum susceptibilities play important roles in determining the properties of hadrons. In this paper, we review the recent progress in studies of vacuum susceptibilities together with their applications to the chiral phase transition of QCD. The results of the tensor, the vector, the axial–vector, the scalar, and the pseudo-scalar vacuum susceptibilities are shown in detail in the framework of Dyson–Schwinger equations.

71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗

DOE OSTI2012

miR-1297 mediates PTEN expression and contributes to cell progression in LSCC

Highlights: Black-Right-Pointing-Pointer miR-1297 was found to be overexpressed in LSCC and contribute to the cell progression. Black-Right-Pointing-Pointer PTEN was confirmed to be a target gene of miR-1297. Black-Right-Pointing-Pointer Downregulation of PTEN can rescue the proliferation and invasion ability of miR-1297 downregulated Hep-2 cells. Black-Right-Pointing-Pointer Downregulation of miR-1297 inhibits tumor growth in vivo. -- Abstract: MicroRNAs (miRNAs) are small noncoding RNAs that regulate gene expression after transcription, and are involved in cancer development. Laryngeal squamous cell carcinoma (LSCC) is one of the most common malignant neoplasms with increasing incidence in recent years. In this paper, we report the overexpression of miR-1297 in LSCC and Hep-2 cells. In addition, PTEN was identified to be directly regulated by miR-1297 through western blot and luciferase activity assay. Furthermore, downregulation of miR-1297 in Hep-2 cells was shown to inhibit cancer cell proliferation, migration, and tumor genesis. Our results document a new epigenetic mechanism for PTEN regulation in LSCC, which is crucial for the development of these tumors.

60 APPLIED LIFE SCIENCES↗