XRF – Lightsources.org

Protecting Saskatchewan lakes from contamination

2020/10/192020/10/19

Using the Canadian Light Source synchrotron, a University of Saskatchewan-led research team has developed a method for monitoring uranium contaminants in mine tailings using samples from McClean Lake, SK.

While mining companies work to extract as much uranium as possible from processed ore, small amounts remain in the solid and liquid residue—called tailings—left over from the milling process.

To protect the downstream environment from potential impacts of the solid waste, the Canadian Nuclear Safety Commission requires companies to monitor the chemistry of uranium and other potentially harmful elements in their tailings facilities.

Numerous researchers have studied the chemistry of nickel, arsenic, selenium and molybdenum in Orano Canada’s tailings management facility at McClean Lake, but to date little was known about residual uranium. One of the challenges has been the extremely low concentrations of the element left after processing at Orano’s ore mill, which began operating in 1997.

Read more on the Canadian Light Source website

Image: Arthur Situm conducting research at SXRMB beamline. Photo by David Stobbe for USask.

Monitoring food safety of marine fishes

2019/08/282019/09/19

Research investigates ways to convert titanium dioxide into a new photoactive material in the visible light range.

The search for clean and renewable energy sources has intensified in recent years due to the increase in atmospheric concentration of greenhouse gases and the consequent increase in the average temperature of the planet. One such alternative source is the conversion of sunlight into electricity through photovoltaic panels. The efficiency in this conversion depends on the intrinsic properties of the materials used in the manufacturing of the panels, and it increases year by year with the discovery of new and better materials. As such, solar energy is expected to become one of the main sources of electric energy by the middle of this century, according to the International Energy Agency (IEA).

Titanium dioxide ( $T i O_{2}$ ) is an abundant, nontoxic, biologically inert and chemically stable material, known primarily as a white pigment used in paints, cosmetics and even toothpastes. $T i O_{2}$ is also often used in sunscreens since it is especially capable of absorbing radiation in the ultraviolet region. However, this same property severely limits the use of $T i O_{2}$ for solar energy conversion, since the ultraviolet emission comprises only 5 to 8% of the total energy of the solar light. Can this $T i O_{2}$ property be extended to the visible light region to increase the conversion of sunlight into electricity? To answer this question, Maria Pilar de Lara-Castells et al. [1] conducted an innovative research in which they discuss how a special treatment can change the optical properties of $T i O_{2}$ .

>Read more on the LNLS website

Image: Joakant (Pixabay)

Publication of the first scientific paper

2019/06/192019/06/19

June 1, 2019 marks a historically important accomplishment for SESAME, where the very first scientific paper presenting results using data obtained at SESAME’s X-ray absorption fine structure/X-ray fluorescence (XAFS/XRF) spectroscopy beamline was published in Applied Catalysis B: Environmental.

S: Bac et al. Applied Catalysis B: Environmental, 259, 2019, 117808 https://www.sciencedirect.com/science/article/pii/S0926337319305545

Synchrotron measurements performed at SESAME were carried out by the research group of Associate Professor Emrah Ozensoy (Bilkent University Chemistry Department and UNAM-National Nanotechnology Center Ankara, Turkey), in collaboration with the research group of Professor Ahmet Kerim Avcı (Boğaziçi University, Chemical Engineering Department, Istanbul, Turkey) and Dr Messaoud Harfouche (XAFS/XRF beamline scientist, SESAME, Allan, Jordan).
The paper entitled Exceptionally active and stable catalysts for CO2 reforming of glycerol to syngas is the outcome of a measurement campaign at SESAME in July 2018 and focuses on the catalytic valorization of a biomass waste material (i.e. glycerol) to obtain synthesis gas (or syngas, CO + H2). Glycerol is an important renewable feedstock for the large-scale catalytic production of synthetic liquid fuels through a process called Fischer-Tropsch synthesis. In the words of Emrah Ozensoy “XAFS/XRF experiments performed at SESAME were instrumental for us to understand the electronic structure of the Co/CoOx and Ni/NiOx nanoparticles serving as the catalytic active sites. Particularly, complementing the experimental data acquired in our labs with the results obtained at SESAME allowed us to examine the nature of the fresh catalysts and compare them with that of the spent catalysts obtained after the catalytic reaction, revealing crucial molecular-level insights regarding the catalytic aging and poisoning mechanisms.”

>Read more on the SESAME website

Image: Kerem Emre Ercan Some of the researchers who contributed to the publication and data acquisition (from left to right, Yusuf Koçak, Kerem E. Ercan, and M. Fatih Genişel)

Synchrotron techniques allow geologists to study the surface of Mars

2019/05/032019/05/06

State-of-the-art imaging uncovers the exciting life history of an unusual Mars meteorite

With human and sample-return missions to Mars still on the drawing board, geologists wishing to study the red planet rely on robotic helpers to collect and analyse samples. Earlier this year we said goodbye to NASA’s Opportunity rover, but Insight landed in November 2018, and several space agencies have Mars rover missions on their books for the next few years. But while we’re working on ways to bring samples back from Mars, geologists can study Martian meteorites that have been delivered to us by the forces at play in the Solar System. Earth is bombarded by tonnes of extraterrestrial material every day. Most of it comes from Jupiter Family Comets and the asteroid belt, and much of it burns up in the atmosphere or lands in the oceans, but meteorites from the Moon and Mars do make it to Earth’s surface. In research published in Geochimica et Cosmochimica Acta, scientists used a battery of synchrotron techniques to investigate a very unusual Martian meteorite, whose eventful life story offers some insights to the geological history of Mars.

Image: BSE image with locations for XANES/XRD and XRF map.

X-ray fluorescence sheds light on the growth patterns of extinct hyaena

2019/03/152019/03/18

A novel synchrotron technique examines growth patterns in fossil bones

Until recently, it was thought that warm-blooded animals experienced uninterrupted high rates of growth, whilst cold-blooded animals showed zonal growth – alternating periods of fast and slow growth. The identification of zonal growth in a range of mammals and birds disproved that theory, but as yet we don’t know how widespread zonal growth is in vertebrates, or which factors affect the speed of bone growth. Conventional techniques lack the resolution to correlate variations in bone chemistry with histological features, but in work recently published in the Journal of Analytical Atomic Spectrometry, an international team of researchers carried out the first direct comparison between optical histology (bone tissue identification) and synchrotron-based chemical mapping, quantification, and characterisation of trace elements (biochemistry) within cyclic growth tissues, and reported the first case of zonal tissue within the Hyaenidae.

Image: Lead author Jennifer Anné with a spotted hyaena mount.

Mapping terrestrial analogs for martian samples

2019/01/092019/01/24

Internships at Brookhaven’s National Synchrotron Light Source II helped turn her love for rocks into serious study.

Catherine Trewhella, a recent graduate from the University of Massachusetts, Amherst, and current intern at the U.S. Department of Energy’s (DOE) Brookhaven National Laboratory, is taking a microscopic look at rocks at the National Synchrotron Light Source II (NSLS-II), a DOE Office of Science user facility. Her research will help prepare scientists for analyzing samples brought back from outer space, specifically Mars.
Trewhella is currently interning as a part of Brookhaven Lab’s Office of Educational Programs’ Supplemental Undergraduate Research Program (SURP). Over the course of the fall, she has been using NSLS-II’s Submicron Resolution X-ray Spectroscopy (SRX) beamline to map out the chemical make-up of terrestrial analogs for Martian samples.
“They’re terrestrial rocks,” she said. “But what makes them worth the closer look is researchers believe they’re similar to rock formations expected on Mars.” These x-ray fluorescence images (XRF) will therefore help scientists better understand what they are seeing when studying Martian samples.

Image: Catherine Trewhella at the Submicron Resolution X-ray Spectroscopy (SRX) beamline at the National Synchrotron Light Source II (NSLS-II) at Brookhaven Lab.

Plant roots police toxic pollutants

2018/08/062018/08/09

X-ray studies reveal details of how P. juliflora shrub roots scavenge and immobilize arsenic from toxic mine tailings.

Working in collaboration with scientists at the U.S. Department of Energy’s Brookhaven National Laboratory and SLAC National Accelerator Laboratory, researchers at the University of Arizona have identified details of how certain plants scavenge and accumulate pollutants in contaminated soil. Their work revealed that plant roots effectively “lock up” toxic arsenic found loose in mine tailings—piles of crushed rock, fluid, and soil left behind after the extraction of minerals and metals. The research shows that this strategy of using plants to stabilize pollutants, called phytostabilization, could even be used in arid areas where plants require more watering, because the plant root activity alters the pollutants to forms that are unlikely to leach into groundwater.

The Arizona based researchers were particularly concerned with exploring phytostabilization strategies for mining regions in the southwestern U.S., where tailings can contain high levels of arsenic, a contaminant that has toxic effects on humans and animals. In the arid environment with low levels of vegetation, wind and water erosion can carry arsenic and other metal pollutants to neighboring communities.

Image: Scientists from the University of Arizona collect plant samples from the mine tailings at the Iron King Mine and Humboldt Smelter Superfund site in central Arizona. X-ray studies at Brookhaven Lab helped reveal how these plants’ roots lock up toxic forms of arsenic in the soil.
Credit: Jon Chorover

SESAME hosts its first users

2018/08/032018/08/09

Mid July, the first users arrived at SESAME to perform experiments using the Centre’s XAFS/XRF (X-ray absorption fine structure/X-ray fluorescence) spectroscopy beamline, SESAME’s first beamline to come into operation.

This was the Finnish Kirsi Lorentz and three of her colleagues at The Cyprus Institute: the Cypriot Grigoria Ioannou, the Japanese Yuko Miyauchi and the Greek/Egyptian Iosif Hafez, who together form a true international team in the spirit of SESAME.

Kirsi is the author of one of the 19 proposals from 5 of the SESAME Members (Cyprus, Egypt, Jordan, Pakistan and Turkey) that have been recommended for a total of 95.8 hour shifts on the XAFS/XRF beamline by SESAME’s Proposal Review Committee (PRC). The PRC is an international advisory body that evaluates the scientific and technological merit of proposals from the General Users and determines their priority using criteria based on IUPAP’s Recommendations for the Use of Major Physics Users Facilities.

“This heralds in a new stage in SESAME’s march forward, and for scientists in the SESAME Members and the region it is the tangible beginning of a moment from when it becomes possible to carry out state-of-the-art research in the region” said Khaled Toukan, Director of SESAME.

“It is a unique opportunity and a real honour to be the first user of a synchrotron light facility – a research visit to remember” said Kirsi, who is examining ancient human remains from the Eastern Mediterranean and the Near East, adding “we are very excited with the results we obtained at the SESAME XAFS/XRF beamline, and grateful to all those who have worked so hard to bring this crucial research facility into operation in our region”.

>Read more on the SESAME website

Picture: Kirsi Lorentz, The Cyprus Institute: Kirsi Lorentz and her research team (from left to right: Yuko Miyauchi, Grigoria Ioannou, Kirsi Lorentz and Iosif Hafez) at the XAFS/XRF beamline control hutch.

Hidden medical text read for the first time in a thousand years

2018/03/222018/03/28

With X-ray imaging at SLAC’s synchrotron, scientists uncovered a 6th century translation of a book by the Greek-Roman doctor Galen.

An influential physician and a philosopher of early Western medicine, Galen of Pergamon was the doctor of emperors and gladiators. One of his many works, “On the Mixtures and Powers of Simple Drugs,” was an important pharmaceutical text that would help educate fellow Greek-Roman doctors.

The text was translated during the 6^th century into Syriac, a language that served as a bridge between Greek and Arabic and helped spread Galen’s ideas into the ancient Islamic world. But despite the physician’s fame, the most complete surviving version of the translated manuscript was erased and written over with hymns in the 11^th century – a common practice at the time. These written-over documents are known as palimpsests.

An international team of researchers is getting a clear look at the hidden text of the Syriac Galen Palimpsest with an X-ray study at the Stanford Synchrotron Radiation Lightsource (SSRL) at the Department of Energy’s SLAC National Accelerator Laboratory.

Image: Conservators at Stanford University Libraries removed the pages from the leather-bound cover of the book of hymns, and mounted each leaf in an individually fitted, archival mat. The individual mats were placed in an aluminum frame to secure the pages while examining the underlying text with X-rays at the Stanford Synchrotron Radiation Lightsource.
Credit: Farrin Abbott / SLAC National Accelerator Laboratory