Engineering Papers⌕ Search

SEARCH · Engineering Papers

Results for “Np”

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 253 records · Page 14
All sourcesNASA NTRSDOE OSTI
DOE OSTI2020

Nonmonotonic Strain Rate Dependence on the Strain Hardening of Polymer Nanocomposites

This Letter investigates the external deformation on modifying the polymer–nanoparticle (NP) and NP–NP interactions as well as their influences on the macroscopic properties of polymer nanocomposites (PNCs). Specifically, the applied uniaxial extension brings together the NPs along the transverse stretching direction and catalyzes the percolation transition from the initially well-dispersed NPs in the PNCs. The percolated NP network thus increases the strength of PNCs and leads to a strong surge in the elongation viscosity at very low strain rates, exhibiting the unexpected nonmonotonic strain rate dependence on the strain hardening. These results reveal explicitly the unconventional roles of the external deformation on modulating the relative strength of the polymer–NP and the NP–NP interactions, enabling advanced structures and properties control of PNCs.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2022

Surfactant Engineering and Its Role in Determining the Performance of Nanoparticulate Organic Photovoltaic Devices

The fabrication of organic photovoltaics (OPVs) from non-hazardous nanoparticulate (NP) inks offers considerable promise for the development of ecofriendly large-scale printed solar modules. However, the typical NP core-shell morphology (driven by the different donor/acceptor affinities for the surfactant used in NP synthesis) currently hinders the photovoltaic performance. As such, surfactant engineering offers an elegant approach to synthesizing a more optimal intermixed NP morphology and hence an improved photovoltaic performance. In this work, the morphology of conventional sodium dodecyl sulfate (SDS) and 2-(3-thienyl) ethyloxybutylsulfonate (TEBS)-stabilized poly(3-hexylthiophene) (P3HT) donor:phenyl-C 61 -butyric acid methyl ester (PC 61 BM) acceptor NPs is probed using scanning transmission X-ray microscopy, UV-vis spectroscopy, grazing-incidence X-ray diffraction, and scanning electron microscopy. While the SDS-stabilized NPs exhibit a size-independent core-shell morphology, this work reveals that TEBS-stabilized NPs deliver an intermixed morphology, the extent of which depends on the particle size. Consequently, by optimizing the TEBS-stabilized NP size and distribution, NP-OPV devices with a power conversion efficiency that is ~50% higher on average than that of the corresponding SDS-based NP-OPV devices are produced.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2026

Structural and mechanistic insights into protective non-neutralizing antibodies targeting Crimean-Congo hemorrhagic fever virus nucleocapsid protein

Abstract Crimean-Congo Hemorrhagic Fever Virus (CCHFV) is a tick-borne virus endemic to Africa, Asia, and expanding regions within Europe. With mortality rates approaching 40%, rising incidence, and no currently approved countermeasures, CCHFV is recognized as a priority public health threat. CCHFV nucleocapsid protein (NP) has long been a key target for diagnostics. Recently, NP-specific humoral responses have also been correlated with protection conferred by protective vaccines candidates. Additionally, the first non-neutralizing monoclonal antibody (mAb) 9D5 demonstrated protective efficacy against CCHFV challenge, underscoring NP as a viable antiviral target. Here, nine anti-NP mAb were utilized to identify four antigenic sites on NP as well as localize these sites to the head or stalk domains. These mAb also revealed variable levels of in vivo protection, independent from whether the epitope site is located in the head or stalk regions. Additionally, three X-ray crystallography structures were obtained that included CCHFV NP from strain Afg09-2990 in complex with the most potent mAb (9D5). This, along with additional structures of two unbound NPs, revealed structural elements critical for mAb-9D5 broad-spectrum protective characteristics. These findings provide a path towards the rapid identification of broadly protective anti-NP mAb countermeasures.

Moresco, Vanessa↗
DOE OSTI2024

Crimean Congo hemorrhagic fever virus nucleoprotein and GP38 subunit vaccine combination prevents morbidity in mice

Immunizing mice with Crimean-Congo hemorrhagic fever virus (CCHFV) nucleoprotein (NP), glycoprotein precursor (GPC), or with the GP38 domain of GPC, can be protective when the proteins are delivered with viral vectors or as a DNA or RNA vaccine. Subunit vaccines are a safe and cost-effective alternative to some vaccine platforms, but Gc and Gn glycoprotein subunit vaccines for CCHFV fail to protect despite eliciting high levels of neutralizing antibodies. Here, we investigated humoral and cellular immune responses and the protective efficacy of recombinant NP, GP38, and GP38 forms (GP85 and GP160) associated with the highly glycosylated mucin-like (MLD) domain, as well as the NP + GP38 combination. Vaccination with GP160, GP85, or GP38 did not confer protection, and vaccination with the MLD-associated GP38 forms blunted the humoral immune responses to GP38, worsened clinical chemistry, and increased viral RNA in the blood compared to the GP38 vaccination. In contrast, NP vaccination conferred 100% protection from lethal outcome and was associated with mild clinical disease, while the NP + GP38 combination conferred even more robust protection by reducing morbidity compared to mice receiving NP alone. Thus, recombinant CCHFV NP alone is a promising vaccine candidate conferring 100% survival against heterologous challenge. Moreover, incorporation of GP38 should be considered as it further enhances subunit vaccine efficacy by reducing morbidity in surviving animals.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2022

Characterizing the effect of incrementally increasing dry bulb temperature on linear and nonlinear measures of heart rate variability in nonpregnant, mid-gestation, and late-gestation sows

Abstract Characterizing the sow physiological response to an increased heat load is essential for effective heat stress mitigation. The study objective was to characterize the effects of a 400-min heating episode on sow heart rate variability (HRV) at different reproductive stages. HRV is a commonly used noninvasive proxy measure of autonomic function. Twenty-seven sows were enrolled in the study according to their gestation stage at time of selection: 1) nonpregnant (NP; n = 7), 2) mid-gestation (MID; 57.3 ± 11.8 d gestation; n = 11), and 3) late-gestation (LATE; 98.8 ± 4.9 d gestation; n = 8). The HRV data utilized in the study were collected from each pig as the dry bulb temperature in the room increased incrementally from 19.84 ± 2.15 °C to 35.54 ± 0.43 °C (range: 17.1–37.5 °C) over a 400-min period. After data collection, one 5-min set of continuous heart rate data were identified per pig for each of nine temperature intervals (19–20.99, 21–22.99, 23–24.99, 25–26.99, 27–28.99, 29–30.99, 31–32.99, 33–34.99, and 35–36.99 °C). Mean inter-beat interval length (RR), standard deviation of r-r intervals (SDNN), root mean square of successive differences (RMSSD), high frequency spectral power (HF), sample entropy (SampEn), short-term detrended fluctuation analysis (DFAα1), and three measures (%REC, DET, LMEAN) derived from recurrence quantification analysis were calculated for each data set. All data were analyzed using the PROC GLIMMIX procedure in SAS 9.4. Overall, LATE sows exhibited lower RR than NP sows (P < 0.01). The standard deviation of r–r intervals and RMSSD differed between each group (P < 0.01), with LATE sows exhibiting the lowest SDNN and RMSSD and NP sows exhibiting the greatest SDNN and RMSSD. Late-gestation sows exhibited lower HF than both MID and NP sows (P < 0.0001), greater DFA values than NP sows (P = 0.05), and greater DET compared to MID sows (P = 0.001). Late-gestation also sows exhibited greater %REC and LMEAN compared to MID (P < 0.01) and NP sows (all P < 0.01). In conclusion, LATE sows exhibited indicators of greater autonomic stress throughout the heating period compared to MID and NP sows. However, temperature by treatment interactions were not detected as dry bulb increased. Future studies are needed to fully elucidate the effect of gestational stage and increasing dry bulb temperature on sow HRV.

Agriculture↗
DOE OSTI2025

Inspection of next-generation EUV resists with nano-projectile secondary ion mass spectrometry

There is a rapidly growing need for new materials for extreme ultraviolet (EUV) lithography, which incorporate high EUV absorbing elements. Hybrid resists, which are a combination of inorganic and organic moieties, are promising as they offer both high EUV sensitivity and high etch resistance. However, there is a glaring lack of methods to examine the uniformity of these important materials at the nanoscale. We examine the capabilities of nano-projectile secondary ion mass spectrometry (NP-SIMS) to investigate hybrid resists. NP-SIMS is a mass spectrometry-based technique with high lateral resolution. Using NP-SIMS, a surface is probed stochastically with a suite of individual projectiles, 10 6 to 10 7 in total, separated in time and space. Examining these individual mass spectra allows for nanoscale investigation of the uniformity of the surface. We evaluated the performance of NP-SIMS using samples of poly(methyl methacrylate) (PMMA) infiltrated with varying amounts of InO x via vapor-phase infiltration (VPI), an organic–inorganic hybridization method derived from atomic layer deposition. Here, we found that NP-SIMS measurements contained abundant characteristic ions related to both the PMMA and infiltrated In. The intensity of In atomic ions increased linearly with the number of infiltration cycles; however, the uniformity of In and PMMA varied with the number of infiltration cycles. After one cycle, we found that both the PMMA and In were relatively inhomogeneous. The homogeneity improved with subsequent infiltration cycles. In addition, NP-SIMS measurements contained characteristic ions related to the infiltration reaction and provided insights into the VPI mechanism. Overall, the results show that NP-SIMS is capable of examining both the inorganic and organic moieties in a hybrid resist and will be an important method for understanding the performance of these materials for use in EUV lithography.

36 MATERIALS SCIENCE↗
DOE OSTI2024

The immune-evasive proline-283 substitution in influenza nucleoprotein increases aggregation propensity without altering the native structure

Nucleoprotein (NP) is a key structural protein of influenza ribonucleoprotein complexes and is central to viral RNA packing and trafficking. NP also determines the sensitivity of influenza to myxovirus resistance protein 1 (MxA), an innate immunity factor that restricts influenza replication. A few critical MxA-resistant mutations have been identified in NP, including the highly conserved proline-283 substitution. This essential proline-283 substitution impairs influenza growth, a fitness defect that becomes particularly prominent at febrile temperature (39°C) when host chaperones are depleted. Here, we biophysically characterize proline-283 NP and serine-283 NP to test whether the fitness defect is caused by the proline-283 substitution introducing folding defects. We show that the proline-283 substitution changes the folding pathway of NP, making NP more aggregation prone during folding, but does not alter the native structure of the protein. These findings suggest that influenza has evolved to hijack host chaperones to promote the folding of otherwise biophysically incompetent viral proteins that enable innate immune system escape.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2026

New approaches to Bayesian uncertainty quantification for Nuclear Science (Final Technical Report)

Inverse problems play a central role in experimentation and theory/data comparisons for many areas of modern Nuclear Physics (NP) and High-Energy Physics (HEP). Bayes’s Theorem is a powerful tool for solving Inverse Problems, providing conceptually transparent and unbiased constraints on theoretical parameters and their uncertainties (“Bayesian Inference”) and enabling the quantification of agreement or tension between models and data. However, analyses based on Bayesian Inference are often challenging for NP and HEP applications, either because of the large number of parameters in the problem, the high computational cost, or both. We propose a multi-institutional collaboration to develop and deploy novel Bayesian analysis tools that advance the scientific scope of a broad range of current and future NP experiments. This project brings together NP domain scientists working on several high-profile NP projects for which new, high-performance Bayesian Uncertainty Quantification (“Bayesian UQ”) methods are essential to carry out the science, and data scientists who are developing state-of-the-art methods applicable to these problems. The NP projects in this proposal comprise measurements of the mass and fundamental nature of the neutrino; study of the Quark-Gluon Plasma that filled the early universe; and mapping of natural and anthropogenic radiation environments. While these NP projects have very different scientific goals, with datasets and analysis approaches that differ significantly, they share common requirements for improving computationally intensive Bayesian analyses using advanced Machine Learning algorithms and will benefit strongly from a coherent effort to develop general solutions. This proposal brings together these projects and forefront ML-based data science algorithms to develop such general solutions. The methods developed in this project will also be more widely applicable, thereby advancing science in the larger Nuclear Physics portfolio.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗
DOE OSTI2020

Materials Data on NpFe2 by Materials Project

NpFe2 is Cubic Laves structured and crystallizes in the cubic Fd-3m space group. The structure is three-dimensional. Np is bonded in a 12-coordinate geometry to four equivalent Np and twelve equivalent Fe atoms. All Np–Np bond lengths are 2.96 Å. All Np–Fe bond lengths are 2.84 Å. Fe is bonded to six equivalent Np and six equivalent Fe atoms to form a mixture of corner, edge, and face-sharing FeNp6Fe6 cuboctahedra. All Fe–Fe bond lengths are 2.42 Å.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Zr2Np by Materials Project

NpZr2 crystallizes in the hexagonal P6/mmm space group. The structure is three-dimensional. Np is bonded in a 2-coordinate geometry to two equivalent Np and twelve equivalent Zr atoms. Both Np–Np bond lengths are 2.81 Å. All Np–Zr bond lengths are 3.33 Å. Zr is bonded in a 11-coordinate geometry to six equivalent Np and five equivalent Zr atoms. There are two shorter (2.81 Å) and three longer (3.02 Å) Zr–Zr bond lengths.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on NpMn2 by Materials Project

NpMn2 is Cubic Laves structured and crystallizes in the cubic Fd-3m space group. The structure is three-dimensional. Np is bonded in a 12-coordinate geometry to four equivalent Np and twelve equivalent Mn atoms. All Np–Np bond lengths are 3.01 Å. All Np–Mn bond lengths are 2.88 Å. Mn is bonded to six equivalent Np and six equivalent Mn atoms to form a mixture of face, edge, and corner-sharing MnNp6Mn6 cuboctahedra. All Mn–Mn bond lengths are 2.46 Å.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on NpGa2 by Materials Project

NpGa2 crystallizes in the hexagonal P6/mmm space group. The structure is three-dimensional. Np is bonded in a 12-coordinate geometry to two equivalent Np and twelve equivalent Ga atoms. Both Np–Np bond lengths are 2.88 Å. All Np–Ga bond lengths are 3.11 Å. Ga is bonded in a distorted q6 geometry to six equivalent Np and five equivalent Ga atoms. There are three shorter (2.76 Å) and two longer (2.88 Å) Ga–Ga bond lengths.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on NpSnIr by Materials Project

NpIrSn crystallizes in the hexagonal P-62m space group. The structure is three-dimensional. Np is bonded in a 11-coordinate geometry to five Ir and six equivalent Sn atoms. There are four shorter (3.01 Å) and one longer (3.06 Å) Np–Ir bond lengths. There are two shorter (3.18 Å) and four longer (3.35 Å) Np–Sn bond lengths. There are two inequivalent Ir sites. In the first Ir site, Ir is bonded in a 9-coordinate geometry to six equivalent Np and three equivalent Sn atoms. All Ir–Sn bond lengths are 2.81 Å. In the second Ir site, Ir is bonded in a 9-coordinate geometry to three equivalent Np and six equivalent Sn atoms. All Ir–Sn bond lengths are 2.76 Å. Sn is bonded in a 10-coordinate geometry to six equivalent Np and four Ir atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on NpAl2 by Materials Project

NpAl2 is Cubic Laves structured and crystallizes in the cubic Fd-3m space group. The structure is three-dimensional. Np is bonded in a 12-coordinate geometry to four equivalent Np and twelve equivalent Al atoms. All Np–Np bond lengths are 3.36 Å. All Np–Al bond lengths are 3.21 Å. Al is bonded to six equivalent Np and six equivalent Al atoms to form a mixture of corner, edge, and face-sharing AlNp6Al6 cuboctahedra. All Al–Al bond lengths are 2.74 Å.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Np3Al by Materials Project

Np3Al is Uranium Silicide structured and crystallizes in the cubic Pm-3m space group. The structure is three-dimensional. Np is bonded to eight equivalent Np and four equivalent Al atoms to form NpNp8Al4 cuboctahedra that share corners with twelve equivalent NpNp8Al4 cuboctahedra, edges with eight equivalent AlNp12 cuboctahedra, edges with sixteen equivalent NpNp8Al4 cuboctahedra, faces with four equivalent AlNp12 cuboctahedra, and faces with fourteen equivalent NpNp8Al4 cuboctahedra. All Np–Np bond lengths are 3.05 Å. All Np–Al bond lengths are 3.05 Å. Al is bonded to twelve equivalent Np atoms to form AlNp12 cuboctahedra that share corners with twelve equivalent AlNp12 cuboctahedra, edges with twenty-four equivalent NpNp8Al4 cuboctahedra, faces with six equivalent AlNp12 cuboctahedra, and faces with twelve equivalent NpNp8Al4 cuboctahedra.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Np3Tl by Materials Project

Np3Tl is Uranium Silicide structured and crystallizes in the cubic Pm-3m space group. The structure is three-dimensional. Np is bonded to eight equivalent Np and four equivalent Tl atoms to form NpNp8Tl4 cuboctahedra that share corners with twelve equivalent NpNp8Tl4 cuboctahedra, edges with eight equivalent TlNp12 cuboctahedra, edges with sixteen equivalent NpNp8Tl4 cuboctahedra, faces with four equivalent TlNp12 cuboctahedra, and faces with fourteen equivalent NpNp8Tl4 cuboctahedra. All Np–Np bond lengths are 3.29 Å. All Np–Tl bond lengths are 3.29 Å. Tl is bonded to twelve equivalent Np atoms to form TlNp12 cuboctahedra that share corners with twelve equivalent TlNp12 cuboctahedra, edges with twenty-four equivalent NpNp8Tl4 cuboctahedra, faces with six equivalent TlNp12 cuboctahedra, and faces with twelve equivalent NpNp8Tl4 cuboctahedra.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Np3Sn by Materials Project

Np3Sn is Uranium Silicide structured and crystallizes in the cubic Pm-3m space group. The structure is three-dimensional. Np is bonded to eight equivalent Np and four equivalent Sn atoms to form distorted NpNp8Sn4 cuboctahedra that share corners with twelve equivalent NpNp8Sn4 cuboctahedra, edges with eight equivalent SnNp12 cuboctahedra, edges with sixteen equivalent NpNp8Sn4 cuboctahedra, faces with four equivalent SnNp12 cuboctahedra, and faces with fourteen equivalent NpNp8Sn4 cuboctahedra. All Np–Np bond lengths are 3.25 Å. All Np–Sn bond lengths are 3.25 Å. Sn is bonded to twelve equivalent Np atoms to form SnNp12 cuboctahedra that share corners with twelve equivalent SnNp12 cuboctahedra, edges with twenty-four equivalent NpNp8Sn4 cuboctahedra, faces with six equivalent SnNp12 cuboctahedra, and faces with twelve equivalent NpNp8Sn4 cuboctahedra.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Np3In by Materials Project

Np3In is Uranium Silicide structured and crystallizes in the cubic Pm-3m space group. The structure is three-dimensional. Np is bonded to eight equivalent Np and four equivalent In atoms to form distorted NpNp8In4 cuboctahedra that share corners with twelve equivalent NpNp8In4 cuboctahedra, edges with eight equivalent InNp12 cuboctahedra, edges with sixteen equivalent NpNp8In4 cuboctahedra, faces with four equivalent InNp12 cuboctahedra, and faces with fourteen equivalent NpNp8In4 cuboctahedra. All Np–Np bond lengths are 3.24 Å. All Np–In bond lengths are 3.24 Å. In is bonded to twelve equivalent Np atoms to form InNp12 cuboctahedra that share corners with twelve equivalent InNp12 cuboctahedra, edges with twenty-four equivalent NpNp8In4 cuboctahedra, faces with six equivalent InNp12 cuboctahedra, and faces with twelve equivalent NpNp8In4 cuboctahedra.

36 MATERIALS SCIENCE↗