Browse Topic: Spectroscopy
In physical chemistry, time-resolved spectroscopy is the study of dynamic processes in materials or chemical compounds. Within this field, various techniques including transient absorption spectroscopy are used to study the mechanistic and kinetic details of chemical processes that occur within just a few picoseconds to a femtosecond — the equivalent of one millionth of one billionth of a second.
Have you ever gazed at the vastness of the stars and wondered what else your CNC machine can create? Greg Green had the opportunity to find out when he joined the staff at the Canada-France-Hawaii Telescope (CFHT) in Waimea, Hawaii.
Light measurement devices called optical frequency combs have revolutionized metrology, spectroscopy, atomic clocks, and other applications. Yet challenges with developing frequency comb generators at a microchip scale have limited their use in everyday technologies such as handheld electronics.
Lasers developed at the University of Rochester offer a new path for on-chip frequency comb generators. University of Rochester, Rochester, NY Light measurement devices called optical frequency combs have revolutionized metrology, spectroscopy, atomic clocks, and other applications. Yet challenges with developing frequency comb generators at a microchip scale have limited their use in everyday technologies such as handheld electronics. In a study published in Nature Communications, researchers at the University of Rochester describe new microcomb lasers they have developed that overcome previous limitations and feature a simple design that could open the door to a broad range of uses.
A Columbia Engineering team has published a paper in the journal Joule that details how nuclear magnetic resonance spectroscopy techniques can be leveraged to design the anode surface in lithium metal batteries. The researchers also present new data and interpretations for how this method can be used to gain unique insight into the structure of these surfaces.
MIT Cambridge, MA
Optical parametric oscillator (OPO) lasers test optical fibers and components to characterize the spectral response of optical components. OPO lasers are common in sophisticated test and measurement applications such as mass spectrometry, photoacoustic imaging, and spectroscopy. Now, these tunable pulsed lasers are being used to facilitate a range of tests at different wavelengths to qualify and quantify the performance of optical components such as fiber optic strands, filters, lenses, and coated mirrors.
Multicolored light-emitting arrays could be useful in low-power sensing, computing, and spectroscopy, but too often their spectral range is limited to a few colors due to material and device constraints. Now, Berkeley engineers have devised a way to produce an economical and compact light-emitting device with limitless colors that could greatly increase resolution in spectral imaging.
Mass spectrometry (MS), which is used to identify molecules within a sample by measuring the mass-to-charge ratio of ions, is employed across many fields of study, including biology, chemistry, physics, and clinical medicine. As the technology continues to evolve, so will the applications that can benefit from this important tool.
Chemical Vapor Deposition (CVD) and Atomic Layer Deposition (ALD) processes deposit material on all surfaces in a process chamber. Over time, the thickness of these deposits increases to the point that material begins to delaminate, producing gas-phase particulates that negatively impact process yield. Remote and in situ chemical etching processes are used to periodically remove these deposits from chamber walls, maintaining chamber cleanliness.
A threat in the form of chemical vapor may not be visible, but rapid detection is critical for preservation of life and property. In addition, understanding the surrounding environment informs the posture that the warfighter will need to take. The field of chemical vapor detection spans far beyond the warfighter and is rich in research. A search in SciFinder for “chemical vapor detection” provides over 400,000 results with over 3,000 books, 26,000 reviews, and nearly 300,000 journal articles. The focus of this document will be with an eye towards perimeter monitoring for a wide range of gas-phase chemicals. To accomplish such sensing, compound-specific sensors should not be employed as they lack capability to detect or inform about the presence of many potential threats outside of their selected targets. A viable technique for sensing a wide range of compounds is infrared absorption as most potential threats provide an infrared absorbance spectrum which arises from each compound’s unique molecular structure.
A presentation of work comparing efficacy of a traditional IR method used as a standard within the U.S. Army Combat Capabilities Development Command (DEVCOM) and by international collaborators with that of an emerging technology, cavity ring down spectroscopy (CRDS). Army Combat Capabilities Development Command, Aberdeen Proving Ground, MD A threat in the form of chemical vapor may not be visible, but rapid detection is critical for preservation of life and property. In addition, understanding the surrounding environment informs the posture that the warfighter will need to take. The field of chemical vapor detection spans far beyond the warfighter and is rich in research. A search in SciFinder for “chemical vapor detection” provides over 400,000 results with over 3,000 books, 26,000 reviews, and nearly 300,000 journal articles. The focus of this document will be with an eye towards perimeter monitoring for a wide range of gas-phase chemicals. To accomplish such sensing, compound-specific sensors should not be employed as they lack capability to detect or inform about the presence of many potential threats outside of their selected targets. A viable technique for sensing a wide range of compounds is infrared absorption as most potential threats provide an infrared absorbance spectrum which arises from each compound's unique molecular structure. The purpose of this article is to provide a comparison between a commercially available instrument long utilized as a standard within several defense laboratories around the globe which employs FTIR methods for detection of environmental gasses in industrial environments to a newer class of IR absorption-based detectors that use cavity ringdown to determine the absorption profile.
As NASA expands its quest to discover exoplanets — planets beyond our solar system — it also grows its toolbox. Last summer, a new tool called NEID (pronounced NOO-id) delivered its first batch of data on the nearest and best-studied star, our Sun.
Army Research Laboratory, Adelphi, MD Developing single photon UV detection for compact chemical and biological sensors. This report summarizes the main lines of effort for the Electro-Optics Materials Research (EOMR) program including its goals and major accomplishments, focusing on the past 5 years. This EOMR program was an effort within 601102A.31B.1 titled “Optoelectronic and Integrated Photonic Materials and Device Research” for FY16-FY19 and 611102A.AA8.1 titled “Photonic Materials and Device Research” for FY20-FY21. The focus of this EOMR for most of the program was to develop novel semiconductor optoelectronic devices to reduce the size, weight, power, and cost (SWaP-C) of chemical and biological detection and identification systems. Specifically, the program addressed the need for high sensitivity photodetectors in the near-UV (NUV) spectrum between 300 and 350 nm for biological agent detection using light-induced fluorescence techniques employed by the Tactical Biological (TAC-BIO) detector, developed by the US Army Combat Capabilities Development Command Chemical Biological Center, as well as in the deep UV spectrum (220-240 nm) important for standoff chemical detection based upon fluorescence-free Raman spectroscopy. Late in the program, this effort pivoted to address assured communications challenges relevant to the Army modernization priority for future networks through examining how to improve the efficiency of solar-blind UV LEDs.
Mobile NIR spectroscopy has gathered a lot of interest in recent years. On site and real time measurements of the chemical composition of solid or fluid samples could be applied to identification, authentication or estimation of quality parameters and similar relevant measurement tasks. This measurement technique is particularly useful for, but not limited to samples containing organic compounds.
Scientists, including an Oregon State University materials researcher, have developed a better tool to measure light, contributing to a field known as optical spectrometry in a way that could improve everything from smartphone cameras to environmental monitoring.
This article discusses the basic design concepts of a UV-visible-NIR range microscope spectrometer in several different configurations. These include configurations to acquire absorbance, reflectance, fluorescence and Raman spectra of microscopic samples. A brief summary of some of the uses of the microscope-spectrometer is also included.
Developed by Rudolph Diesel in the 1890s, the diesel powertrain is used in many applications worldwide. For significant time the engine fuel source for these engines was petroleum diesel, until new legislation regarding emission reduction and smog mitigation saw the introduction of petroleum diesel and biodiesel (Fatty acid methyl ester; FAME) blends in the early 2000s. Since then there have been many instances of filters in diesel powertrains across heavy, light and off-road platforms becoming blocked with unidentified material, for example in the United States, Northern Europe and Scandinavia. Filters are designed to remove contaminants from the fuel system and as the filter becomes plugged it restricts the fuel flow resulting in loss of engine power and eventual breakdown. Understanding The nature of the material responsible for such blockages is clearly important to the industry and has been the subject of many studies. However, it is also clear from such work that not all the materials responsible for filter blocking have been identified. This work will describe the application of a variety of mass spectrometry techniques such as Fourier Transforms Ion Cyclotron Mass Spectrometry (FT-ICR-MS); Ultrahigh Performance Supercritical Fluid Mass Spectrometry. (UHPSFC-MS) to further identify the filter blocking materials in conjunction with more traditional analytical techniques for example Scanning Electron Microscopy, (SEM), X-ray Fluorescence Spectroscopy (EDS) and Fourier Transform Infra-red Microscopy (FTIRM).
Scientists used photoelectrochemical measurement and x-ray photoelectron spectroscopy to clarify the source of titanium’s biocompatibility when implanted into the body, as with hip replacements and dental implants. They find that its reactivity with the correct ions in the extracellular fluid allows the body to recognize it. This work may lead to a new generation of medical implants that last longer.
To define capabilities and limitations of Raman spectroscopy as it pertains to counterfeit detection of EEE parts and suggest possible applications to these ends. Additionally, this document outlines requirements associated with the application of Raman spectroscopy including: Operator training; Sample preparation; Data interpretation; Computerized spectral matching including pass/fail criteria; Equipment maintenance and; Reporting of data. If AS6171/8 is invoked in the contract, the base document, AS6171 General Requirements shall also apply.
This document defines capabilities and limitations of FTIR spectroscopy as it pertains to counterfeit electronic component detection and suggests possible applications to these ends. Additionally, this document outlines requirements associated with the application of FTIR spectroscopy including: operator training, sample preparation, various sampling techniques, data interpretation, computerized spectral matching including pass/fail criteria, equipment maintenance, and reporting of data. The discussion is primarily aimed at analyses performed in the mid-infrared (IR) from 400 to 4000 wavenumbers; however, many of the concepts are applicable to the near and far IR. If AS6171/9 is invoked in the contract, the base document, AS6171 General Requirements shall also apply.
Titan, Saturn’s largest moon and the only celestial body which is found to have a landmass composed of liquid hydrocarbons. Nitrogen - The building block of all life that exists on earth is found to be abundant in Titan’s atmosphere of up to 97%. Aerobots provide a great platform for exploring a celestial body with an atmosphere such as Titan. They have modest power requirements, longer mission duration, and can cover a longer distance in a shorter time. They are powered by a Radioisotope Thermoelectric Generator for optimal mission life. Aerobot’s altitude can be altered by varying the temperature of the air inside the balloon and yaw can be controlled using a Reaction Wheel and a motor-driven propeller for forwarding thrust. The proposed Aerobot will be equipped with four miniature deployable fixed weather stations that can be dropped from the aerobot to Titan's surface. They can be deployed at diverse locations such as the equator and Polar Regions to deeply explore the Titan’s climate and atmosphere. These weather stations contain payloads such as nitrogen, methane, oxygen sensor, and a spectrometer to analyze the composition of the atmosphere. Temperature sensors and wind speed sensors can be equipped. Also, a lightning detector can be used to trace lightning and thunderstorm, an essential element for organisms’ inhabitable environments. Radiation sensors both in weather stations and Aerobots can help us to understand the risks in its atmosphere. These weather stations are mounted on a floatable structure to float on rivers on Titan. They have an on-board memory storage facility to store data from sensors and transmit the saved data once the aerobot comes across them in the sky. Also, the aerobot will be inflated before landing on Titan to safeguard the aerobot without falling on to rivers of Titan. This work focused to design and computationally investigates the fluid dynamic behaviour and its structural impacts on the proposed Unmanned Aerobot under the environmental conditions of Titan.
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