Engineering Papers⌕ Search

SEARCH · Engineering Papers

Results for “Aqueous”

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 1,009 records · Page 56
All sourcesNASA NTRSDOE OSTI
DOE OSTI2024

Valorization of lignin from aqueous-based lignocellulosic biorefineries

An additional 100 million tons/year of lignin coproduct will result when lignocellulosic biomass is processed in biorefineries to fiber, sugars, biofuels, and bioproducts. This will double the amount of lignin already generated from pulping and paper production. Unlike pulping that results in lignosulphonate (88% of total) or Kraft lignin (9%), aqueous-based biorefining leaves behind non-sulfonated lignin and aromatic molecules. Furthermore, this new type of lignin provides opportunities for large volume agricultural uses such as controlled-release carriers and soil amendments as well as feedstocks for new chemistries that lead to molecular building blocks for the chemical industry and to precursors for sustainable aviation biofuels.

03 NATURAL GAS↗
DOE OSTI2010

AQUEOUS HOMOGENEOUS REACTORTECHNICAL PANEL REPORT

Considerable interest has been expressed for developing a stable U.S. production capacity for medical isotopes and particularly for molybdenum- 99 (99Mo). This is motivated by recent re-ductions in production and supply worldwide. Consistent with U.S. nonproliferation objectives, any new production capability should not use highly enriched uranium fuel or targets. Conse-quently, Aqueous Homogeneous Reactors (AHRs) are under consideration for potential 99Mo production using low-enriched uranium. Although the Nuclear Regulatory Commission (NRC) has guidance to facilitate the licensing process for non-power reactors, that guidance is focused on reactors with fixed, solid fuel and hence, not applicable to an AHR. A panel was convened to study the technical issues associated with normal operation and potential transients and accidents of an AHR that might be designed for isotope production. The panel has produced the requisite AHR licensing guidance for three chapters that exist now for non-power reactor licensing: Reac-tor Description, Reactor Coolant Systems, and Accident Analysis. The guidance is in two parts for each chapter: 1) standard format and content a licensee would use and 2) the standard review plan the NRC staff would use. This guidance takes into account the unique features of an AHR such as the fuel being in solution; the fission product barriers being the vessel and attached systems; the production and release of radiolytic and fission product gases and their impact on operations and their control by a gas management system; and the movement of fuel into and out of the reactor vessel.

07 ISOTOPE AND RADIATION SOURCES↗
DOE OSTI2016

Aqueous Nitrate Recovery Line at Los Alamos National Laboratory

This powerpoint is part of the ADPSM Plutonium Engineering Lecture Series, which is an opportunity for new hires at LANL to get an overview of work done at TA55. It goes into detail about the aqueous nitrate recovery line at Los Alamos National Laboratory.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2025

Using a recirculating anaerobic dynamic membrane bioreactor to treat hydrothermal liquefaction aqueous by-product

Hydrothermal liquefaction (HTL) has the potential to improve resource recovery at water resource recovery facilities (WRRF), but the production of a high-strength aqueous by-product (HTL-aq) is hampering HTL implementation. The formation of biofilms in anaerobic digestion have been shown to be useful when degrading recalcitrant compounds present in HTL-aq due to the promotion of direct interspecies electron transfer (DIET) and increase in the microbial activity of syntrophic and methanogenic populations. The Recirculating Anaerobic Dynamic Membrane Bioreactor (RAnDMBr) was able to degrade 65% of the chemical oxygen demand (COD) at 1.5 ± 0.2 g COD LR −1 day −1 and 5.6 ± 2.3 days producing 0.19 ± 0.02 LCH4 gCOD fed −1 . However, adding a solution rich in nutrients on a daily basis was necessary. The system presented microbial populations able to degrade aromatic compounds (i.e., Anaerolinaceae) to perform DIET and syntrophy (i.e., Syntrophus) and methanogens (i.e., Methanobacterium and Methanosarcina) with the biofilm having a higher relative abundance of methanogens than the suspended biomass. Increasing the organic loading rate to 2 g COD LR −1 day −1 caused inhibition in the system by accumulation of volatile fatty acids, probably due to an increase in phenol, N-heterocyclic and aromatic compounds. Overall, this research shows that the RAnDMBr can be used to treat HTL-aq in WRRF without inhibition at OLRs of 1.5 ± 0.2 g COD LR −1 day −1 or lower, making HTL-aq treatment more feasible. Future research should focus co-digestion of HTL-aq with a co-substrate rich in nutrients and on fouling mitigation strategies that will allow to increase the recirculation ratio to promote advective substrate transport through the biofilm.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2021

Employing the Dynamics of the Electrochemical Interface in Aqueous Zinc-Ion Battery Cathodes

Intrinsically stable materials are desirable for constructing energy storage devices, which aim to demonstrate durability under the harsh electrochemical conditions that are detrimental to their lifespan. However, in this study it is demonstrated that the intrinsic instability of an electrochemical interface can be converted from an obstacle into an advantage. In aqueous zinc-ion batteries, manganese oxide (MnO 2 ) exhibits considerable dissolution even in electrolyte containing Mn 2+ salt. Balancing with redeposition alleviates the harmful impact of dissolution on performance and alters the trajectory of the active phase. Inclusion of Mn 2+ salt in the electrolyte induces MnO 2 deposition on all conductive surfaces, requiring that distracting side reactions be eliminated to isolate the dynamics of the active phase. Under conditions favoring dissolution, capacity decreases dramatically and a highly crystalline tetragonal ZnMn 2 O 4 phase forms, while redeposition helps maintain capacity and promotes a disordered cubic Zn-rich phase. Ultimately, this work aims to illuminate a path forward to unlock the potential of batteries made with materials that are fundamentally unstable in their operating environment.

25 ENERGY STORAGE↗
DOE OSTI2017

Multichannel Interdiffusion Driven FASnI 3 Film Formation Using Aqueous Hybrid Salt/Polymer Solutions toward Flexible Lead-Free Perovskite Solar Cells

Tin (Sn)-based perovskites are increasingly attractive because they offer lead-free alternatives in perovskite solar cells. Yet, depositing high-quality Sn-based perovskite films is still a challenge, particularly for low-temperature planar heterojunction (PHJ) devices. In this work, a “multichannel interdiffusion” protocol is demonstrated by annealing stacked layers of aqueous solution deposited formamidinium iodide (FAI)/polymer layer followed with an evaporated SnI 2 layer to create uniform FASnI 3 films. In this protocol, tiny FAI crystals, significantly inhibited by the introduced polymer, can offer multiple interdiffusion pathways for complete reaction with SnI 2 . What is more, water, rather than traditional aprotic organic solvents, is used to dissolve the precursors. The best-performing FASnI 3 PHJ solar cell assembled by this protocol exhibits a power conversion efficiency (PCE) of 3.98%. In addition, a flexible FASnI 3 -based flexible solar cell assembled on a polyethylene naphthalate–indium tin oxide flexible substrate with a PCE of 3.12% is demonstrated. This novel interdiffusion process can aid to further boost the performance of lead-free Sn-based perovskites.

14 SOLAR ENERGY↗
DOE OSTI2021

Achieving Stable Molybdenum Oxide Cathodes for Aqueous Zinc-Ion Batteries in Water-in-Salt Electrolyte

A layered MoO 3 material with large interlayer spacing represents a promising cathode for aqueous rechargeable Zn-ion batteries (ARZIBs), but the implementation of this material is limited due to the intrinsically low conductivity and poor structural stability. A 30 m ZnCl 2 water-in-salt electrolyte (WISE) was introduced to a MoO 3 nanobelt cathode for the first time, significantly increasing the stability of MoO 3 cathodes compared to those in 3 M ZnSO 4 and 3 M ZnCl2 electrolyte. The Zn/MoO 3 cell in WISE unambiguously demonstrated significantly improved rate performance delivering 349, 253, and 222 mAh/g at 100, 500, and 1000 mA/g, denoting a 2×, and 12× capacity increase of those achieved in 3 M electrolytes at 500 and 1000 mA/g, respectively. A capacity retention rate of 73% was achieved after (dis)charging at 100 mA/g for 100 cycles, and no obvious capacity fading was observed at higher current densities of 500 mA/g and 2A/g. A compilation of structural and morphological characterization was systematically performed to provide insight into the mechanisms of the improved performance in ZnCl 2 WISE for the MoO3 cathode materials. Specifically, our data collectively suggested that the drastic fading in 3M electrolytes can be attributed to the parasitic surface deposits on Zn originated from Mo dissolution and H 2 formation due to Zn corrosion and hydrogen evolution reaction (HER), which were significantly suppressed in the ZnCl 2 WISE. The direct visualization of these side reactions was achieved for the first time in the Zn-MoO 3 system, using an in situ optoelectrochemical measurement.

25 ENERGY STORAGE↗
DOE OSTI2015

2 H and 139 La NMR Spectroscopy in Aqueous Solutions at Geochemical Pressures

Nuclear spin relaxation rates of 2 H and 139 La in LaCl 3 + 2 H 2 O and La(ClO 4 ) 3 + 2 H 2 O solutions were determined as a function of pressure in order to demonstrate a new NMR probe designed for solution spectroscopy at geochemical pressures. The 2 H longitudinal relaxation rates (T 1 ) vary linearly to 1.6 GPa, consistent with previous work at lower pressures. The 139 La T 1 values vary both with solution chemistry and pressure, but converge with pressure, suggesting that the combined effects of increased viscosity and enhanced rates of ligand exchange control relaxation. Furthermore, this simple NMR probe design allows experiments on aqueous solutions to pressures corresponding roughly to those at the base of the Earth’s continental crust.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2020

Unraveling the Dissolution-Mediated Reaction Mechanism of α-MnO 2 Cathodes for Aqueous Zn-Ion Batteries

Aqueous Zn/α-MnO 2 batteries have attracted immense interest owing to their high energy density, low cost, and safety, making them desirable for future large-scale energy application. Despite these merits, the comprehensive understanding of their reaction mechanism has been elusive due to the limitations of standard bulk characterization. Here, via transmission electron microscopy, the dissolution-mediated reaction mechanism of a Zn/α-MnO 2 system is discovered and explored in full scope to involve reversible formation of Zn 4 SO 4 (OH) 6 · x H 2 O and “birnessite-like” Zn-MnO x phase upon cycling. Overall, α-MnO 2 acts primarily as a source for cell activation through dissolution and thus is not directly involved in the Zn redox chemistry. Overall, this microscopic study offers a unique knowledge on the unconventional reaction chemistry of Zn/α-MnO 2 batteries.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗
DOE OSTI2019

Identification and Characterization of Herbicide Penoxsulam Transformation Products in Aqueous Media by UPLC-QTOF-MS

Photodegradation is an important non-biodegradation process of pesticide degradation in aquatic environments. In this study, the effect of different forms of nitrogen on the photodegradation kinetics of penoxsulam was investigated. The photodegradation of penoxsulam was accelerated by NO{sup 3−} and NO{sup 2−} but was not affected by NH{sup 4+}. Ultra-high-performance liquid chromatography coupled with time-of-flight mass spectrometry was used to separate and identify the transformation products (TPs)converted by photodegradation of penoxsulam in an aqueous solution under UV–Vis (290–800 nm) irradiation. Seven major transformation products were identified based on mass spectral data. The structure was determined by elemental composition calculations, comparison of structural analogs, and existing literature. The main pathways of photodegradation were found to be sulfonamide bond cleavage, rearrangement, triazole ring cleavage, and hydroxylation. These findings are critical to elucidate the environmental fate of penoxsulam in aquatic ecosystems and provide a basis for further environmental risk assessment.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2018

Annihilation Delayed Fluorescence of Indole and Its Derivatives in Aqueous Solution

Spectral and kinetic characteristics of annihilation delayed fluorescence (ADF) of indole and its derivatives (5-methylindole, N-methylindole) were measured in aqueous solutions at room temperature. ADF spectra of indole and 5-methylindole consisted of two bands with wavelength maxima at 350 and 425 nm for indole and 350 and 390 nm for 5-methylindole. The short-wavelength band was due to ADF of monomers and coincided with the fast fluorescence spectrum. The long-wavelength band was attributed to ADF of excimers, the excited singlet states of which were populated by annihilation of triplet excimers. Triplet states of excimers were formed by collisions of molecules in triplet and ground states. The ADF spectrum of N-methylindole consisted of only the short-wavelength ADF band of monomers (λ = 352 nm). Lifetimes of monomer and excimer triplet states were estimated from the ADF kinetics.

74 ATOMIC AND MOLECULAR PHYSICS↗
DOE OSTI2017

Quaternary Ammonium Polyamidoamine Dendrimer Modified Quantum Dots as Fluorescent Probes for p-Fluorophenoxyacetic Acid Detection in Aqueous Solution

The wide use of pesticide p-fluorophenoxyacetic acid has caused the serious environmental contaminant. A novel fluorescent probe for sensitive detection of p-fluorophenoxyacetic acid in aqueous solutions based on 3.0G quaternary ammonium polyamidoamine (PAMAM) dendrimer modified quantum dots (QDs) (PAMAM@QDs) was reported. Through the solvent-evaporation method, quaternary ammonium PAMAM was employed to modify the QDs. Poloxamer 188 was used to improve the solubility and stability. The resultant PAMAM@QDs dispersed well in water. Fluorescence (FL) spectroscopic study showed that the FL intensity of the PAMAM@QDs was enhanced in the presence of p-fluorophenoxyacetic acid. Under optimal conditions, the enhanced FL intensity as a function of concentration matched very well in the range of 1 ~ 200 µg/mL of p-fluorophenoxyacetic acid, while the lower limits of detection were found to be 0.16 µg/mL. These results show that PAMAM@QDs is a promising luminescent probe for the detection of pesticides.

74 ATOMIC AND MOLECULAR PHYSICS↗
DOE OSTI2017

Experimental and Modeling Studies for the Removal of Crystal Violet Dye from Aqueous Solutions using Eco-friendly Gracilaria corticata Seaweed Activated Carbon/Zn/Alginate Polymeric Composite Beads

This research article describes, an eco-friendly activated carbon prepared from the Gracilaria corticata seaweeds which was employed for the preparation of biodegradable polymeric beads for the efficient removal of crystal violet dye in an aqueous solution. The presence of chemical functional groups in the adsorbent material was detected using FTIR spectroscopy. The morphology and physical phases of the adsorbent materials were analyzed using SEM and XRD studies respectively. Batch mode dye adsorption behavior of the activated carbon/Zn/alginate polymeric beads was investigated as a function of dosage, solution pH, contact time, initial dye concentration and temperature. Maximum dye removal was observed at a pH of 5.0, 1 g of adsorbent dosage with 60 mg/L dye concentration, 50 min of contact time and at 30 °C. The equilibrium modeling studies were analyzed with Freundlich and Langmuir adsorption isotherms and the adsorption dynamics was predicted with Lagergren’s pseudo-first order, pseudo-second order equations and intra particle diffusion models. The process of dye removal followed a pseudo second-order kinetics rather than pseudo first order. The thermodynamic parameters like standard Gibbs free energy change (ΔG°), enthalpy change (ΔH°) and entropy change (ΔS°) were determined and the results imply that the adsorption process was spontaneous, endothermic and increases the randomness between the adsorbent and adsorbate. The results from the experimental and correlation data reveal that the Gracilaria corticata activated carbon/Zn/alginate polymeric beads have proved to be an excellent adsorbent material for the removal of CV dye.

36 MATERIALS SCIENCE↗
DOE OSTI2017

A Novel Polyester Fabric Treated with Nanoclay/Nano TiO{sub 2}/PAMAM for Discoloration of Reactive Red 4 from Aqueous Solution Under UVA Irradiation

Here, a commercially available absorbent with a high absorbance capacity (Cloisite{sup ®} 15A) together with the high active nano photocatalyst (AEROXIDE{sup ®} TiO{sub 2} P 25) and polyamidoamine based dendrimer (PAMAM) were immobilized on polyester fabric through simple pad-dry-cure method for removing dye from an aqueous solution. Using three components with good activities toward discoloration expected to produce a substrate with an excellent discoloration capacity. FESEM images with EDX patterns and X-ray diffraction spectra revealed the presence of nanoclay and nano TiO{sub 2} on the surface of the fabric. Discoloration of Reactive Red 4 (RR4) was carried out successfully by addition of a piece of the treated fabric in the dye solution under UVA irradiation. UV–visible spectra of the remaining solutions after discoloration indicated complete discoloration of RR4 solution for several times. The photocatalytic properties of the treated fabric was not changed after consecutive discoloration however the fabric surface was colored due to the presence of nanoclay on the surface acting as the dye absorbent. Graphical Abstract: .

36 MATERIALS SCIENCE↗
DOE OSTI2018

Reactive Dye Adsorption from Aqueous Solution on HPEI-Modified Fe{sub 3}O{sub 4} Nanoparticle as a Superadsorbent: Characterization, Modeling, and Optimization

In this work, the optimum condition for the adsorption of Reactive Blue 19 dye onto Fe{sub 3}O{sub 4} functionalized with hyperbranched polyethylenimine (Fe@HPEI) was determined using response surface methodology. The properties of synthesized magnetic Fe@HPEI nanoparticles were ascertained using FTIR, SEM, TEM, VSM and zeta potential measurement. The experimental adsorption data indicating the positive effect of adsorbent dose and contact time, and the negative effect of pH, initial dye concentration and ionic strength on dye adsorption. At optimal condition; pH 3.4, contact time 25 min, adsorbent dose 0.4 g/L and initial dye concentration 113 mg/L, Fe@HPEI nanoparticles removed dye up to 99.27%. The maximum experimental dye adsorption was near to the predicted value of 100%, which confirmed the reliability of the selected statistical model. The dye adsorption data were fitted well to Langmuir isotherm and pseudo-second-order kinetic, and the maximum adsorption capacity was 500 mg/g. Totally, Fe@HPEI as an effective superadsorbent can be repeatedly utilized for the adsorption of dye from the aqueous environment.

77 NANOSCIENCE AND NANOTECHNOLOGY↗
DOE OSTI2019

Physicochemical Behavior of Penaeuse semisulcatuse Chitin for Pb and Cd Removal from Aqueous Environment

A beta type-chitin was produced from the shell of Penaeuse semisulcatuse shrimp for removal of lead and cadmium from the aqueous environment. Full physicochemical properties of the chitin (FTIR, SEM, mapping, XRD, EDX, AFM, and TGA-DTG) were obtained. Effects of solution pH, chitin dose, metals concentration, and contact time on the lead and cadmium adsorption were assessed. The solution pH had a great influence on the metal removal. Pseudo-first and pseudo-second order models were used to evaluate the kinetic behavior of metals adsorption by P. semisulcatuse chitin. Freundlich isotherm model was slightly better than the Langmuir model to describe the adsorption data. The R{sub L} value (obtained from the Langmuir model) for the adsorption of lead and cadmium was calculated to be 0.027 and 0.133, respectively, which showed the metals adsorption process by the chitin is desirable. The maximum adsorption capacity of lead and cadmium by P. semisulcatuse chitin was determined 13.14 mg/g and 19.15 mg/g, respectively. To desorb the adsorbed-metal from the chitin, the 1M HNO{sub 3} solution was applied and the heavy metals desorption was suitable (90%). The half life (t{sub 1/2}) factor in the adsorption of Pb and Cd onto chitin was calculated 2.817 min and 3.876 min, respectively.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2019

Microfluidic Fabrication of Nanoparticles Based on Ethyl Acrylate-Functionalized Chitosan for Adsorption of Methylene Blue from Aqueous Solutions

The adsorption of nanoparticle (NP)-based adsorbents especially those made of polymers to remove dyes as toxic substances from pollutants is yet remained as a critical issue. The objective of this work was to prepare microfluidic (MF) fabrication of NPs based on ethyl acrylate (EA)-functionalized chitosan (CS) for methylene blue (MB) dye removal from aqueous solutions. For this purpose, a series of experiments such as FTIR, SEM alongside DLS, and UV–vis spectrophotometry were carried out to investigate the physicochemical properties of the samples. The FTIR spectra showed that the amine (–NH{sub 2}) and hydroxyl (–OH) groups on CS structure were replaced with EA, appropriately. The SEM and DLS results depicted that EA-functionalized CS NPs fabricated using MF technique had uniform shapes, and the diameters as small as 70 nm compared to those samples produced via bulk mixing (BM) method (~ 300 nm). Moreover, the surface charge of MF-assisted CS NPs after functionalization exhibited the lower zeta potential value (~ + 11) than that of samples based on BM (~ + 14) due to occurring the laminar flow through the micro-channels embedded in the MF chip, leading to an increase in the MB adsorption. Subsequently, at the optimized amounts of the dye concentration (89.12 mg L{sup −1}), the adsorbent concentration (1.38 g L{sup −1}), and pH (10.58) by means of Box-Behnken design (BBD) method, the maximum percentage of MB removal by the use of MF-fabricated EA-functionalized CS NPs was 98.4%. By fitting the obtained adsorption data to the isotherm models such as Lagmuir, Freundlich, and Temkin, it has been found that the adsorption mechanism followed the Langmuir model (maximum capacity of the adsorption 384.61 mg/g), which assumed a monolayer coverage of MB molecules as adsorbates over a homogeneous adsorbent surface.

36 MATERIALS SCIENCE↗
DOE OSTI2019

Synthesis and Characterization of Magnetic Halloysite–Alginate Beads for the Removal of Lead(II) Ions from Aqueous Solutions

In this study, alginate (ALG) hybrid spheres supported with magnetic halloysite nanotubes (MHNTs) were synthesized and used effectively in the removal of Pb(II) ions from aqueous solutions. MHNTs were prepared using the “co-precipitation” method. Afterward, magnetic halloysite–alginate (MHNT–ALG) hybrid beads were formed using ALG and MHNTs by the “extrusion dripping” method. The characterization of halloysite nanotubes (HNTs), ALG, MHNTs, and MHNT–ALG hydrogels was performed using FTIR, TGA, particle size analysis, SEM–EDX, TEM, VSM, and BET. According to VSM measurements, the saturation magnetization values of MHNTs and MHNT–ALG hybrid beads at a mass ratio of 1:2 were determined to be 22.7 emu/g and 8.17 emu/g, respectively. The BET surface area of MHNT–ALG hybrid beads was measured to be 81.3 m{sup 2}/g. The adsorption of Pb(II) ions on MHNT–ALG hydrogels was investigated as a function of the pH of the medium, amount of MHNT–ALG, the mass ratio of MHNT to ALG in the composite, and initial Pb(II) concentration in batch stirred vessels. The fit of the adsorption equilibrium of Pb(II) ions on MHNT–ALG hydrogels to the Langmuir type-I and type-II models, Freundlich model, and Redlich–Peterson model was investigated. The fit of the adsorption kinetics to the pseudo-second-order kinetics model was evaluated. Using the Weber and Morris model, the effect of internal and external diffusion limitations was discussed.

36 MATERIALS SCIENCE↗