Search NASASearch

SEARCH · Search NASA

Results for “template”

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 181 records · Page 10

Templated native silk smectic gels

One aspect of the present invention relates to a method of preparing a fibrous protein smectic hydrogel by way of a solvent templating process, comprising the steps of pouring an aqueous fibrous protein solution into a container comprising a solvent that is not miscible with water; sealing the container and allowing it to age at about room temperature; and collecting the resulting fibrous protein smectic hydrogel and allowing it to dry. Another aspect of the present invention relates to a method of obtaining predominantly one enantiomer from a racemic mixture, comprising the steps of pouring an aqueous fibrous protein solution into a container comprising a solvent that is not miscible with water; sealing the container and allowing it to age at about room temperature; allowing the enantiomers of racemic mixture to diffuse selectively into the smectic hydrogel in solution; removing the smectic hydrogel from the solution; rinsing predominantly one enantiomer from the surface of the smectic hydrogel; and extracting predominantly one enantiomer from the interior of the smectic hydrogel. The present invention also relates to a smectic hydrogel prepared according to an aforementioned method.

Jin, Hyoung-Joon

I Zw 18, a Template for Star-Forming, z is Greater than 7 Galaxies

I Zw 18-NW, one of the most primitive nearby dwarf galaxies, is arguably the best template we have for star-forming, very high-redshift galaxies (z>7). We have therefore obtained a far-UV spectrum of I Zw 18-NW using Hubble's Cosmic Origins Spectrograph (COS). The spectrum indicates star-formation over the past approx.10 Myr, a very low stellar metallicity, log Z/Zsun approx. -1.7, and high average stellar rotation rate, Vsini approx.200 km/s. Stellar wind lines are very weak, and the edge velocity of wind lines is very low (approx.250 km/s). The overall properties of I Zw 18-NW are consistent with theories of very low metallicity, rapidly rotating stars, e.g. Meynet et al. (2006).

Heap, Sara R.

Software Template for Instruction in Mathematics

Intelligent Math Tutor (IMT) is a software system that serves as a template for creating software for teaching mathematics. IMT can be easily connected to artificial-intelligence software and other analysis software through input and output of files. IMT provides an easy-to-use interface for generating courses that include tests that contain both multiple-choice and fill-in-the-blank questions, and enables tracking of test scores. IMT makes it easy to generate software for Web-based courses or to manufacture compact disks containing executable course software. IMT also can function as a Web-based application program, with features that run quickly on the Web, while retaining the intelligence of a high-level language application program with many graphics. IMT can be used to write application programs in text, graphics, and/or sound, so that the programs can be tailored to the needs of most handicapped persons. The course software generated by IMT follows a "back to basics" approach of teaching mathematics by inducing the student to apply creative mathematical techniques in the process of learning. Students are thereby made to discover mathematical fundamentals and thereby come to understand mathematics more deeply than they could through simple memorization.

Shelton, Robert O.

Templated Native Silk Smectic Gels

One aspect of the present invention relates to a method of preparing a fibrous protein smectic hydrogel by way of a solvent templating process, comprising the steps of pouring an aqueous fibrous protein solution into a container comprising a solvent that is not miscible with water; sealing the container and allowing it to age at about room temperature; and collecting the resulting fibrous protein smectic hydrogel and allowing it to dry. Another aspect of the present invention relates to a method of obtaining predominantly one enantiomer from a racemic mixture, comprising the steps of pouring an aqueous fibrous protein solution into a container comprising a solvent that is not miscible with water; sealing the container and allowing it to age at about room temperature; allowing the enantiomers of racemic mixture to diffuse selectively into the smectic hydrogel in solution; removing the smectic hydrogel from the solution; rinsing predominantly one enantiomer from the surface of the smectic hydrogel; and extracting predominantly one enantiomer from the interior of the smectic hydrogel. The present invention also relates to a smectic hydrogel prepared according to an aforementioned method.

Jin, Hyoung-Joon

Templated Native Silk Smectic Gels

One aspect of the present invention relates to a method of preparing a fibrous protein smectic hydrogel by way of a solvent templating process, comprising the steps of pouring an aqueous fibrous protein solution into a container comprising a solvent that is not miscible with water; sealing the container and allowing it to age at about room temperature; and collecting the resulting fibrous protein smectic hydrogel and allowing it to dry. Another aspect of the present invention relates to a method of obtaining predominantly one enantiomer from a racemic mixture, comprising the steps of pouring an aqueous fibrous protein solution into a container comprising a solvent that is not miscible with water; sealing the container and allowing it to age at about room temperature; allowing the enantiomers of racemic mixture to diffuse selectively into the smectic hydrogel in solution; removing the smectic hydrogel from the solution; rinsing predominantly one enantiomer from the surface of the smectic hydrogel; and extracting predominantly one enantiomer from the interior of the smectic hydrogel. The present invention also relates to a smectic hydrogel prepared according to an aforementioned method.

Jin, Hyoung-Joon

Optimizing Surfactant Templating of Yttria-stabilized Zirconia Aerogels for High-temperature Applications: Effect of Anionic & Nonionic Surfactant

Aerogels are useful thermal insulators due to low density, low thermal conductivity, and a tortuous path for solid conduction. However, the formulation must be optimized to increase thermal stability as drastic densification and surface area decrease is often exhibited after high-temperature exposure. Current research investigates yttria-stabilized zirconia (YSZ) aerogels for expected use between 600°C and 1000°C. We anticipate that new sol-gel chemistries will yield YSZ aerogels with retained mesoporous structure, increased surface area, and minimized shrinkage upon high-temperature exposure. This work investigates the anionic surfactant, sodium dodecyl sulfate (SDS), and the nonionic surfactant, Pluronic® P-123, as templating agents to prevent the collapse of the aerogel pore structure upon gelation and drying. To determine the effect of surfactant, characterization techniques such as nitrogen physisorption, x-ray diffraction, and scanning electron microscopy are used. By optimizing surfactant concentration, the thermal stability of YSZ aerogels can be enhanced, producing more efficient thermal insulators.

Rebecca C. Walker

A new template for developing C++ applications in NASA's Core Flight System

In this presentation, we will demonstrate an example Core Flight System (cFS) application written in C++, compatible with the Draco releases of the Core Flight Executive (cFE) and NASA Operating System Abstraction Layer (OSAL). The application boilerplate, supporting library, and associated generation script were recently developed and licensed under the permissive Apache License 2.0 with the goal of easing the cFS app development with C++. The design and features of this application will be presented, including a higher-level interface for interactions with the cFE software bus pipes, tables, and event services. Data structures are provided for centralized telecommand and telemetry parsing which isolates bookkeeping of message components from the calling code in an application's core logic. Specific advantages of writing a cFS application in C++ will be shown, including easier avoidance of symbol collisions via namespaces, expanded compile-time checks via constant expressions, default initialization for data structures, null safety via references, improved syntax for operating on multi-dimensional arrays, and reliable serialization of enumerations via enumeration classes. Special considerations needed for integrating a C++ application will be identified, including function linkage, exceptions, and stack unwinding. Evidence for the usefulness of this template will be discussed in the context of development of a flight software application used for interfacing with a solid-state data recorder.

Dominick Allen

RAVEN Template for Dynamic Representativity Analysis of the High Temperature Test Facility

These slides present a walkthrough of the template that has been developed for using RAVEN to perform representativity analysis using models of the High Temperature Test Facility and the General Atomics Modular High Temperature Gas-cooled Reactor. The presentation provides participants in the HTTF benchmark with a walkthrough on how to use RAVEN for their sensitivity analysis and how to read results from the MHTGR-350 to perform representativity

22 - GENERAL STUDIES OF NUCLEAR REACTORS

Self‐Assembled Monolayer Templating for Engineered Nanopinholes in Passivated Contact Solar Cells

We present a novel self-assembled monolayer (SAM)-based technique to make nanopinhole-enabled passivated contacts on silicon solar cells by tuning the SAM coverage area and etch selectivity. We deposit trimethyl-silyl Si(CH 3 ) 3 groups using hexamethyldisilazane (HMDS) as the precursor over passivating dielectric layers and their stacks (SiO 2 , SiN x , SiO 2 /SiN x ) and interrupt the HMDS attachment chemistry shortly before a full monolayer is formed on its surface. Subsequent etching in dilute HF produces pinholes through the dielectric layers due to the higher etch resistance of the SAM to HF etching. The pinhole areal density (10 4 –10 8 /cm 2 ) and size (10–1000 nm) can be tuned both by duration of HMDS attachment and HF etch time. Pinholes were characterized by atomic force microscopy, tetramethylammonium hydroxide (TMAH) selective etch, and Ag decoration by electroless plating. Polysilicon (poly-Si) passivated contacts enabled by pinholes were formed by subsequent deposition of doped amorphous silicon (a-Si:H) followed by thermal crystallization and dopant drive-in. At optimal areal pinhole density ≈10 7 /cm 2 , contacts exhibit both passivation and carrier transport via pinholes as evidenced by electron beam induced current, transmission line measurements, and carrier lifetime measurements. Solar cells based with these pinhole contacts show V oc = 723 mV and FF = 80.3%. The remaining SAM layer does not affect device performance.

14 SOLAR ENERGY

DNA Crystals as a Template for Patterned Functional Materials

DNA nanotechnology offers a wide toolkit of molecular functionalities and scales, including intricate motifs less than 10 nm and periodic structures exceeding 100 µm. At larger scales, however, there are often significant tradeoffs for DNA structures, namely stability and mechanical strength. This work describes the design, synthesis, and characterization of a functionalized DNA crystal. Using a ligated DNA crystal grants significant freedom for various functional materials to be applied, in this case, semiconducting cadmium sulfide and palladium metal. Properties investigated in this study include stability, mechanical strength, and optoelectronic properties such as photoluminescence (PL) and electric conductivity. Significant changes are observed based on the functional material applied to DNA crystals. The Young's modulus of the crystal varies by about five orders of magnitude when functionalized with palladium. PL and semiconductive behaviors were observed when cadmium sulfide was attached. These crystals represent an expansion of the capabilities of DNA structures at these length scales, and additionally a platform for future studies exchanging the materials or altering the ligation scheme.

CdS