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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 1,441 records · Page 80

One-dimensional alignment of defects in a flexible metal-organic framework

Crystalline materials are often considered to have rigid periodic lattices, while soft materials are associated with flexibility and nonperiodicity. The continuous evolution of metal-organic frameworks (MOFs) has erased the boundaries between these two distinct conceptions. Flexibility, disorder, and defects have been found to be abundant in MOF materials with imperfect crystallinity, and their intricate interplay is poorly understood because of the limited strategies for characterizing disordered structures. Here, we apply advanced nuclear magnetic resonance spectroscopy to elucidate the mesoscale structures in a defective MOF with a semicrystalline lattice. We show that engineered defects can tune the degree of lattice flexibility by combining both ordered and disordered compartments. The one-dimensional alignment of correlated defects is the key for the reversible topological transition. The unique matrix is featured with both rigid framework of nanoporosity and flexible linkage of high swellability.

36 MATERIALS SCIENCE↗

Quantifying Stern layer water alignment before and during the oxygen evolution reaction

While water’s oxygen is the electron source in the industrially important oxygen evolution reaction, the strong absorber problem clouds our view of how the Stern layer water molecules orient themselves in response to applied potentials. Here, we report nonlinear optical measurements on nickel electrodes held at pH 13 indicating a disorder-to-order transition in the Stern layer water molecules before the onset of Faradaic current. A full water monolayer (1.1 × 10 15 centimeter −2 ) aligns with oxygen atoms pointing toward the electrode at +0.8 volt and the associated work is 80 kilojoule per mole. Our experiments identify water flipping energetics as a target for understanding overpotentials, advance molecular electrochemistry, provide benchmarks for electrical double layer models, and serve as a diagnostic tool for understanding electrocatalysis.

Science & Technology - Other Topics↗

Autonomous alignment and healing in multilayer soft electronics using immiscible dynamic polymers

Self-healing soft electronic and robotic devices can, like human skin, recover autonomously from damage. While current devices use a single type of dynamic polymer for all functional layers to ensure strong interlayer adhesion, this approach requires manual layer alignment. In this study, we used two dynamic polymers, which have immiscible backbones but identical dynamic bonds, to maintain interlayer adhesion while enabling autonomous realignment during healing. These dynamic polymers exhibit a weakly interpenetrating and adhesive interface, whose width is tunable. When multilayered polymer films are misaligned after damage, these structures autonomously realign during healing to minimize interfacial free energy. Finally, we fabricated devices with conductive, dielectric, and magnetic particles that functionally heal after damage, enabling thin-film pressure sensors, magnetically assembled soft robots, and underwater circuit assembly.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗

On the possible common nature of double extensive air showers and aligned events

Double extensive air showers and aligned events at energies in the region E Greater-Than-Or-Equivalent-To 10{sup 16} eV were discovered more than a quarter of a century ago. However, there is still no satisfactory explanation of their nature. In the present study, it is assumed that these two types of events have common nature, stemming from the break of a string that arises in the interaction of ultrahigh-energy particles.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗

Orientation features of {sup 24}Mg(2+) aligned nuclei in (p, p) and (d, d) reactions at E{sub x} ≈ 7.5 MeV per nucleon

Experimental angular dependences of cross sections for elastic and inelastic scattering and the result obtained by reconstructing the populations of magnetic sublevels, multipole-moment orientation tensors, and polarization tensors are presented for {sup 24}Mg (2{sup +}, 1.369 MeV) aligned nuclei produced in inelastic proton scattering at E{sub p} = 7.4 MeV. The experimental results in question are compared with the results of calculations based on the coupled-channel method and on the compound-nucleus model, the 3/2{sup +} resonance in the {sup 25}Al compound nucleus being taken into account. The orientation features of {sup 24}Mg (2{sup +}, 1.369 MeV) nuclei produced in inelastic proton and deuteron scattering on {sup 24}Mg at E{sub x} ≈ 7.5 MeV per nucleon are found to be generally similar despite a substantial difference in the respective differential cross sections.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗

Aligned interactions in cosmic rays

The first clean Centauro was found in cosmic rays years many ago at Mt Chacaltaya experiment. Since that time, many people have tried to find this type of interaction, both in cosmic rays and at accelerators. But no one has found a clean cases of this type of interaction.It happened finally in the last exposure of emulsion at Mt Chacaltaya where the second clean Centauro has been found. The experimental data for both the Centauros and STRANA will be presented and discussed in this paper. We also present our comments to the intriguing question of the existence of a type of nuclear interactions at high energy with alignment.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗

Polarization Properties of Photoluminescence of Anisotropic Polymer Films Containing Aligned Au Nanorods and Semiconductor Nanoparticles of Various Shape

Anisotropic polymer films containing aligned Au nanorods and semiconductor nanoparticles of various shape were fabricated. The photoluminescence of semiconductor nanoparticles in these films is partially polarized. The value of the photoluminescence polarization degree of quantum dots embedded in an anisotropic PVA-film after 4.5-fold stretching P = 0.27 has been obtained.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗

Vertically Aligned Carbon Nanofiber based Biosensor Platform for Glucose Sensor

Vertically aligned carbon nanofibers (VACNFs) have recently become an important tool for biosensor design. Carbon nanofibers (CNF) have excellent conductive and structural properties with many irregularities and defect sites in addition to exposed carboxyl groups throughout their surfaces. These properties allow a better immobilization matrix compared to carbon nanotubes and offer better resolution when compared with the FET-based biosensors. VACNFs can be deterministically grown on silicon substrates allowing optimization of the structures for various biosensor applications. Two VACNF electrode architectures have been employed in this study and a comparison of their performances has been made in terms of sensitivity, sensing limitations, dynamic range, and response time. The usage of VACNF platform as a glucose sensor has been verified in this study by selecting an optimum architecture based on the VACNF forest density. Read More: http://www.worldscientific.com/doi/abs/10.1142/S0129156414500062

Al Mamun, Khandaker A.↗

Fabrication and Characterization of Self-aligned InAlAs/InGaAsSb/InGaAs Double Heterojunction Bipolar Transistors

A trilevel resist system was employed to fabricate self-aligned,submicron emitter finger In0.52Al0.48As/In0.42Ga0.58As0.77Sb0.23/In0.53Ga0.47As double heterojunction bipolar transistors (DHBTs).Selective wet-etchants were used to define the emitter fingers andto form an InGaAs guard-ring around the emitter fingers. Due tothe low energy bandgap of the InGaAsSb base layer and type IIbase-collector junction, a low turn-on voltage of 0.38 V at 1 A/cm2and a high dc current gain of 123.8 for a DHBT with a 0.65 × 8.65μm2 emitter area were obtained. A unity gain cut-off frequency(fT) of 260 GHz and a maximum oscillation frequency (fmax) of 485GHz at JC = 302 kA/cm2 were achieved.

47 OTHER INSTRUMENTATION↗

Electrode Degradation Study of Vertically Aligned Carbon Nanotubes on a 3D Integrated Current Collector

Assembling nanostructured materials into rationally designed mesoscale arrays for use as electrodes in electrochemical systems is anticipated to reveal new challenges, particularly concerning new synthesis modes, architecture-related performance limitations, and degradation mechanisms. In this work, we focus on characterizing the degradation of densely packed vertically aligned carbon nanotubes (VACNTs) grown directly on a metallic foam to form a self-supporting, hierarchically porous 3D electrode architecture with an integrated current collector. The degradation pathways of this electrode, observed with microscopy and semi in-situ XPS after cycling as a redox scaffold in aprotic Li—O2 and Li—S batteries, shed new light on important design, performance, and degradation considerations for integrated mesoscale electrode architectures.

36 MATERIALS SCIENCE↗

Alignment Implementation for Manufacturing using Fringe Analysis Slope Technique (AIMFAST) 2018.11.20

AIMFAST is a software code used to align facets on a dish or heliostat solar concentrator to a specific aimpoint strategy to minimize peak fluxes and maximize system optical performance. AIMFAST uses a large monitor or projection screen to display fringe patterns, and a machine vision camera to image the reflection of these patterns in the subject dish mirrors. From these images, a detailed map of surface normals can be generated and compared to design or fitted mirror shapes. This fitted comparison is then used to develop a single vector representing the orientation of the facets relative to the design orientation and provide near-real-time adjustment information to a communicating computer. The communicating computer can display adjustments or directly interface with adjustment tools.

Yellowhair, Julius↗

Sample Code for "An automated approach to the alignment of compound refractive lenses"

This sample code is intended to be publicly released on DOECODE. It is an accompaniment to "n automated approach to the alignment of compoundrefractive lenses". It's two small, mostly self-contained scripts that include the complete details necessary to implement the to-be published article's algorithm at a scientific beamline.

Breckling, SeanR [Mission Support and Test Service↗

Cyber Knowledge Alignment

An automated workflow and introduces new approaches to curate existing cybersecurity knowledge from multiple sources. It also proposes AI/ML-based methods to infer knowledge alignments across different repositories.

Purohit, Sumit [Pacific Northwest National Laborat↗

Robot-Alignment

Fermilab's SRF Robotics group's automated alignment program. FERMILAB-CODE-2026-03-TD

Giffen, Nickolas [Northern Illinois Univ., DeKalb,↗

Designing a graphics processing unit accelerated petaflop capable lattice Boltzmann solver: Read aligned data layouts and asynchronous communication

The lattice Boltzmann method is a well-established numerical approach for complex fluid flow simulations. Recently, general-purpose graphics processing units (GPUs) have become available as high-performance computing resources at large scale. We report on designing and implementing a lattice Boltzmann solver for multi-GPU systems that achieves 1.79 PFLOPS performance on 16,384 GPUs. To achieve this performance, we introduce a GPU compatible version of the so-called bundle data layout and eliminate the halo sites in order to improve data access alignment. Furthermore, we make use of the possibility to overlap data transfer between the host central processing unit and the device GPU with computing on the GPU. As a benchmark case, we simulate flow in porous media and measure both strong and weak scaling performance with the emphasis being on large-scale simulations using realistic input data.

Computer Science↗

Alignment-free genome comparison enables accurate geographic sourcing of white oak DNA

Background: The application of genomic data and bioinformatics for the identification of restricted or illegally-sourced natural products is urgently needed. The taxonomic identity and geographic provenance of raw and processed materials have implications in sustainable-use commercial practices, and relevance to the enforcement of laws that regulate or restrict illegally harvested materials, such as timber. Improvements in genomics make it possible to capture and sequence partial-to-complete genomes from challenging tissues, such as wood and wood products. Results: In this paper, we report the success of an alignment-free genome comparison method, d 2; that differentiates different geographic sources of white oak (Quercus) species with a high level of accuracy with very small amount of genomic data. The method is robust to sequencing errors, different sequencing laboratories and sequencing platforms. Conclusions: This method offers an approach based on genome-scale data, rather than panels of pre-selected markers for specific taxa. The method provides a generalizable platform for the identification and sourcing of materials using a unified next generation sequencing and analysis framework.

59 BASIC BIOLOGICAL SCIENCES↗

Smart align -- A new tool for robust non-rigid registration of scanning microscope data

Many microscopic investigations of materials may benefit from the recording of multiple successive images. This can include techniques common to several types of microscopy such as frame averaging to improve signal-to-noise ratios (SNR) or time series to study dynamic processes or more specific applications. In the scanning transmission electron microscope, this might include focal series for optical sectioning or aberration measurement, beam damage studies or camera-length series to study the effects of strain; whilst in the scanning tunnelling microscope, this might include bias voltage series to probe local electronic structure. Whatever the application, such investigations must begin with the careful alignment of these data stacks, an operation that is not always trivial. In addition, the presence of low-frequency scanning distortions can introduce intra-image shifts to the data. Here, we describe an improved automated method of performing non-rigid registration customised for the challenges unique to scanned microscope data specifically addressing the issues of low-SNR data, images containing a large proportion of crystalline material and/or local features of interest such as dislocations or edges. Careful attention has been paid to artefact testing of the non-rigid registration method used, and the importance of this registration for the quantitative interpretation of feature intensities and positions is evaluated.

36 MATERIALS SCIENCE↗