Special Coverage

Lightweight, Flexible Thermal Protection System for Fire Protection
High-Precision Electric Gate for Time-of-Flight Ion Mass Spectrometers
Polyimide Wire Insulation Repair System
Distributed Propulsion Concepts and Superparamagnetic Energy Harvesting Hummingbird Engine
Aerofoam
Wet Active Chevron Nozzle for Controllable Jet Noise Reduction
Magnetic Relief Valve
Active Aircraft Pylon Noise Control System
Unmanned Aerial Systems Traffic Management
Home

Optical Measurement of Mass Flow of a Two-Phase Fluid

Density and mass flow are estimated from wavelength-dependent scattering of light. An optoelectronic system utilizes wavelength-dependent scattering of light for measuring the density and mass flow of a two-phase fluid in a pipe. The apparatus was invented for original use in measuring the mass flow of a twophase cryogenic fluid (e.g., liquid hydrogen containing bubbles of hydrogen gas), but underlying principles of operation can readily be adapted to non-cryogenic two-phase fluids.

Posted in: Briefs, Physical Sciences

Read More >>

Piezoelectric Bolt Breakers and Bolt Fatigue Testers

Safer alternative to spacecraft explosive bolts may accelerate fatigue testing on Earth. A proposed family of devices for inducing fatigue in bolts in order to break the bolts would incorporate piezoelectric actuators into resonant fixtures as in ultrasonic/ sonic drills/corers and similar devices described in numerous prior NASA Tech Briefs articles. These devices were originally intended primarily for use as safer, more-reliable, more-versatile alternatives to explosive bolts heretofore used to fasten spacecraft structures that must subsequently be separated from each other quickly on command during flight. On Earth, these devices could be used for accelerated fatigue testing of bolts.

Posted in: Briefs, TSP, Mechanical Components, Mechanics

Read More >>

Improved Measurement of B22 of Macromolecules in a Flow Cell

Invention helps researchers understand conditions that affect protein crystallization. An improved apparatus has been invented for use in determining the osmotic second virial coefficient of macromolecules in solution. In a typical intended application, the macromolecules would be, more specifically, protein molecules, and the protein solution would be pumped through a flow cell to investigate the physical and chemical conditions that affect crystallization of the protein in question.

Posted in: Briefs, Bio-Medical, Medical

Read More >>

Measurements by a Vector Network Analyzer at 325 to 508 GHz

Recent experiments were performed in which return loss and insertion loss of waveguide test assemblies in the frequency range from 325 to 508 GHz were measured by use of a swept-frequency two-port vector network analyzer (VNA) test set. The experiments were part of a continuing effort to develop means of characterizing passive and active electronic components and systems operating at ever increasing frequencies. The waveguide test assemblies comprised WR-2.2 end sections collinear with WR-3.3 middle sections. The test set, assembled from commercially available components, included a 50-GHz VNA scatteringparameter test set and external signal synthesizers, augmented with recently developed frequency extenders, and further augmented with attenuators and amplifiers as needed to adjust radio-frequency and intermediate- frequency power levels between the aforementioned components.

Posted in: Briefs, Electronics & Computers

Read More >>

Selectable-Tip Corrosion-Testing Electrochemical Cell

The diameter and average depth of a corrosion pit can be selected. The figure depicts aspects of an electrochemical cell for pitting-corrosion tests of material specimens. The cell is designed to generate a region of corrosion having a pit diameter determined by the diameter of a selectable tip. The average depth of corrosion is controlled by controlling the total electric charge passing through the cell in a test. The cell is also designed to produce minimal artifacts associated with crevice corrosion.

Posted in: Briefs, Physical Sciences

Read More >>

Using Light To Treat Mucositis and Help Wounds Heal

Arrays of LEDs would generate biostimulatory radiation. A continuing program of research and development is focusing on the use of controlled illumination by light-emitting diodes (LEDs) to treat mucositis and to accelerate healing of wounds. The basic idea is to illuminate the affected area of a patient with light of an intensity, duration, and wavelength (or combination of wavelengths) chosen to produce a therapeutic effect while generating only a minimal amount of heat.

Posted in: Briefs, Bio-Medical, Medical

Read More >>

Error-Detecting Counters for FPGA and ASIC State Machines

Inconsistencies between main and auxiliary counts would be detected. Error-detecting counters have been proposed as parts of fault-tolerant finite state machines that could be implemented in field-programmable gate arrays (FPGAs) and application-specific integrated circuits that perform sequential logic functions. The use of error-detecting counters would complement the fault-tolerant coding schemes described in “Fault-Tolerant Coding for State Machines” (NPO-41050), in this issue on page 55. Counters are often used in state machines in cases in which it is necessary to represent large numbers of states and/or to count clock cycles between certain states. To ensure reliability, it is necessary to ensure that the counters are as free of faults as are the other parts of the state machines.

Posted in: Briefs, TSP, Semiconductors & ICs

Read More >>

The U.S. Government does not endorse any commercial product, process, or activity identified on this web site.