Matthew Staymates’s picture

By: Matthew Staymates

As a fluid dynamicist and mechanical engineer at the National Institute of Standards and Technology (NIST), I’ve devoted much of my career to helping others see things that are often difficult to detect. I’ve shown the complex flow of air that occurs when a dog sniffs. I’ve helped develop ways to detect drugs and explosives by heating them into a vapor. I’ve explored how drug residue can contaminate crime labs. I’ve even shown how to screen shoes for explosives.

Most of these examples fit into a common theme: detecting drugs and explosives through the flow of fluids that are usually invisible. When I’m in the laboratory, I use a number of advanced fluid flow-visualization tools to help better understand and improve our ability to detect illicit drugs and explosives on surfaces, on people, and in the environment.

NIST’s picture

By: NIST

Researchers at the National Institute of Standards and Technology (NIST) have used state-of-the-art atomic clocks, advanced light detectors, and a measurement tool called a frequency comb to boost the stability of microwave signals a hundredfold. This marks a giant step toward better electronics to enable more accurate time dissemination, improved navigation, more reliable communications, and higher-resolution imaging for radar and astronomy. Improving the microwave signal’s consistency over a specific time period helps ensure reliable operation of a device or system.

The work transfers the already superb stability of the cutting-edge laboratory atomic clocks operating at optical frequencies to microwave frequencies, which are currently used to calibrate electronics. Electronic systems are unable to directly count optical signals, so the NIST technology and techniques indirectly transfer the signal stability of optical clocks to the microwave domain. The demonstration is described in the May 22, 2020, issue of Science.

Multiple Authors
By: John Smits, Gary Confalone, Tom Kinnare

Confusion between the two terms “RADAR” and “LIDAR” is understandable. Their names are nearly synonymous, and the terms are often used interchangeably. The acronyms are RADAR, which stands for RAdio Detection And Ranging; and LIDAR, which stands for LIght Detection And Ranging. The major difference between the two is the wavelength of the signal and the divergence of the signal beam.

LIDAR is typically a collimated light beam with minimal divergence over long distances from the transmitter; RADAR is a cone-shaped signal fanning out from the source. Both calculate distance by comparing the time it takes for the outgoing wave or pulse to return to the source. LIDAR uses light wave frequencies that have a shorter wavelength, which enhances the capability of collecting data with high precision. RADAR uses longer microwave frequencies, which have lower resolution but the ability to collect signals with reduced impact from environmental obstructions. RADAR and LIDAR signals both travel at the speed of light.

Quality Digest’s picture

By: Quality Digest

It’s easy to assume that something as simple as a mask wouldn’t pose much of a risk. Essentially, it’s just a covering that goes over your nose and mouth.

But masks are more than just stitched-together cloth. Medical-grade masks use multiple layers of nonwoven material, usually polypropylene, designed to meet specific standards for how big and how many particles they can block. And they are tested and certified to determine how well they do that job.

Healthcare and other frontline workers usually use either a surgical mask or an N95 mask. Both protect the patient from the wearer’s respiratory emissions. But where surgical masks provide the wearer protection against large droplets, splashes, or sprays of bodily or other hazardous fluids, an N95 mask is designed to achieve a very close facial fit and very efficient filtration of submicron airborne particles.

The “N95” (or “KN95”) designation means that the respirator blocks at least 95 percent of very small (0.3 micron) test particles. If properly fitted, the filtration capabilities of N95 respirators exceed those of face masks.

NIST’s picture

By: NIST

Scientists at the National Institute of Standards and Technology (NIST) have devised a novel, accurate, easy-to-operate, time- and labor-saving way to provide calibrated scale-bar standards for testing the performance of terrestrial laser scanner (TLS) systems.

TLS technology is widely employed to create detailed, high-resolution, 3D digital images of terrain, buildings, vegetation, construction projects, crime-scene forensics and—increasingly—very large objects such as airframe components that must be fitted together with precision, often on the scale of a few hundred micrometers (millionths of a meter; a human hair is about 100 micrometers thick).

“Of course, for geodesy and surveying and most forensic uses, you don’t really need micrometer resolution,” says NIST project scientist Vincent Lee. “But TLS systems are now often used in aerospace and ship building, where big components have to be joined very meticulously, like a wing onto a fuselage. That’s where measurements from a few hundred micrometers to a millimeter really matter.” And that’s where careful system testing really matters. (See video three below.)

Gleb Tsipursky’s picture

By: Gleb Tsipursky

So many companies are shifting their employees to working from home to address the Covid-19 coronavirus pandemic. Yet they’re not considering the potential quality disasters that can occur as a result of this transition.

An example of this is what one of my coaching clients experienced more than a year before the pandemic hit. Myron is the risk and quality management executive in a medical services company with about 600 employees. He was one of the leaders tasked by his company’s senior management team with shifting the company’s employees to a work-from-home setup, due to rising rents on their office building.

Specifically, Myron led the team that managed risk and quality issues associated with the transition for all 600 employees to telework, due to his previous experience in helping small teams of three to six people in the company transition to working from home in the past. The much larger number of people who had many more diverse roles they had to assist now was proving to be a challenge. So was the short amount of time available to this project, which was only four weeks, and resulted from a failure in negotiation with the landlord of the office building.

David H. Parker’s picture

By: David H. Parker

It is well known that the speed of light depends on the index of refraction of the medium in which the light is propagating. It is also well known that in a dispersive medium, the speed of an amplitude modulated wavefront depends on the group refractive index, i.e., slightly slower than the carrier light. Corrections for the group refractive index in air are typically made for temperature, humidity, and pressure—without which measurements could be in error by tens of parts per million. The internal instrument optical elements are also subject to dispersive effects, which have heretofore been ignored in the literature—and presumably in the design. Note that this is probably because no commercially available optical design software package models amplitude modulated wavefronts. A thought experiment will illustrate the problem.

Greg Hoeting’s picture

By: Greg Hoeting

Nuclear power has long been a clean, dependable source of energy throughout the world. However, as power plants age, concerns grow about their continued reliability. Many components make up the infrastructure of a nuclear power plant with the design intent to reduce radiation and contamination exposure to personnel, equipment, and the surrounding environment.

One of the biggest sources of this radiation and contamination comes from the vast network of pipes throughout the plant.

Olympus America’s picture

By: Olympus America

F unction often relates to form, and this is particularly true within the world of manufacturing. Rigorous quality assessment procedures ensure that components are manufactured according to their precise specifications before being assembled into the fully functioning whole. These assessments might include tasks such as geometric product specifications, fracture analysis, and surface roughness testing, and they form the core of quality control in many manufacturing processes. As such, identical tasks may be performed across industrial sectors as diverse as medical engineering, electronics, and the automotive industry. This article explores the limitations of existing approaches to quality assessment within industry, and details how opto-digital technology can be used as a more efficient alternative.

Techniques commonly used to accomplish tasks in quality assessment include contact profilometry and traditional light microscopy, and these demand a high level of accuracy in both inspection and metrology. Although these successful approaches are heavily relied on within industrial quality assessment, the novel approach of opto-digital microscopy is becoming an increasingly popular solution, bringing industrial quality control into the digital era.

Multiple Authors
By: Donald J. Wheeler, Al Pfadt

Each day we receive data that seek to quantify the Covid-19 pandemic. These daily values tell us how things have changed from yesterday, and give us the current totals, but they are difficult to understand simply because they are only a small piece of the puzzle. And like pieces of a puzzle, data only begin to make sense when they are placed in context. And the best way to place data in context is with an appropriate graph.

When using epidemiological models to evaluate different scenarios it is common to see graphs that portray the number of new cases, or the demand for services, each day.1 Typically, these graphs look something like the curves in figure 1.


Figure 1: Epidemiological models produce curves of new cases under different scenarios in order to compare peak demands over time. (Click image for larger view.)

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