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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 1,729 records · Page 96
All sourcesNASA NTRSDOE OSTI
DOE OSTI2020

Economizing on Precious Metals in Three‐Way Catalysts: Thermally Stable and Highly Active Single‐Atom Rhodium on Ceria for NO Abatement under Dry and Industrially Relevant Conditions**

Abstract We show for the first time that atomically dispersed Rh cations on ceria, prepared by a high‐temperature atom‐trapping synthesis, are the active species for the (CO+NO) reaction. This provides a direct link with the organometallic homogeneous Rh I complexes capable of catalyzing the dry (CO+NO) reaction. The thermally stable Rh cations in 0.1 wt % Rh 1 /CeO 2 achieve full NO conversion with a turn‐over‐frequency (TOF) of around 330 h −1 per Rh atom at 120 °C. Under dry conditions, the main product above 100 °C is N 2 with N 2 O being the minor product. The presence of water promotes low‐temperature activity of 0.1 wt % Rh 1 /CeO 2 . In the wet stream, ammonia and nitrogen are the main products above 120 °C. The uniformity of Rh ions on the support, allows us to detect the intermediates of (CO+NO) reaction via IR measurements on Rh cations on zeolite and ceria. We also show that NH 3 formation correlates with the water gas shift (WGS) activity of the material and detect the formation of Rh hydride species spectroscopically.

Khivantsev, Konstantin↗
DOE OSTI2016

An air-stable Na 3 SbS 4 superionic conductor prepared by a rapid and economic synthetic procedure

All-solid-state sodium batteries, using abundant sodium resources and solid electrolyte, hold much promise for safe, low cost, large-scale energy storage. To realize the practical applications of all solid Na-ion batteries at ambient temperature, the solid electrolytes are required to have high ionic conductivity, chemical stability, and ideally, easy preparation. Ceramic electrolytes show higher ionic conductivity than polymers, but they often require extremely stringent synthesis conditions, either high sintering temperature above 1000 C or long-time, low-energy ball milling. Herein, we report a new synthesis route for Na 3 SbS 4 , a novel Na superionic conductor that needs much lower processing temperature below 200 C and easy operation. This new solid electrolyte exhibits a remarkable ionic conductivity of 1.05 mS cm -1 at 25 °C and is chemically stable under ambient atmosphere. In conclusion, this synthesis process provides unique insight into the current state-of-the-art solid electrolyte preparation and opens new possibilities for the design of similar materials.

25 ENERGY STORAGE↗
DOE OSTI2016

An assessment of the potential products and economic and environmental impacts resulting from a billion ton bioeconomy

This study is the summation of several analyses to assess the size and benefits of a Billion Ton Bioeconomy, a vision to enable a sustainable market for producing and converting a billion tons of US biomass to bio-based energy, fuels, and products by 2030. Two alternative biomass availability scenarios in 2030, defined as the (i) Business-as-usual (598 million dry tons) and (ii) Billion Ton (1042 million dry tons), establish a range of possible outcomes for the future bioeconomy. The biomass utilized in the current (2014) (365 million dry tons) economy is estimated to displace approximately 2.4% of fossil energy consumption and avoid 116 million tons of CO 2 -equivalent (CO 2 e) emissions, whereas the Billion Ton bioeconomy of 2030 could displace 9.5% of fossil energy consumption and avoid as much as 446 million tons of CO 2 equivalent emissions annually. Developing the integrated systems, supply chains, and infrastructure to efficiently grow, harvest, transport, and convert large quantities of biomass in a sustainable way could support the transition to a low-carbon economy. Bio-based activities in the current (2014) economy are estimated to have directly generated more than 48 billion in revenue and 285 000 jobs. Our estimates show that developing biomass resources and addressing current limitations to achieve a Billion Ton bioeconomy could expand direct bioeconomy revenue by a factor of 5 to contribute nearly 259 billion and 1.1 million jobs to the US economy by 2030.

29 ENERGY PLANNING, POLICY, AND ECONOMY↗
DOE OSTI2022

Techno‐economic assessment of single‐stream feedstock logistics supply chain for corn stover and grain

Abstract The state‐of‐technology for corn stover harvest is a multi‐pass system that collects the stover after grain harvest. An alternative is a single‐stream system where the grain and stover are harvested as a bulk material co‐stored and preserved by anerobic fermentation, and finally, co‐transported to a biorefinery. In the present work, four single‐pass whole‐plant bulk systems were compared with a conventional multi‐pass bale system. The single‐stream systems consisted of the harvest of corn grain and a portion of the stover fraction. Four machine configurations were simulated. This work predicted that a multi‐pass bale system would result in a material cost of 111.80 $2021 Mg –1 stover DM delivered to the biorefinery gate. Alternatively, the lowest cost single‐stream system was the self‐propelled forage harvester (SPFH) configured with the whole‐plant header, which delivered feedstock for 74.76 $2021 Mg stover DM –1 . In addition to machine configuration, a sensitivity analysis was performed to understand important drivers of feedstock cost. These analyses revealed that feedstock cost increased with moisture content, fertilizer price, and biorefinery size, and decreased with harvest season length, crop yield, and grower participation. This work demonstrated that single‐stream systems could reduce corn stover feedstock costs in comparison with state‐of‐technology systems. © 2022 The Authors. Biofuels, Bioproducts and Biorefining published by Society of Industrial Chemistry and John Wiley & Sons Ltd.

09 BIOMASS FUELS↗
DOE OSTI2024

Artificial ground reflector size and position effects on energy yield and economics of single‐axis‐tracked bifacial photovoltaics

Abstract Artificial ground reflectors improve bifacial energy yield by increasing both front and rear‐incident irradiance. Studies have demonstrated an increase in energy yield due to the addition of artificial reflectors; however, they have not addressed the effect of varying reflector dimensions and placement on system performance and the impact of these parameters on the reflectors' financial viability. We studied the effect of high albedo (70% reflective) artificial reflectors on single‐axis‐tracked bifacial photovoltaic systems through ray‐trace modeling and field measurements. In the field, we tested a range of reflector configurations by varying reflector size and placement and demonstrated that reflectors increased daily energy yield up to 6.2% relative to natural albedo for PERC modules. To confirm the accuracy of our model, we compared modeled and measured power and found a root mean square error (RMSE) of 5.4% on an hourly basis. We modeled a typical meteorological year in Golden, Colorado, to demonstrate the effects of artificial reflectors under a wide range of operating conditions. Seventy percent reflective material can increase total incident irradiance by 1.9%–8.6% and total energy yield by 0.9%–4.5% annually after clipping is considered with a DC–AC ratio of 1.2. Clipping has a significant effect on reflector impact and must be included when assessing reflector viability because it reduces reflector energy gain. We calculated a maximum viable cost for these improvements of up to $2.50–4.60/m 2 , including both material and installation, in Golden. We expanded our analysis to cover a latitude range of 32–48°N and demonstrated that higher‐latitude installations with lower energy yield and higher diffuse irradiance content can support higher reflector costs. In both modeling and field tests, and for all locations, the ideal placement of the reflectors was found to be directly underneath the module due to the optimized rear irradiance increase.

14 SOLAR ENERGY↗
DOE OSTI2019

Bioaccumulation of Cr, Ni, Cd and Pb in the Economically Important Freshwater Fish Schizothorax plagiostomus from Three Rivers of Malakand Division, Pakistan: Risk Assessment for Human Health

Contamination of freshwater ecosystems such as rivers with hazardous heavy metals is an environmental problem of public health concern. Accumulation of potentially toxic heavy metals in freshwater fish causes a potential health threat to their consumers including humans. The present research aimed to (1) investigate the accumulation of four potentially toxic heavy metals viz. Cr, Ni, Cd and Pb in muscle tissue of the commercially important freshwater fish Schizothorax plagiostomus at different sites of River Swat, River Panjkora and River Barandu in northern Pakistan (2) to compare gross metal accumulation in the fish samples by calculating metal pollution index (MPI) and (3) to assess potential risk to the health of the fish consumers. Samples were analyzed for the heavy metals by flame atomic absorption spectrophotometry (FAAS). Risk analysis showed that Ni risk was higher at River Panjkora and River Barandu, Pb risk was higher at River Swat and River Panjkora while Cd risk was quite low at all the three rivers.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2019

Minimally Invasive Treatment for Benign Prostatic Hyperplasia: Economic Evaluation from a Standardized Hospital Case Costing System

Purpose: Minimally invasive alternatives to transurethral resection of the prostate (TURP) such as prostate arterial embolization (PAE) and photoselective vaporization of the prostate (PVP) are being explored as adjuncts in the care of patients with benign prostatic hyperplasia. However, there are conflicting reports of the costs of these procedures. The purpose of this study was to compare the direct and indirect hospital costs of TURP, PAE and PVP. Materials and Methods: A chart review was performed in patients who underwent TURP, PVP and PAE from April 2015 to March 2017. All hospital costs were collected in accordance with the Ontario Case Costing Initiative, a standardized medical case costing system. Costs were characterized as direct or indirect and fixed or variable. Probabilistic sensitivity analysis was conducted to study cost uncertainty. Results: During the study period, a total of 209 men underwent TURP, 28 PVP and 21 PAE. Mean age (years) was as follows: TURP 71.43; PVP 73.66; PAE 70.77 (p = 0.366). Mean length of stay (days) was as follows: TURP 1.63; PVP 1.55; PAE 1 (p = 0.076). Total costs of the PAE group ($3829, SD $1582) were less than both PVP ($5719, SD $1515) and TURP groups ($5034, SD $1997, p < 0.001). There was no significant difference in direct costs between the groups. Monte Carlo simulation demonstrated that PAE was the least costly alternative majority of the time. Conclusions: The total hospital costs of PAE at our institution are significantly lower than those of PVP and TURP.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2015

Recycle of enriched Mo targets for economic production of 99 Mo/ 99m Tc medical isotope without use of enriched uranium

A new recycle process for recovery of enriched 98 Mo or 100 Mo used for production of 99 Mo/ 99m Tc medical isotope was developed. In this process, Mo is precipitated from spent NorthStar Mo/Tc generator solution containing ~200 g/L Mo as K 2 MoO 4 in 5 M KOH using acetic acid and then washed with nitric acid. High purification factors from potassium were achieved, and typical Mo recovery yields were ~95 %. In conclusion, the recycle process was performed with up to 260 g of Mo per batch and can be easily implemented for processing of up to 400 g of Mo.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗