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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 1,405 records · Page 78
All sourcesNASA NTRSDOE OSTI
DOE OSTI2018

Distinct non-invasive evaluation values of tumor-derived cell-free microRNAs, circulating microvesicles and exosomal microRNAs after renal carcinoma cryoablation

Highlights: • Circulating components could be used for the non-invasive evaluation of renal tumor cryoablation therapeutic effects. • Different circulating components have distinct roles in the evaluation of renal tumor cryoablation. • Exosomal microRNAs may be more suitable for the early postoperative judgment of tumor elimination effects. The detection of peripheral circulating tumor-derived components, such as cell-free microRNAs, circulating microvesicles, and exosomal microRNAs, has been shown as a promising noninvasive strategy. However, the different roles of these components in tumor therapy evaluations have remained largely undefined. In this paper, we employed an in vivo model of the human clear cell renal cell carcinoma line Caki-1-bearing mice to evaluate the therapeutic effects of cryoablation, which is a new minimally invasive treatment for renal cell carcinoma. At different times after cryoablation, we found that the levels of the cell-free microRNAs miR-122, miR-155 and miR-210 were first increased and then decreased. Additionally, the number of large-sized microvesicles was increased after cryoablation, but the number of small-sized circulating microvesicles did not change. Furthermore, the exosomal microRNAs miR-126–3p, miR-17–5p, and miR-21–3p rapidly decreased one day after cryoablation, an effect that was well correlated with the treatment degree. Therefore, we suggest that these circulating components may have different levels of importance in the evaluation of the efficacy of renal cell cryoablation, furthermore, exosomal microRNAs may be more suitable for the early postoperative judgment of tumor elimination effects, which are worth further exploration in clinical practice.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2020

Catalytic direct conversion of ethane to value-added chemicals under microwave irradiation

The reaction mechanism of ethane conversion over 4 % Mo-0.5 % Fe/ZSM-5 catalyst was investigated using two different reactors with different heating modes. A microwave fixed-bed reactor (MWFB) was used and its performance was compared to a conventional thermal fixed-bed reactor (CTFB). Over 80 % ethane conversion was achieved under microwave irradiation mode at 375 °C. Here, to achieve the same ethane conversion conventionally, the reaction temperature had to be elevated to 660 °C in the CTFB. The formation rates and selectivity of the products were compared under these two heating methods. The CTFB products had a higher selectivity towards aromatic compounds; whereas, the MWFB products had a higher selectivity towards ethylene; 26.5 % higher than the CTFB. Carbon analysis over spent catalysts of CTFB showed three distinct types of coke, whereas the microwave resulted in a single higher temperature coke type.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2016

The value of continuity: Refined isogeometric analysis and fast direct solvers

Here, we propose the use of highly continuous finite element spaces interconnected with low continuity hyperplanes to maximize the performance of direct solvers. Starting from a highly continuous Isogeometric Analysis (IGA) discretization, we introduce C0-separators to reduce the interconnection between degrees of freedom in the mesh. By doing so, both the solution time and best approximation errors are simultaneously improved. We call the resulting method “refined Isogeometric Analysis (rIGA)”. To illustrate the impact of the continuity reduction, we analyze the number of Floating Point Operations (FLOPs), computational times, and memory required to solve the linear system obtained by discretizing the Laplace problem with structured meshes and uniform polynomial orders. Theoretical estimates demonstrate that an optimal continuity reduction may decrease the total computational time by a factor between p 2 and p 3 , with pp being the polynomial order of the discretization. Numerical results indicate that our proposed refined isogeometric analysis delivers a speed-up factor proportional to p 2 . In a 2D mesh with four million elements and p=5, the linear system resulting from rIGA is solved 22 times faster than the one from highly continuous IGA. In a 3D mesh with one million elements and p=3, the linear system is solved 15 times faster for the refined than the maximum continuity isogeometric analysis.

97 MATHEMATICS AND COMPUTING↗
DOE OSTI2024

Advancing equitable value chains for the global hydrogen economy

Hydrogen is a rapidly growing focus for countries seeking to develop green industries, but there are many questions about how the nascent global hydrogen economy will develop, and what this implies for equitable sharing of benefits and burdens between nations. In this perspective we summarize emerging trends in national hydrogen strategies and develop recommendations for researchers and policymakers to center equity in hydrogen development. This will require integrating innovation and development perspectives on international technology transfer, developing more detailed representation of hydrogen trade in systems models, building equity considerations into national and international planning processes, and establishing robust technology transfer efforts. In conclusion, policymakers will also need to grapple with the difficulties of verifying life cycle emissions of hydrogen if hydrogen trade emerges as a significant trend, potentially requiring new methods of emissions accounting and trade reforms that prioritize international equity.

08 HYDROGEN↗
DOE OSTI2017

The Value of CCS under Current Policy Scenarios: NDCs and Beyond

This paper describes preliminary results of analysis using the Global Change Assessment Model (GCAM) to evaluate the potential role of CCS in addressing emissions reduction targets. Scenarios are modelled using the Paris-Increased Ambition (PIA) case developed by Fawcett et al. (2015), and a more aggressive Paris Two-Degree Ambition (P2A) case. Both cases are based upon nationally determined contributions (NDCs) agreed to at the UNFCCC Conference of Parties (COP-21) in December 2015, coupled with additional mitigation effort beyond the 2030 Paris timeframe, through the end of the century. Analysis of CCS deployment and abatement costs under both policy scenarios suggests that, as modelled, having CCS in the technological portfolio could reduce the global cost of addressing emissions reduction targets specified under the policy scenario by trillions of dollars, primarily by enabling a smoother and lower-cost transition to next-generation technologies. Through the end of the century, total global abatement costs associated with the PIA case – with five percent annual reduction in emission intensity and reaching 2.2 degrees by 2100 – are reduced by $15 trillion USD in the scenario where CCS is available to deploy by 2025 and remains available through 2100, reflecting a 47 percent savings in the cost of climate change abatement. Under the more ambitious P2A case, with 8 percent annual reduction in emission intensity and reaching 1.9 degrees by 2100, the availability of CCS reduces global abatement costs by $22 trillion USD through the end of the century, again nearly halving the costs of addressing the policy, relative to achieving the same target using an energy portfolio that does not include CCS. PIA and P2A scenarios with CCS result in 1,250 and 1,580 GtCO2 of global geologic storage by the end of the century, respectively.

29 ENERGY PLANNING, POLICY, AND ECONOMY↗