(Press-News.org) Laser-induced breakdown spectroscopy (LIBS) is a rapid chemical analysis tool. A powerful laser pulse is focused on a sample to create a microplasma. The elemental or molecular emission spectra from that microplasma can be used to determine the elemental composition of the sample.
Compared with more traditional technology, like atomic absorption spectroscopy and inductively coupled plasma optical emission spectroscopy (ICP-OES), LIBS has some unique advantages: no sample pretreatment, simultaneous multi-element detection, and real-time noncontact measurements. These advantages make it suitable for practical analysis of solids, gases, and liquids.
Traditional LIBS and extensions
Traditional LIBS systems based on a nanosecond pulse laser (ns-LIBS) have some disadvantages due to laser power intensity, long pulse duration, and the plasma shielding effect. These issues adversely affect its reproducibility and signal-to-noise ratio. Femtosecond LIBS (fs-LIBS) can exclude the plasma shielding effect since the ultrashort pulse duration limits the laser-matter interaction time. The femtosecond pulse has a high power density so materials can be effectively ionized and dissociated, leading to a higher signal-to-background ratio and more precise spectral resolution.
Filament-induced breakdown spectroscopy (FIBS) combines the LIBS technique with a femtosecond laser filament. A single laser filament results from the interplay between the Kerr self-focusing and plasma defocusing mechanisms present in the propagation of an ultrashort, high-intensity beam in a transparent medium such as atmospheric air. The femtosecond laser filament produces a long and stable laser plasma channel, which guarantees the stability of the laser power density and can improve measurement stability. However, the power and electron densities saturate when the laser energy increases. This is known as laser intensity clamping effect, and it limits the detection sensitivity of FIBS.
Plasma grating
Fortunately, the laser intensity clamping effect can be overcome through a plasma grating induced by the nonlinear interaction of multiple femtosecond filaments. The electron density in the plasma grating has been proven to be an order of magnitude higher than that in a filament.
Based on that insight, researchers under the leadership of Heping Zeng at East China Normal University in Shanghai END
Breakthrough for laser-induced breakdown spectroscopy
Overcoming limitations inherent in other LIBS techniques, plasma-grating-induced breakdown spectroscopy enhances signal intensity by more than three times
2021-01-28
[Attachments] See images for this press release:
ELSE PRESS RELEASES FROM THIS DATE:
Harnessing the power of AI to understand warm dense matter
2021-01-28
The study of warm dense matter helps us understand what is going on inside giant planets, brown dwarfs, and neutron stars. However, this state of matter, which exhibits properties of both solids and plasmas, does not occur naturally on Earth. It can be produced artificially in the lab using large X-ray experiments, albeit only at a small scale and for short periods of time. Theoretical and numerical models are essential to evaluate these experiments, which are impossible to interpret without formulas, algorithms, and simulations. Scientists at the Center for Advanced Systems Understanding (CASUS) at the Helmholtz-Zentrum Dresden-Rossendorf (HZDR) have now developed a method to evaluate such ...
National laboratories' look to the future of light sources with new magnet prototype
2021-01-28
With a powerful enough light, you can see things that people once thought would be impossible. Large-scale light source facilities generate that powerful light, and scientists use it to create more durable materials, build more efficient batteries and computers, and learn more about the natural world.
When it comes to building these massive facilities, space is money. If you can get higher-energy beams of light out of smaller devices, you can save millions on construction costs. Add to that the chance to significantly improve the capabilities of existing light sources, and you have the motivation behind a project that has brought scientists at three U.S. Department of Energy national laboratories together.
This team has just achieved an important milestone ...
Genetic analysis of symptoms yields new insights into PTSD
2021-01-28
Attempts to identify the genetic causes of neuropsychiatric diseases such as post-traumatic stress disorder (PTSD) through large-scale genome-wide analyses have yielded thousands of potential links. The challenge is further complicated by the wide range of symptoms exhibited by those who have PTSD. For instance, does extreme arousal, anger, or irritation experienced by some have the same genetic basis as the tendency to re-experience traumatic events, another symptom of the disorder?
A new study led by researchers at Yale and the University of California-San Diego (UCSD) provides answers to some of these questions and uncovers intriguing genetic similarities between PTSD and other mental health disorders such as anxiety, bipolar disorder, and schizophrenia. ...
At-home swabs diagnose infections as accurately as healthcare worker-collected swabs
2021-01-28
Washington, DC - January 28, 2021 - Self swabs and caregiver swabs are effective at detecting multiple pathogens and are just as accurate as those taken by healthcare workers, according to a team of Australian researchers. The research appears in the Journal of Clinical Microbiology, a publication of the American Society for Microbiology.
"Across the range of pathogens and swab types, there was high agreement between results from self- or caregiver swabs and those performed by a healthcare worker, even when different sites were swabbed (e.g. nasopharyngeal vs. nasal)," said principal investigator Joshua Osowicki, BMedSci, MBBS, FRACP, a Pediatric Infectious Diseases physician in the Murdoch Children's Research Institute's ...
Modeling study of ancient thumbs traces the history of hominin thumb dexterity
2021-01-28
Despite long-standing ideas about the importance of thumb evolution in tool use and development, questions remain about exactly when human-like manual dexterity and efficient thumb use arose--and which hominin species was the first to have this ability. Now, researchers who've analyzed the biomechanics and efficiency of the thumb across different fossil human species using virtual muscle modeling have new insight into when these abilities first arose and what they've meant for the development of more complex human culture. The findings, appearing January 28 in the journal Current Biology, suggest that a fundamental aspect of human thumb opposition first appeared approximately 2 million years ago and was not found ...
Risk-taking behavior has a signature in the brain, big data shows
2021-01-28
What makes one person drive above the speed limit while another navigates steadily in the right lane? What motivates someone to leave a job with a steady paycheck to launch their own business while the other sticks to one employer for an entire career?
"People have different tendencies to engage in behavior that risks their health or that involve uncertainties about the future," says Gideon Nave, an assistant professor of marketing in Penn's Wharton School.
Yet explaining the origin of those tendencies, both in the genome and in the brain, has been challenging for researchers, partly because previous studies on ...
How a little-known glycoprotein blocks a cancer cell's immune response
2021-01-28
ANN ARBOR, Michigan -- It was an unexpected discovery that started with an analysis of more than 1,000 genes. The question: why game-changing cancer immunotherapy treatments work for only a fraction of patients.
The analysis shone a light on one that popped up repeatedly in patients and mouse models that did not respond to immune checkpoint therapy: stanniocalcin-1, a glycoprotein whose role in both tumors and immunology is largely unknown.
By following the trail from this surprising thread, a University of Michigan Rogel Cancer team uncovered how stanniocalcin-1, or STC1, works inside the cell to block a cellular "eat-me" signal that typically triggers the immune system to produce T cells to fight the tumor. The findings, published in ...
Researchers use patients' cells to test gene therapy for rare eye disease
2021-01-28
Scientists at the National Eye Institute (NEI) have developed a promising gene therapy strategy for a rare disease that causes severe vision loss in childhood. A form of Leber congenital amaurosis, the disease is caused by autosomal-dominant mutations in the CRX gene, which are challenging to treat with gene therapy. The scientists tested their approach using lab-made retinal tissues built from patient cells, called retinal organoids. This approach, which involved adding copies of the normal gene under its native control mechanism, partially restored CRX function. The study report appears today in Stem ...
Using science to explore a 60-year-old Russian mystery
2021-01-28
In early October 2019, when an unknown caller rang EPFL professor Johan Gaume's cell phone, he could hardly have imagined that he was about to confront one of the greatest mysteries in Soviet history. At the other end of the line, a journalist from The New York Times asked for his expert insight into a tragedy that had occurred 60 years earlier in Russia's northern Ural Mountains - one that has since come to be known as the Dyatlov Pass Incident. Gaume, head of EPFL's Snow and Avalanche Simulation Laboratory (SLAB) and visiting fellow at the WSL Institute for Snow and Avalanche Research SLF, had never heard ...
Physicists develop record-breaking source for single photons
2021-01-28
Researchers at the University of Basel and Ruhr University Bochum have developed a source of single photons that can produce billions of these quantum particles per second. With its record-breaking efficiency, the photon source represents a new and powerful building-block for quantum technologies.
Quantum cryptography promises absolutely secure communications. A key component here are strings of single photons. Information can be stored in the quantum states of these light particles and transmitted over long distances. In the future, remote quantum processors will communicate with each other via single photons. And perhaps the processor itself will use photons as quantum bits for computing.
A basic prerequisite for such applications, however, is an efficient source ...
LAST 30 PRESS RELEASES:
Modern AI systems have achieved Turing's vision, but not exactly how he hoped
Quantum walk computing unlocks new potential in quantum science and technology
Construction materials and household items are a part of a long-term carbon sink called the “technosphere”
First demonstration of quantum teleportation over busy Internet cables
Disparities and gaps in breast cancer screening for women ages 40 to 49
US tobacco 21 policies and potential mortality reductions by state
AI-driven approach reveals hidden hazards of chemical mixtures in rivers
Older age linked to increased complications after breast reconstruction
ESA and NASA satellites deliver first joint picture of Greenland Ice Sheet melting
Early detection model for pancreatic necrosis improves patient outcomes
Poor vascular health accelerates brain ageing
Chinese Medical Journal review provides insights into respiratory syncytial virus
Growing safer spuds: removing toxins from potatoes
Russia-Ukraine War’s unexpected casualties: Hungry people in distant nations
York U professor’s new paper challenges tokenizing women of colour in academia
Tiny antennas on cells offer new ALS insights
Geothermal aquifers offer green potential but quality checks required
Large Hadron Collider regularly makes magic
Functionality of a grapevine transport protein defined
Changes in store for atmospheric rivers
First results from 2021 rocket launch shed light on aurora’s birth
Patience isn't a virtue; it's a coping mechanism
The Lancet Psychiatry: Autism spectrum disorder ranks among the top 10 causes of non-fatal health burden in youth
Innovative glue maker chosen for Japanese startup program
Digital labels can help grocers waste less food
Clever trick to cook stars like Christmas puds detected for first time
By looking at individual atoms in tooth enamel, UW and PNNL researchers are learning what happens to our teeth as we age
Volunteers should not become friends with patients
Men and residents of higher crime areas see greater benefit from community parks, in reduction of deaths from heart disease
Getting rehab earlier improves concussion outcomes, OHSU study suggests
[Press-News.org] Breakthrough for laser-induced breakdown spectroscopyOvercoming limitations inherent in other LIBS techniques, plasma-grating-induced breakdown spectroscopy enhances signal intensity by more than three times