Tech Briefs

A comprehensive library of technical briefs from engineering experts at NASA and major government, university, and commercial laboratories covering all aspects of innovations in electronics, software, photonics, imaging, motion control, automation, sensors, test, materials, manufacturing, mechanical, and mechatronics.

Briefs : Information Technology
Improved Model of a Mercury Ring Damper

A short document discusses the general problem of mathematical modeling of the three-dimensional rotational dynamics of rigid bodies and of the use of Euler parameters to eliminate the singularities occasioned by the use of Euler angles in such modeling. The document goes on to characterize a Hamiltonian...

Briefs : Medical
Optoelectronic pH Meter: Further Details

A collection of documents provides further detailed information about an optoelectronic instrument that measures the pH of an aqueous cell-culture medium to within ±0.1 unit in the range from 6.5 to 7.5. The instrument at an earlier stage of development was reported in “Optoelectronic Instrument...

Briefs : Mechanical & Fluid Systems
X-38 Advanced Sublimator

A document discusses a heat rejection device for transferring heat from a space vehicle by venting water into space through the use of a novel, two-stage water distribution system. The system consists of two different, porous media that stop water-borne contaminants from clogging the system and causing operational...

Briefs : Physical Sciences
Solar Simulator Represents the Mars Surface Solar Environment

A report discusses the development of a Mars surface, laboratory-based solar simulator to create solar cells that can function better on Mars. The Mars Optimized Solar cell Technology (MOST) required defining the surface incident spectrum, developing an appropriate laboratory solar...

Briefs : Medical
Magnetic Plungerless Injection System

The Magnetic Plungerless Injection System (MPIS) was invented to enhance the therapeutic value and market availability of parenterally delivered pharmaceuticals and vaccines. The MPIS is a mechanical arrangement of a proprietary single-dosage cartridge and a magnetic actuator, and is a combination of the...

Briefs : Medical
Exact Dose Dispensing Closure for Semi-Solids

A novel closure technology now makes it possible to consistently squeeze an exact dose of semi-solids from a tube by means of a 180-degree rotating closure. It has potential uses in pharmaceutical transdermal and oral applications, as well as glue dispensing, semi-solid food dispensing, and paint...

Briefs : Medical
Graphite Non-Wovens as Functional Layers in Diagnostic Test Kits

The separation of serum or plasma from whole blood is of overriding importance in clinical chemistry. In particular, many diagnostic detection reactions of blood components proceed without impairment only after the red blood corpuscles have been separated off. This particularly...

Briefs : Medical
Modular Electronic Air Sterilization Technology

Ultraviolet germicidal irradiation (UVGI) technologies are being used as infection control devices, primarily in healthcare facilities. No standard exists, but the dose of UV and the airflow are critical to ensuring all contaminated air is treated. The UVGI process is mainly influenced by the...

Briefs : Medical
Quantifying Therapeutic and Diagnostic Efficacy in 2D Microvascular Images

VESGEN is a newly automated, userinteractive program that maps and quantifies the effects of vascular therapeutics and regulators on microvascular form and function. VESGEN analyzes two-dimensional, black and white vascular images by measuring important vessel morphology...

Briefs : Medical
Microwave Sterilization and Depyrogenation System

A fully functional, microgravity-compatible microwave sterilization and depyrogenation system (MSDS) prototype was developed that is capable of producing medical-grade water (MGW) without expendable supplies, using NASA potable water that currently is available aboard the International Space...

Briefs : Medical
Reliability and Validity of a Prototype Fluid Intake Monitor

Maintaining adequate hydration is an important part of maintaining health, especially under extreme operational and environmental conditions where medical assistance might not be readily available. One approach to measuring the amount of fluid consumed is through the use of Fluid...

Briefs : Medical
A Finite-Element Model for Evaluation of Middle Ear Mechanics

In conductive hearing loss cases, 59% involve defects of the incus. For efficient restoration of hearing, the defective incus is normally removed and the mechanical link between the eardrum and inner ear is reconstructed. In cases of incus defects, the reconstruction is normally of...

Briefs : Physical Sciences
Solar Rejection Filter for Large Telescopes

To reject solar radiation photons at the front aperture for large telescopes, a mosaic of large transmission mode filters is placed in front of the telescope or at the aperture of the dome. Filtering options for effective rejection of sunlight include a smaller filter down-path near the focus of the...

Briefs : Electronics & Computers
Free-Space Optical Interconnect Employing VCSEL Diodes

Sensor signal processing is widely used on aircraft and spacecraft. The scheme employs multiple input/output nodes for data acquisition and CPU (central processing unit) nodes for data processing. To connect 110 nodes and CPU nodes, scalable interconnections such as backplanes are desired...

Briefs : Physical Sciences
Critical Coupling Between Optical Fibers and WGM Resonators

Two recipes for ensuring critical coupling between a single-mode optical fiber and a whispering-gallery-mode (WGM) optical resonator have been devised. The recipes provide for phase matching and aperture matching, both of which are necessary for efficient coupling. There is also a...

Briefs : Energy
Lattice-Matched Semiconductor Layers on Single Crystalline Sapphire Substrate
SiGe is an important semiconductor alloy for high-speed field effect transistors (FETs), high-temperature thermoelectric devices, photovoltaic solar cells, and photon detectors. The growth of SiGe layer is difficult because SiGe alloys have different lattice constants...
Briefs : Information Technology
Progressive Classification Using Support Vector Machines

An algorithm for progressive classification of data, analogous to progressive rendering of images, makes it possible to compromise between speed and accuracy. This algorithm uses support vector machines (SVMs) to classify data. An SVM is a machine learning algorithm that builds a...

Briefs : Information Technology
Active Learning With Irrelevant Examples

An improved active learning method has been devised for training data classifiers. One example of a data classifier is the algorithm used by the United States Postal Service since the 1960s to recognize scans of handwritten digits for processing zip codes. Active learning algorithms enable rapid training...

Briefs : Photonics/Optics
Solar Rejection Filter for Large Telescopes

To reject solar radiation photons at the front aperture for large telescopes, a mosaic of large transmission mode filters is placed in front of the telescope or at the aperture of the dome. Filtering options for effective rejection of sunlight include a smaller filter down-path near the focus of the...

Briefs : Photonics/Optics
Free-Space Optical Interconnect Employing VCSEL Diodes

Sensor signal processing is widely used on aircraft and spacecraft. The scheme employs multiple input/output nodes for data acquisition and CPU (central processing unit) nodes for data processing. To connect 110 nodes and CPU nodes, scalable interconnections such as backplanes are desired...

Briefs : Photonics/Optics
Critical Coupling Between Optical Fibers and WGM Resonators

Two recipes for ensuring critical coupling between a single-mode optical fiber and a whispering-gallery-mode (WGM) optical resonator have been devised. The recipes provide for phase matching and aperture matching, both of which are necessary for efficient coupling. There is also a...

Briefs : Mechanical & Fluid Systems
Light-Driven Polymeric Bimorph Actuators

Light-driven polymeric bimorph actuators are being developed as alternatives to prior electrically and optically driven actuators in advanced, highly miniaturized devices and systems exemplified by micro-electromechanical systems (MEMS), micro-electro-optical-mechanical systems (MEOMS), and sensor and...

Briefs : Information Technology
Guaranteeing Failsafe Operation of Extended-Scene Shack-Hartmann Wavefront Sensor Algorithm

A Shack-Hartmann sensor (SHS) is an optical instrument consisting of a lenslet array and a camera. It is widely used for wavefront sensing in optical testing and astronomical adaptive optics. The camera is placed at the focal point of the lenslet array...

Briefs : Mechanical & Fluid Systems
T-Slide Linear Actuators

T-slide linear actuators use gear bearing differential epicyclical transmissions (GBDETs) to directly drive a linear rack, which, in turn, performs the actuation. Conventional systems use a rotary power source in conjunction with a nut and screw to provide linear motion. Non-back-drive properties of GBDET’s make the...

Briefs : Physical Sciences
Cloud Water Content Sensor for Sounding Balloons and Small UAVs

A lightweight, battery-powered sensor was developed for measuring cloud water content, which is the amount of liquid or solid water present in a cloud, generally expressed as grams of water per cubic meter. This sensor has near-zero power consumption and can be flown on standard...

Briefs : Physical Sciences
Pixelized Device Control Actuators for Large Adaptive Optics

A fully integrated, compact, adaptive space optic mirror assembly has been developed, incorporating new advances in ultralight, high- performance composite mirrors. The composite mirrors use Q-switch matrix architecture- based pixelized control (PMN-PT) actuators, which achieve high-...

Briefs : Semiconductors & ICs
Low-Noise MMIC Amplifiers for 120 to 180 GHz

Three-stage monolithic millimeter-wave integrated-circuit (MMIC) amplifiers capable of providing useful amounts of gain over the frequency range from 120 to 180 GHz have been developed as prototype low-noise amplifiers (LNAs) to be incorporated into instruments for sensing cosmic microwave background...

Briefs : Semiconductors & ICs
Three MMIC Amplifiers for the 120-to-200 GHz Frequency Band

Closely following the development reported in the article, "Low-Noise MMIC Amplifiers for 120 to 180 GHz" (NPO-42783), three new monolithic microwave integrated circuit (MMIC) amplifiers that would operate in the 120-to-200- GHz frequency band have been designed and are under...

Briefs : Electronics & Computers
G⁴FET Implementations of Some Logic Circuits

Some logic circuits have been built and demonstrated to work substantially as intended, all as part of a continuing effort to exploit the high degrees of design flexibility and functionality of the electronic devices known as G4FETs and described below. These logic circuits are intended...

Briefs : Electronics & Computers
Complementary Paired G⁴FETs as Voltage-Controlled NDR Device

It is possible to synthesize a voltage-controlled negative-differential-resistance (NDR) device or circuit by use of a pair of complementary G4FETs (four-gate field-effect transistors). [For more information about G4FETs, please see "G4FET...

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