Engineering Papers⌕ Search

SEARCH · Engineering Papers

Results for “Extraction”

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.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 937 records · Page 52
All sourcesNASA NTRSDOE OSTI
DOE OSTI2012

Ion energy distribution functions of low energy beams formed by wire extraction electrodes

The two-electrode extractor system made of 0.1 mm diameter tungsten wires separated by 0.7 mm has formed an argon ion beam with 50 V extraction potential. Energy spreads of the extracted beams were typically less than 2 eV when the beam current density was low. The beam intensity rapidly decreased as the distance between the extractor and the beam detector increased, indicating space charge limited transport of the beam. Problems associated with the emittance measurements are also discussed.

43 PARTICLE ACCELERATORS↗
DOE OSTI2014

Next Generation Solvent (NGS): Development for Caustic-Side Solvent Extraction of Cesium

This report summarizes the FY 2010 and 2011 accomplishments at Oak Ridge National Laboratory (ORNL) in developing the Next Generation Caustic-Side Solvent Extraction (NG-CSSX) process, referred to commonly as the Next Generation Solvent (NGS), under funding from the U.S. Department of Energy, Office of Environmental Management (DOE-EM), Office of Technology Innovation and Development. The primary product of this effort is a process solvent and preliminary flowsheet capable of meeting a target decontamination factor (DF) of 40,000 for worst-case Savannah River Site (SRS) waste with a concentration factor of 15 or higher in the 18-stage equipment configuration of the SRS Modular Caustic-Side Solvent Extraction Unit (MCU). In addition, the NG-CSSX process may be readily adapted for use in the SRS Salt Waste Processing Facility (SWPF) or in supplemental tank-waste treatment at Hanford upon appropriate solvent or flowsheet modifications. Efforts in FY 2010 focused on developing a solvent composition and process flowsheet for MCU implementation. In FY 2011 accomplishments at ORNL involved a wide array of chemical-development activities and testing up through single-stage hydraulic and mass-transfer tests in 5-cm centrifugal contactors. Under subcontract from ORNL, Argonne National Laboratory (ANL) designed a preliminary flowsheet using ORNL cesium distribution data, and Tennessee Technological University confirmed a chemical model for cesium distribution ratios (DCs) as a function of feed composition. Interlaboratory efforts were coordinated with complementary engineering tests carried out (and reported separately) by personnel at Savannah River National Laboratory (SRNL) and Savannah River Remediation (SRR) with helpful advice by Parsons Engineering and General Atomics on aspects of possible SWPF implementation.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2011

4D Emittance Measurements Using Multiple Wire and Waist Scan Methods in the ATF Extraction Line

Emittance measurements performed in the diagnostic section of the Accelerator Test Facility (ATF) extraction line since 1998 led to vertical emittances three times larger than the expected ones, with a strong dependence on intensity. An experimental program is pursued to investigate potential sources of emittance growth and find possible remedies. This requires efficient and reliable emittance measurement techniques. In the past, several phase-space reconstruction methods developed at SLAC and KEK have been used to estimate the vertical emittance, based on multiple location beam size measurements and dedicated quadrupole scans. These methods have been shown to be very sensitive to measurement errors and other fluctuations in the beam conditions. In this context new emittance measurements have been performed revisiting these methods and newly developed ones with a systematic approach to compare and characterise their performance in the ATF extraction line.

43 PARTICLE ACCELERATORS↗
DOE OSTI2013

Life Extension Program for the Modular Caustic Side Solvent Extraction Unit at Savannah River Site - 13179

Caustic Side Solvent Extraction (CSSX) is currently used at the U.S. Department of Energy (DOE) Savannah River Site (SRS) for removal of cesium from the high-level salt-wastes stored in underground tanks. Currently, the Actinide Removal Process (ARP) and the CSSX process are deployed in the (ARP)/Modular CSSX Unit (MCU), to process salt waste for permanent disposition. The CSSX technology utilizes a multi-component organic solvent and annular centrifugal contactors to extract cesium from alkaline salt waste. The original plant was permitted for a three year design life; however, given the successful operation of the plant, a life extension program was completed to continue operations. The program included detailed engineering analyses of the life-expectancy of passive and active components, resulting in component replacement and/or maintenance and monitoring program improvements. The program also included a review of the operations and resulted in a series of operational improvements. Since the improvements have been made, an accelerated processing rate has been demonstrated. In addition, plans for instituting a next-generation solvent are in place and will enhance the decontamination factors. (author)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2017

Hydrological Drought in the Anthropocene: Impacts of Local Water Extraction and Reservoir Regulation in the U.S.

Hydrological drought is a substantial negative deviation from normal hydrologic conditions and is influenced by climate and human activities such as water management. By perturbing the streamflow regime, climate change and water management may significantly alter drought characteristics in the future. Here we utilize a high-resolution integrated modeling framework that represents water management in terms of both local surface water extraction and reservoir regulation, and use the Standardized Streamflow Index (SSI) to quantify hydrological drought. We explore the impacts of water management on hydrological drought over the contiguous US in a warming climate with and without emissions mitigation. Despite the uncertainty of climate change impacts, local surface water extraction consistently intensifies drought that dominates at the regional to national scale. However, reservoir regulation alleviates drought by enhancing summer flow downstream of reservoirs. The relative dominance of drought intensification or relief is largely determined by the water demand, with drought intensification dominating in regions with intense water demand such as the Great Plains and California, while drought relief dominates in regions with low water demand. Here, at the national level, water management increases the spatial extent of extreme drought despite some alleviations of moderate to severe drought. In an emissions mitigation scenario with increased irrigation demand for bioenergy production, water management intensifies drought more than the business-as-usual scenario at the national level, so the impacts of emissions mitigation must be evaluated by considering its benefit in reducing warming and evapotranspiration against its effects on increasing water demand and intensifying drought.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2023

Improved Light Extraction in Organic Light‐Emitting Diodes via Semiconductor Dilution

Increasing the internal light extraction efficiency of organic light‐emitting diodes (OLEDs) is key to improving their performance for solid‐state lighting applications; however, it is challenging to do this in a way that is compatible with high volume manufacturing. Here, it is shown that the outcoupling efficiency of OLEDs can be improved by diluting their hole transport layer (HTL) with the low refractive index material trifluoropropyl oligomeric silsesquioxane (F‐POSS). Specifically, co‐evaporating 40 vol.% F‐POSS in the HTL of single and multi‐stack phosphorescent OLEDs decreases its refractive index by Δ n ≈ 0.2, which in turn yields a ≈12% increase in their outcoupling efficiency with no impact on electrical performance or operational lifetime. This result is significant because F‐POSS is a small molecule that sublimes cleanly, does not aggregate, and is compatible with state‐of‐the‐art HTL materials, making it a realistic path to increase light extraction in commercial OLEDs manufactured on existing production lines.

36 MATERIALS SCIENCE↗
DOE OSTI2016

A Polymer Hole Extraction Layer for Inverted Perovskite Solar Cells from Aqueous Solutions

Poly(Phenylene vinylene) anionic polyelectrolyte (PVBT-SO 3 ) was found to be an efficient hole extraction layer for inverted perovskite solar cells. It can be cast from an aqueous solution and does not require thermal annealing for improved device performance. The devices show maximum solar cell efficiency of 15.9% and exhibit improved stability under ambient conditions and enhanced charge extraction.

14 SOLAR ENERGY↗
DOE OSTI2017

Highly Efficient and Uniform 1 cm 2 Perovskite Solar Cells with an Electrochemically Deposited NiO x Hole-Extraction Layer

Here, given that the highest certified conversion efficiency of the organic-inorganic perovskite solar cell (PSC) already exceeds 22%, which is even higher than that of the polycrystalline silicon solar cell, the significance of new scalable processes that can be utilized for preparing large-area devices and their commercialization is rapidly increasing. From this perspective, the electrodeposition method is one of the most suitable processes for preparing large-area devices because it is an already commercialized process with proven controllability and scalability. Here, a highly uniform NiO x layer prepared by electrochemical deposition is reported as an efficient hole-extraction layer of a p-i-n-type planar PSC with a large active area of >1 cm 2 . It is demonstrated that the increased surface roughness of the NiO x layer, achieved by controlling the deposition current density, facilitates the hole extraction at the interface between perovskite and NiO x , and thus increases the fill factor and the conversion efficiency. The electrochemically deposited NiO x layer also exhibits extremely uniform thickness and morphology, leading to highly efficient and uniform large-area PSCs. As a result, the p-i-n-type planar PSC with an area of 1.084 cm 2 exhibits a stable conversion efficiency of 17.0% (19.2% for 0.1 cm 2 ) without showing hysteresis effects.

14 SOLAR ENERGY↗
DOE OSTI2026

Continuous Counter‐Current Microfluidic Liquid–Liquid Extraction Achieved Using a Pair of Wettable Screen Meshes

Continuous counter‐current microfluidic liquid–liquid extraction performs separations by flowing immiscible liquids in opposing directions within a single flow channel. In principle, this flow arrangement enables a large number of theoretical separation units in a small footprint, without using interstage valving, pumping, and phase separation. Despite its potential for excellent separation performance, this microfluidic scheme rarely appears in literature due to the requirement for capillary forces to be greater than hydrodynamic forces for stable flow. We present a novel microfluidic device and flow approaches that overcome this force‐balance challenge, enabling stable, long‐duration continuous counter‐current flow. Additionally, we cover a suite of methodologies for quantifying the performance of the microfluidic device, revealing the number of theoretical equilibrium stages achieved. The enabling technologies include a woven mesh screen‐based microfluidic device architecture that is easily fabricated outside of a clean room, surface functionalization strategies to promote conjugate (organic/aqueous) wettability, flow approaches to eliminate bubbles and carryover, and computer‐aided flow automation with optical measurement of extraction performance. The reported experiments lasted for over 36 h, terminated only at experiment conclusion, where the device still exhibited good performance. Automated Raman spectroscopy was used for solute quantitation of the ternary system tert‐butanol in a toluene/water matrix, a ternary system that was specifically chosen to analyze the device's performance with a small solute partition ratio and to enable in‐line Raman measurements of solute concentrations in both phases. The microfluidic device possessed a 55 mm contact length and a 38.5 µL internal volume. During counter‐current flow, we observed approximately 37 equilibrium stages (37 ± 13) based on a best‐fit of the solute fraction remaining in the aqueous phase using a Kremser Group Method analysis.

36 MATERIALS SCIENCE↗
DOE OSTI2017

Quantum chemistry benchmarking of binding and selectivity for lanthanide extractants

Computer-aided screening methods facilitate the discovery of new extractants for heavy and rare-earth metal separations. In this work, we have benchmarked the accuracy of different quantum chemistry methods for calculating extractant binding energies and selectivities. Specifically, we compare calculated data from different exchange correlation functionals (B3LYP-D3, ωB97X-D3, and M06-L) and different basis sets (including large-core effective core potentials and all-electron basis sets). We report aqueous-phase binding energy and selectivity trends for 1:1 and 3:1 extractant/lanthanide models for the complexes. We find that binding selectivities are not particularly sensitive to model chemistry, but binding energies are sensitive. Furthermore, calculated trends in selectivity using 3:1 extractant/lanthanide models are in better agreement with available experimental trends than trends using 1:1 extractant/lanthanide models. Lastly, we find that the B3LYP-D3/6-31 + G* model chemistry with the Stuttgart large-core relativistic effective core potentials on the lanthanide sufficiently reproduces results from larger basis set calculations and is confirmed as suitable for relatively fast and efficient screening of lanthanide binding energies and selectivities.

36 MATERIALS SCIENCE↗
DOE OSTI2019

Solid Phase Extraction of Cadmium and Lead from Water by Amberlyst 15 and Determination by Flame Atomic Absorption Spectrometry

Preconcentration of Cd(II) and Pb(II) was carried out by using column solid phase extraction method. Amberlyst 15 was used as solid phase for these analytes. The optimum extraction conditions such as pH (4), type and volume of eluent (5 mL of 2 mol L{sup −1} HNO{sub 3}) sample flow rate (1 mL min{sup −1}) and sample volume (100 mL for Cd(II) and 750 mL for Pb(II)) were determined. The recoveries were found for Cd(II) and Pb(II) as 104% ± 1% and 102 % ± 2%, respectively. The limit of detections were found as 0.23 µg L{sup −1} for Cd(II) and 0.13 µg L{sup −1} for Pb(II). The effects of foreign ions were also studied. The method was validated by analyzing standard reference material and spiked water samples. Percent relative error and relative standard deviation were below 3% and 4%, respectively.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2011

Minimally Invasive Catheter Procedures to Assist Complicated Pacemaker Lead Extraction and Implantation in the Operating Room

We report on percutaneous catheter procedures in the operating room (OR) to assist complicated manual extraction or insertion of pacemaker (PM) and implantable cardioverter defibrillator leads. We retrospectively reviewed complicated PM revisions and implantations performed between 2004 and 2009 that required percutaneous catheter procedures performed in the OR. The type of interventional procedure, catheter and retrieval system used, venous access, success rates, and procedural complications were analyzed. In 41 (12 female and 29 male [mean age 62 {+-} 17 years]) of 3021 (1.4%) patients, standard manual retrieval of old leads or insertion of new leads was not achievable and thus required percutaneous catheter intervention for retrieval of misplaced leads and/or recanalisation of occluded central veins. Thirteen of 18 (72.2%) catheter-guided retrieval procedures for misplaced (right atrium [RA] or ventricle [RV; n = 3], superior vena cava [n = 2], brachiocephalic vein [n = 5], and subclavian vein [n = 3]) lead fragments in 16 patients were successful. Percutaneous catheter retrieval failed in five patients because there were extremely fixed or adhered lead fragments. Percutaneous transluminal angiography (PTA) of central veins for occlusion or high-grade stenosis was performed in 25 patients. In 22 of 25 patients (88%), recanalization of central veins was successful, thus enabling subsequent lead replacement. Major periprocedural complications were not observed. In the case of complicated manual PM lead implantation or revision, percutaneous catheter-guided extraction of misplaced lead fragments or recanalisation of central veins can be performed safely in the OR, thus enabling subsequent implantation or revision of PM systems in the majority of patients.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2011

Percutaneous Treatment of Biliary Cast Syndrome After Orthotopic Liver Transplantation: Comparison of Mechanical Versus Hydraulic Rheolytic Cast Extraction

Purpose: Biliary cast syndrome (BCS) is the presence of casts within the intrahepatic or extrahepatic biliary system after orthotopic liver transplantation. Our work compares two percutaneous methods for BCS treatment: the mechanical cast-extraction technique (MCE) versus the hydraulic cast-extraction (HCE) technique using a rheolytic system. Materials and Methods: A total of 24 patients were included in the study. Six patients were referred for HCE, and 18 patients were treated with MCE. A statistically significant larger number of sessions was required in the MCE group (21.0, range 11 to 72 sessions) (p = 0.033). Results: Median therapy duration was shorter in the HCE group at 2.4 months (range 2 to 5) compared with 6.7 months (range 3 to 39) in the MCE group (p < 0.001). Both patient acceptance was better and costs for total therapy were 40% less in the HCE group. No significant differences where found concerning clinical and biochemical improvement or graft and patient survival. Conclusion: The use of the hydraulic rheolytic system decreased total therapy time, thereby decreasing the induced inflammation time of the biliary tree. A significant benefit of HCE has been observed in our patients when we compare our results with those of MCE.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2018

Extraction and Characterization of Nanocrystalline Cellulose from Cassava Bagasse

The objective of this study was to produce highly crystalline nanocellulose from cassava bagasse, which is a by-product from the cassava starch industry that contains 15 to 50 wt% cellulose fibers. For this purpose, the lignocellulosic fiber that was isolated from cassava bagasse was bleached with sodium chlorite and hydrolyzed with sulfuric acid. The obtained suspension was spray-dried and the resulting microparticles were characterized by X-ray diffractometry to determine the crystallinity index. Microcrystalline cellulose was subjected to the same processing conditions and considered as a reference. The crystallinity index of the nanocellulose extracted from the cassava bagasse was higher than the crystallinity index of the nanocellulose extracted from the microcrystalline cellulose; 84.1 and 78.7%, respectively. No other studies have reported cellulose nanocrystals from cassava bagasse with a high crystallinity index. The nanocrystalline cellulose produced in this study is very promising for use in innovative industrial applications.

36 MATERIALS SCIENCE↗
DOE OSTI2018

Efficient Acetylation of Xylans by Exploiting the Potassium Acetate Formed During the Alkaline Extraction

Isolation of hemicelluloses through alkaline extraction results in formation of salts, which usually necessitates additional salt removal steps. In this study, acetylation of xylans was studied without the removal of potassium acetate (KAc), a commonly produced salt during the alkaline extraction, to find a facile method to alter the hydrophilic characteristics of hemicelluloses. The acetylation reaction was carried out solely with acetic anhydride without any catalysts or solvents added. The weight gain and ATR–FTIR analyses verified the acetylation of xylans in the presence of KAc. A significant decrease in water solubility and moisture uptake was observed upon acetylation in the presence of KAc which is also accompanied by an increase in thermal stability, disclosing an easy, efficient and environmentally friendly method to obtain hydrophobically modified xylans without the use of toxic catalysts and costly salt purification steps.

36 MATERIALS SCIENCE↗
DOE OSTI2023

A Thermodynamic Model for Nd(III)–Sulfate Interaction at High Ionic Strengths and Elevated Temperatures: Applications to Rare Earth Element Extraction

Neodymium (Nd), a rare earth element (REE), is critical to numerous industries. Neodymium can be extracted from ore concentrates, waste materials, or recycled materials such as recycled Nd-Fe-B permanent magnets. In a standard process, concentrated sulfuric acid (H 2 SO 4 ) is used as an extraction/leaching agent. Therefore, knowledge of Nd(III)–sulfate interaction at high ionic strengths is important for optimization of the extraction process. In addition, sulfate is also a major species in natural surface waters and present in nuclear waste streams. Nd(III) has been used a chemical analog to trivalent actinides in nuclear waste research and development. Consequently, knowledge of Nd(III)-sulfate interactions is also impactful to the field of nuclear waste management. Here, in this study, we have developed a thermodynamic model that can describe the interaction of Nd(III) with sulfate to ionic strengths up to ~ 16.5 mol·kg –1 and to temperatures up to 100 °C. The model adopts the Pitzer formulation to describe activity coefficients of aqueous species. This model can be used to design and optimize a chemical process for REE recovery from ore concentrates, recycled materials, and acid mine drainage (AMD) and to understand the mobility of REEs and actinides in the environment.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2017

Extraction of 211 At from nitric acid solutions into various organic solvents for use as an α-source for radiation chemistry studies

The partitioning of 211 At from an irradiated bismuth target using solvent extraction into several organic solvents is presented. Although astatine speciation is difficult to measure given its invariably low chemical concentration its extraction here is consistent with the existence of a cationic species in nitric acid that is not reduced upon contact with the organic phase. This is consistent with previous work that postulated the most probable species in acidic solution as AtO + . The technique presented here has a simple experimental set up and provides high specific activity astatine solutions compatible for use in α-radiolysis studies.

07 ISOTOPE AND RADIATION SOURCES↗
DOE OSTI2018

Studies of the homologs and pseudo-homologs of flerovium with crown ether based extraction chromatography resins

A crown-ether based extraction chromatography resin, Eichrom Pb, has been characterized for separations of the flerovium (Fl) pseudo-homolog Hg. Previous results on the batch uptake of Pb(II) and Sn(IV) are compared with newly investigated Hg(II) in HCl matrices. It was determined that all three elements can be strongly retained by the resin at different HCl concentrations. To assess the feasibility for performing an experiment on the chemical properties of Fl using this resin the extraction kinetics were studied. In conclusion, a separation method for the isolation of the homologs Pb(II) and Sn(IV) and pseudo-homolog Hg(II) has been established using 2 mL pre-packed Pb resin columns under vacuum flow.

38 RADIATION CHEMISTRY, RADIOCHEMISTRY, AND NUCLEA↗