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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 253 records · Page 14
All sourcesNASA NTRSDOE OSTI
DOE OSTI2023

Protein Extraction, Precipitation, and Recovery from Chlorella sorokiniana Using Mechanochemical Methods

Protein extraction, precipitation, and recovery methods were evaluated by this study using a green alga—Chlorella sorokiniana. A mechanochemical cell disruption process was applied to facilitate protein extraction from microalgal biomass. Optimization of the mechanochemical process resulted in milling conditions that achieved a protein extraction of 52.7 ± 6.45%. The consequent acid precipitation method was optimized to recover 98.7% of proteins from the microalgal slurry. The measured protein content of the protein isolate was 41.4% w/w. These results indicate that the precipitation method is successful at recovering the extracted proteins in the algal slurry; however, the removal of non-protein solids during centrifugation and pH adjustment is not complete. The energy balance analysis elucidated that the energy demand of the protein extraction and recovery operation, at 0.83 MJ/kg dry algal biomass, is much lower than previous studies using high-pressure homogenization and membrane filtration. This study concludes that mechanochemical protein extraction and recovery is an effective, low-energy processing method, which could be used by algal biorefineries to prepare algal proteins for value-added chemical production as well as to make algal carbohydrates and lipids in the residual biomass more accessible for biofuel production.

59 BASIC BIOLOGICAL SCIENCES↗
DOE OSTI2025

A Review of the Research and Development of Brayton Cycle Technology in Nuclear Power Applications with a Focus on Compressor Technology

This study reviews the integration of Brayton Cycle (BC) systems in nuclear power generation, emphasizing their potential to enhance thermal efficiency and operational flexibility over traditional Rankine Cycle (RC) systems. Key working fluids, such as helium (He), supercritical carbon dioxide (sCO 2 ), nitrogen (N 2 ), and air, are evaluated for their performance, efficiency, and compatibility with nuclear systems. He is recognized for its high thermal conductivity and inertness at elevated temperatures, while sCO 2 demonstrates advantages in compactness and efficiency in midrange temperatures. This article also highlights the importance of compressor designs in optimizing BC performance and reviews, available compressor technologies. Axial and centrifugal compressor designs enable efficient gas compression while managing the thermal and mechanical stresses associated with high-pressure operations in nuclear systems. Combined with variable geometry components and advanced materials, these technologies address the challenges posed by varying load conditions. Despite the promising features of BC systems, several challenges persist, including high leakage rates and material degradation under extreme conditions, which necessitate robust sealing technologies and thorough testing. The insights gained from operational experiences at facilities, such as the Oberhausen II plant and the High-Temperature He Test Facility (HHV), underscore the complexities involved in designing high-temperature gas turbines for nuclear applications. This review concludes that as the nuclear industry evolves, BC systems hold significant promise for contributing to a sustainable energy future, particularly in the context of small modular reactors (SMRs) and microreactors. Further exploration of combined cycle configurations that combine BCs with RCs may enhance overall efficiency and flexibility in power generation.

22 - GENERAL STUDIES OF NUCLEAR REACTORS↗
DOE OSTI2023

Volatile Fatty Acid Recovery from Arrested Anaerobic Digestion for the Production of Sustainable Aviation Fuel: A Review

The process of producing sustainable aviation fuel (SAF) from organic waste involves the use of volatile fatty acids (VFAs) as intermediates that are obtained via arrested anaerobic digestion (AAD) and VFA recovery. This recovery process often requires several steps, including dewatering, filtration, extraction, and purification. The recovery of VFAs is crucial for their upgrading and can pose a challenge in the production of SAF from organic waste due to high costs and compatibility issues. This review discusses various dewatering methods, including centrifuges, belt filter presses, and screw presses, and explores conditioning technologies that can improve dewatering performance. It also introduces filtration technologies, with a focus on dynamic filtration, which shows promise in addressing the issue of membrane fouling. Additionally, the review describes extraction technologies such as electrodialysis, adsorption, and liquid–liquid extraction (LLE). By providing insights into these different techniques, the review aims to contribute to the development of an integrated VFA recovery process with low carbon footprint.

09 BIOMASS FUELS↗
DOE OSTI2023

Simple Bioparticle Filtration Device Based on an Ultralow-Fouling Zwitterionic Polyurethane Membrane for Rapid Large-Volume Separation of Plasma and Viruses from Whole Blood

Plasma separation from whole blood is oftent required as an essential first step when performing blood tests with a viral assay. However, developing a point-of-care plasma extraction device with a large output and high virus recovery remains a significant obstacle to the success of on-site viral load tests. Here, we report a portable, easy-to-use, cost-efficient, membrane-filtration-based plasma separation device that enables rapid large-volume plasma extraction from whole blood, designed for point-of-care virus assays. The plasma separation is realized by a low-fouling zwitterionic polyurethane-modified cellulose acetate (PCBU-CA) membrane. The zwitterionic coating on the cellulose acetate membrane can decrease surface protein adsorption by 60% and increase plasma permeation by 46% compared with a pristine membrane. The PCBU-CA membrane, with its ultralow-fouling properties, enables rapid plasma separation. The device can yield a total of 1.33 mL plasma from 10 mL whole blood in 10 min. The extracted plasma is cell-free and exhibits a low hemoglobin level. In addition, our device demonstrated a 57.8% T7 phage recovery in the separated plasma. The results of real-time polymerase chain reaction analysis confirmed that the nucleic acid amplification curve of the plasma extracted by our device is comparable to that obtained by centrifugation. With its high plasma yield and good phage recovery, our plasma separation device provides an excellent replacement for traditional plasma separation protocols for point-of-care virus assays and a broad spectrum of clinical tests.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Laser-Plasma Spectroscopy of Hydroxyl with Applications

This article discusses laser-induced laboratory-air plasma measurements and analysis of hydroxyl (OH) ultraviolet spectra. The computations of the OH spectra utilize line strength data that were developed previously and that are now communicated for the first time. The line strengths have been utilized extensively in interpretation of recorded molecular emission spectra and have been well-tested in laser-induced fluorescence applications for the purpose of temperature inferences from recorded data. Moreover, new experiments with Q-switched laser pulses illustrate occurrence of molecular recombination spectra for time delays of the order of several dozen of microseconds after plasma initiation. The OH signals occur due to the natural humidity in laboratory air. Centrifugal stretching of the Franck-Condon factors and r-centroids are included in the process of determining the line strengths that are communicated as a Supplementary File. Laser spectroscopy applications of detailed OH computations include laser-induced plasma and combustion analyses, to name but two applications. This work also includes literature references that address various diagnosis applications.

47 OTHER INSTRUMENTATION↗
DOE OSTI2020

Enhanced Corneal Penetration of a Poorly Permeable Drug Using Bioadhesive Multiple Microemulsion Technology

Corneal penetration is a key rate limiting step in the bioavailability of topical ophthalmic formulations that incorporate poorly permeable drugs. Recent advances have greatly aided the ocular delivery of such drugs using colloidal drug delivery systems. Ribavirin, a poorly permeable BCS class-III drug, was incorporated in bioadhesive multiple W/O/W microemulsion (ME) to improve its corneal permeability. The drug-loaded ME was evaluated regarding its physical stability, droplet size, PDI, zeta potential, ultrastructure, viscosity, bioadhesion, in vitro release, transcorneal permeability, cytotoxicity, safety and ocular tolerance. Our ME possessed excellent physical stability, as it successfully passed several cycles of centrifugation and freeze–thaw tests. The formulation has a transparent appearance due to its tiny droplet size (10 nm). TEM confirmed ME droplet size and revealed its multilayered structure. In spite of the high aqueous solubility and the low permeability of ribavirin, this unique formulation was capable of sustaining its release for up to 24 h and improving its corneal permeability by 3-fold. The in vitro safety of our ME was proved by its high percentage cell viability, while its in vivo safety was confirmed by the absence of any sign of toxicity or irritation after either a single dose or 14 days of daily dosing. Our ME could serve as a vehicle for enhanced ocular delivery of drugs with different physicochemical properties, including those with low permeability.

Ibrahim, Mohamed Moustafa↗
DOE OSTI2022

Coprocessing Corn Germ Meal for Oil Recovery and Ethanol Production: A Process Model for Lipid-Producing Energy Crops

Efforts to engineer high-productivity crops to accumulate oils in their vegetative tissue present the possibility of expanding biodiesel production. However, processing the new crops for lipid recovery and ethanol production from cell wall saccharides is challenging and expensive. In a previous study using corn germ meal as a model substrate, we reported that liquid hot water (LHW) pretreatment enriched the lipid concentration by 2.2 to 4.2 fold. This study investigated combining oil recovery with ethanol production by extracting oil following LHW and simultaneous saccharification and co-fermentation (SSCF) of the biomass. Corn germ meal was again used to model the oil-bearing energy crops. Pretreated germ meal hydrolysate or solids (160 and 180 °C for 10 min) were fermented, and lipids were extracted from both the spent fermentation whole broth and fermentation solids, which were recovered by centrifugation and convective drying. Lipid contents in spent fermentation solids increased 3.7 to 5.7 fold compared to the beginning germ meal. The highest lipid yield achieved after fermentation was 36.0 mg lipid g−1 raw biomass; the maximum relative amount of triacylglycerol (TAG) was 50.9% of extracted oil. Although the fermentation step increased the lipid concentration of the recovered solids, it did not improve the lipid yields of pretreated biomass and detrimentally affected oil compositions by increasing the relative concentrations of free fatty acids.

09 BIOMASS FUELS↗
DOE OSTI2020

Rotationally Driven Ultraviolet Emission of Red Giant Stars

Main-sequence stars exhibit a clear rotation-activity relationship, in which rapidly rotating stars drive strong chromospheric/coronal ultraviolet and X-ray emission. While the vast majority of red giant stars are inactive, a few percent exhibit strong ultraviolet emission. Here we use a sample of 133 red giant stars observed by Sloan Digital Sky Survey APOGEE and Galaxy Evolution Explorer to demonstrate an empirical relationship between near-UV (NUV) excess and rotational velocity (v sin i). Beyond this simple relationship, we find that NUV excess also correlates with rotation period and with Rossby number in a manner that shares broadly similar trends to those found in M dwarfs, including activity saturation among rapid rotators. Our data also suggest that the most extremely rapidly rotating giants may exhibit so-called supersaturation, which could be caused by centrifugal stripping of these stars rotating at a high fraction of breakup speed. As an example application of our empirical rotation-activity relation, we demonstrate that the NUV emission observed from a recently reported system comprising a red giant with a black hole companion is fully consistent with arising from the rapidly rotating red giant in that system. Most fundamentally, our findings suggest a common origin of chromospheric activity in rotation and convection for cool stars from main sequence to red giant stages of evolution.

79 ASTRONOMY AND ASTROPHYSICS↗
DOE OSTI2023

Figuring Out Gas & Galaxies in Enzo (FOGGIE). VI. The Circumgalactic Medium of L * Galaxies Is Supported in an Emergent, Nonhydrostatic Equilibrium

The circumgalactic medium (CGM) is often assumed to exist in or near hydrostatic equilibrium, with the regulation of accretion and the effects of feedback treated as perturbations to a stable balance between gravity and thermal pressure. We investigate global hydrostatic equilibrium in the CGM using four highly resolved L* galaxies from the Figuring Out Gas & Galaxies in Enzo (FOGGIE) project. The FOGGIE simulations were specifically targeted at fine spatial and mass resolution in the CGM (Δx ≲ 1 kpc h –1 and M ≃ 200M ⊙ ). We develop a new analysis framework that calculates the forces provided by thermal pressure gradients, turbulent pressure gradients, ram pressure gradients of large-scale radial bulk flows, centrifugal rotation, and gravity acting on the gas in the CGM. Thermal and turbulent pressure gradients vary strongly on scales of ≲5 kpc throughout the CGM. Thermal pressure gradients provide the main supporting force only beyond ~0.25R 200 , or ~50 kpc at z = 0. Within ~0.25R 200 , turbulent pressure gradients and rotational support provide stronger forces than thermal pressure. More generally, we find that global equilibrium models are neither appropriate nor predictive for the small scales probed by absorption line observations of the CGM. Local conditions generally cannot be derived by assuming a global equilibrium, but an emergent global equilibrium balancing radially inward and outward forces is obtained when averaging over the nonequilibrium local conditions on large scales in space and time. Approximate hydrostatic equilibrium holds only at large distances from galaxies, even when averaging out small-scale variations.

79 ASTRONOMY AND ASTROPHYSICS↗
DOE OSTI2024

Limiting Rotation Rate of Neutron Stars from Crust Breaking and Gravitational Waves

Abstract Neutron stars are not observed to spin faster than about half their breakup rate. This limiting rotational frequency may be related to the strength of their crusts. As a star spins up from accretion, centrifugal forces stress the crust. We perform finite-element simulations of rotating neutron stars and find that the crust fails at rotation rates about half the breakup rate. Given uncertainties in microphysics, we have not determined the crust configuration after this failure. Instead, we argue that the crust may fail in an asymmetric way and could produce a configuration with a significant ellipticity (fractional difference in moments of inertia). If the ellipticity is large, a rotating star will radiate gravitational waves that may limit further spin-up. These stars may be promising sources for LIGO/VIRGO and next-generation gravitational-wave detectors.

Morales, J. A.↗
DOE OSTI2024

Development of CD46 targeted alpha theranostics in prostate cancer using 134 Ce/ 225 Ac-Macropa-PEG 4 -YS5

Rationale: 225 Ac, a long-lived α-emitter with a half-life of 9.92 days, has garnered significant attention as a therapeutic radionuclide when coupled with monoclonal antibodies and other targeting vectors. Nevertheless, its clinical utility has been hampered by potential off-target toxicity, a lack of optimized chelators for 225 Ac, and limitations in radiolabeling methods. In a prior study evaluating the effectiveness of CD46-targeted radioimmunotherapy, we found great therapeutic efficacy but also significant toxicity at higher doses. To address these challenges, we have developed a radioimmunoconjugate called 225 Ac-Macropa-PEG 4 -YS5, incorporating a stable PEGylated linker to maximize tumoral uptake and increase tumor-to-background ratios. Our research demonstrates that this conjugate exhibits greater anti-tumor efficacy while minimizing toxicity in prostate cancer 22Rv1 tumors. Methods: We synthesized Macropa.NCS and Macropa-PEG 4/8 -TFP esters and prepared Macropa-PEG 0/4/8 -YS5 (with nearly ~1:1 ratio of macropa chelator to antibody YS5) as well as DOTA-YS5 conjugates. These conjugates were then radiolabeled with 225 Ac in a 2 M NH 4 OAc solution at 30 °C, followed by purification using YM30K centrifugal purification. Subsequently, we conducted biodistribution studies and evaluated antitumor activity in nude mice (nu/nu) bearing prostate 22Rv1 xenografts in both single-dose and fractionated dosing studies. Micro-PET imaging studies were performed with 134 Ce-Macropa-PEG 0/4/8 -YS5 in 22Rv1 xenografts for 7 days. Toxicity studies were also performed in healthy athymic nude mice. Results: As expected, we achieved a >95% radiochemical yield when labeling Macropa-PEG 0/4/8 -YS5 with 225 Ac, regardless of the chelator ratios (ranging from 1 to 7.76 per YS5 antibody). The isolated yield exceeded 60% after purification. Such high conversions were not observed with the DOTA-YS5 conjugate, even at a higher ratio of 8.5 chelators per antibody (RCY of 83%, an isolated yield of 40%). Biodistribution analysis at 7 days post-injection revealed higher tumor uptake for the 225 Ac-Macropa-PEG 4 -YS5 (82.82 ± 38.27 %ID/g) compared to other conjugates, namely 225 Ac-Macropa-PEG 0/8 -YS5 (38.2 ± 14.4/36.39 ± 12.4 %ID/g) and 225 Ac-DOTA-YS5 (29.35 ± 7.76 %ID/g). The PET Imaging of 134 Ce-Macropa-PEG 0/4/8 -YS5 conjugates resulted in a high tumor uptake, and tumor to background ratios. In terms of antitumor activity, 225 Ac-Macropa-PEG 4 -YS5 exhibited a substantial response, leading to prolonged survival compared to 225 Ac-DOTA-YS5, particularly when administered at 4.625 kBq doses, in single or fractionated dose regimens. Chronic toxicity studies observed mild to moderate renal toxicity at 4.625 and 9.25 kBq doses. Conclusions: Our study highlights the promise of 225 Ac-Macropa-PEG 4 -YS5 for targeted alpha particle therapy. The 225 Ac-Macropa-PEG 4 -YS5 conjugate demonstrates improved biodistribution, reduced off-target binding, and enhanced therapeutic efficacy, particularly at lower doses, compared to 225 Ac-DOTA-YS5. Incorporating theranostic 134 Ce PET imaging further enhances the versatility of macropa-PEG conjugates, offering a more effective and safer approach to cancer treatment. Overall, this methodology has a high potential for broader clinical applications.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2020

In-Field Alpha Spectrometry to Assess Uranium Enrichment In Uranium Hexafluoride

A new In-Field Alpha Spectrometry (IFAS) system is being developed to allow quick turnaround measurements of uranium enrichment in uranium hexafluoride (UF6) samples. Samples are collected using specially-designed Single-Use Destructive Assay (SUDA) wafers which have an absorptive film of zeolite deposited onto a quartz or metal substrate. The SUDA samples, along with a special holder, are designed to be attached directly to a sampling tap at a gas centrifuge enrichment plant or a uranium conversion facility, allowing gaseous UF6 to come into direct contact with the zeolite. The zeolite absorbs this material and converts it into stable, safe UO2F2 within a few minutes. Once the sample has been collected it is transferred to the IFAS system where a solid-state, silicon alpha spectrometer is used to quantitatively measure the alpha emissions from 234U, 235U, and 238U in the sample. The IFAS system is a small, light-weight device that can be quickly turned on and put into use. The SUDA samples and IFAS hardware are designed so that thin-film spectra are produced, allowing a complete measurement with a final 235U:Utotal determination having a precision <±2% to be made in less than eight hours. This short time frame will allow an inspector to get results on-site within one working shift; further innovations may reduce this to even shorter times.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗
DOE OSTI2020

Detection of active and latent infections with microfluidic devices and systems thereof

The present invention relates to methods of detecting one or more targets of interest in a sample. In one instance, the target can be correlated to an active infection (e.g., by a virus and/or a bacterium). Methods can include treating the sample with a dissociation agent, thereby releasing the target of interest for more accurate detection (e.g., by use of a sedimentation-based centrifugal microfluidic devices). Also described herein are microfluidic devices and systems for use with a dissociation agent.

59 BASIC BIOLOGICAL SCIENCES↗
DOE OSTI2021

Attacking the IEC-61131 Logic Engine in Programmable Logic Controllers in Industrial Control Systems

In industrial control systems (ICS), programmable logic controllers (PLCs) directly monitor and control a physical process such as nuclear power plants, gas pipelines, and water treatment. They are equipped with a control logic written in IEC-61131 languages (e.g., ladder logic and structured text) that defines how a PLC should control a physical process. A PLC's control logic is a usual target of a cyberattack to sabotage a physical process. For instance, Stuxnet targets a control logic of a Siemens S7-300 PLC to damage a nuclear facility's centrifuges. The existing attacks in the literature generally focus only on injecting malicious control logic into a PLC. This paper presents a new dimension of control logic attacks that target the control logic engine (responsible for running a control logic) of a PLC. It demonstrates that a cyberattack can disable the control logic engine successfully by exploiting inherent PLC features such as program mode and starting/stopping engine. We develop two novel case studies on control logic engine attacks by employing the MITRE ATT\&CK knowledge base on the real-world PLCs used in industry settings, i.e., 1) Schweitzer Engineering Laboratory (SEL)'s Real-Time Automation Controller (SEL-3505 RTAC) equipped with security features such as encrypted traffic and device-level access control, and 2) traditional PLCs, i.e., Schneider Electric's Modicon M221, Allen-Bradley's MicroLogix 1400 and 1100 that do not have security features. The case studies present the internals of the logic engine attacks and facilitate the ICS research community and industry to understand the attack vectors on the control logic engine. We evaluate the effectiveness of the control engine attacks on a power substation, a 4-floor elevator, and a conveyor belt to demonstrate their real-world impact of halting a physical process.

Ali qasim, Syed↗
DOE OSTI2021

Detection of metabolites for controlled substances

The various technologies presented herein relate to identifying whether an individual has taken, and/or is under the influence of, a restricted drug. A density separation technique is utilized, wherein a sample (e.g., blood, saliva, urine, etc.) which may include an analyte is exposed to a first plurality of beads having an analyte attached thereto, a second plurality of beads having a metabolite-specific antibody attached thereto, and a plurality of fluorophore-labelled analyte-specific antibodies. After incubation, any analyte in the sample (e.g., delta-9-THC) is bound to the fluorophore-labelled analyte-specific antibodies, any free fluorophore-labelled analyte-specific antibodies are attached to the analyte of the first beads, and any metabolite in the sample is bound to the second antibody. By applying centrifugal separation, the first beads move to a region which undergoes irradiation. If no fluorescence occurs, the sample includes the analyte; if fluorescence occurs, the sample does not include the analyte.

Koh, Chung-Yan↗