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Researchers provide new insights into fate of Franklin Expedition

2018/08/232018/09/03

Synchrotron studies of bone and teeth have led a multi-institution team of scientists to conclude that lead poisoning did not play a pivotal role in the deaths of crew members of the ill-fated Franklin Expedition of 1845, says a paper published today in the journal PLOS ONE.
“Our findings don’t mean the crew members weren’t exposed to high levels of lead, and they don’t mean the sailors weren’t impacted. But our findings don’t lend support to massive and sustained lead poisoning that would have compromised them any more than any sailor of that era would have been compromised,” said David Cooper of the University of Saskatchewan, an author of the paper.

Data collected by the team don’t support the theory that compromised physical and/or neurological health resulting from lead poisoning prompted the stranded sailors’ fatal march southward in April 1848 to try to reach a Hudson Bay Company post, said Cooper, Canada Research Chair in Synchrotron Bone Imaging in the Department of Anatomy, Physiology and Pharmacology at the U of S College of Medicine.
That theory arose from previous analyses of bone, hair and soft tissue samples from the frozen bodies of the sailors, which had found they had high levels of lead in their tissue.
The 11-member team includes Treena Swanston, who was a post-doctoral fellow on Cooper’s team at the U of S when the research began and is currently an assistant professor at MacEwan University. She is lead author of the paper.

Image: Sanjukta Choudhury (U of S), David Cooper (U of S), and Brian Bewer (CLS) at a CLS beamline.

Infrared beams show cell types in a different light

2018/08/232018/08/30

Berkeley Lab scientists developing new system to identify cell differences.

By shining highly focused infrared light on living cells, scientists at the U.S. Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab) hope to unmask individual cell identities, and to diagnose whether the cells are diseased or healthy.
They will use their technique to produce detailed, color-based maps of individual cells and collections of cells – in microscopic and eventually nanoscale detail – that will be analyzed using machine-learning techniques to automatically sort out cell characteristics.

Using microscopic color maps to unlock cell identity

Their focus is on developing a rapid way to easily identify cell types, and features within cells, to aid in biological and medical research by providing a way to probe living cells in their native environment without harming the cells or requiring obtrusive cell-labeling techniques.
“This is totally noninvasive,” said Cynthia McMurray, a biochemist and senior scientist in Berkeley Lab’s Molecular Biophysics and Integrated Bioimaging (MBIB) Division who is leading this new imaging effort with Michael Martin, a physicist and senior staff scientist at Berkeley Lab’s Advanced Light Source (ALS).
The ALS has dozens of beamlines that produce beams of intensely focused light, from infrared to X-rays, for a broad range of experiments.

Image: From left to right: Aris Polyzos, Edward Barnard, and Lila Lovergne, pictured here at Berkeley Lab’s Advanced Light Source, are part of a research team that is developing a cell-identification technique based on infrared imaging and machine learning.
Credit: Marilyn Chung/Berkeley Lab

SESAME appoints a new administrative director

2018/08/222018/08/30

SESAME, which is the first synchrotron light source in the Middle East and neighbouring countries and has now received its first users, has recently appointed Professor Walid Zidan as its new Administrative Director.

Professor Zidan, who took on this position at the beginning of this month, holds a PhD in chemical engineering from Alexandria University (Egypt), and has extensive experience in science and monitoring science and technology developments at national and international levels. He has 25 years experience in the public sector, starting from the Egyptian Atomic Energy Authority (EAEA) in 1993, moving on to also include the Egyptian Nuclear and Radiological Regulatory Authority (ENRRA) in 2012. For the seven years from 2007 to 2014 he was Supervisor of the Egyptian System for Nuclear Material Accounting and Control of the EAEA and ENRRA. From 2012 to 2014, he was then Head of the Nuclear Safeguards and Physical Protection Department of ENRRA, and in 2014, he became Vice Chair of ENRRA, as well as Rapporteur and National Coordinator of the Supreme Committee of Nuclear and Radiological Emergencies, two positions that he held until 2017 when he was appointed Vice Dean of the Division of Regulations and Nuclear Emergencies and Head of the Nuclear Safeguards and Physical Protection Department both of ENRRA.

In science, Professor Zidan has supervised several PhD and MSc theses and published 48 scientific articles in international journals. His publications focused on improving the operational performance of fuel cycle facilities through safe and secure management, nuclear material accountancy, criticality prevention, and process systems performance improvements.

>Read more on the SESAME website

SRI 2018 in Taipei

2018/08/222018/09/24

The 13th International Conference on Synchrotron Radiation Instrumentation (SRI 2018), attended by more than 850 participants from 25 countries, was hosted by the National Synchrotron Radiation Research Center (NSRRC) between June 10 to 15 at the Taipei International Convention Center. On the 11th, the Conference Chair, Director Shangjr Gwo of NSRRC, opened the conference, followed by a speech given by the vice president of the nation, Dr. Chien-Jen Chen.

The triennial SRI conference is a large and the most significant international forum, organized by the community of worldwide X-ray free electron laser (XFEL) and synchrotron radiation (SR) facilities, to provide opportunities for discussions and collaborations among scientists and engineers around the world involved in development of new concepts, techniques, and instruments related to SR and XFEL research. Subsequent meetings were hosted by countries with the most advanced light source facilities in Europe, America and Asia-Pacific region.

>Read more on the NSRRC website

Image: Vice President Chien-Jen Chen gave a speech in the opening session.

Graphene-Based Catalyst Improves Peroxide Production

2018/08/222018/08/30

Hydrogen peroxide is an important commodity chemical with a growing demand in many areas, including the electronics industry, wastewater treatment, and paper recycling.

Hydrogen peroxide (H₂O₂) is a common household chemical, well known for its effectiveness at whitening and disinfecting. It’s also a valuable commodity chemical used to etch circuit boards, treat wastewater, and bleach paper and pulp—a market expected to grow as demand for recycled paper products increases.

Compared to chlorine-based bleaches, hydrogen peroxide is more environmentally benign: the only degradation product of its use is water. However, it’s currently produced through a multistep chemical reaction that consumes significant amounts of energy, generates substantial waste, and requires a catalyst of palladium—a rare and expensive metal. Furthermore, the transport and storage of bulk hydrogen peroxide can be hazardous, making local, on-demand production highly desirable.

Better living through electrochemistry

Scientists seek a way to generate hydrogen peroxide electrochemically—by a much simpler process called the oxygen reduction reaction (ORR). This reaction takes oxygen from the air and combines it with water and two electrons to produce H₂O₂. If this reaction could be efficiently catalyzed, it could enable the disinfection of water at remote locations, or during disaster recovery, using hydrogen peroxide made from local air and water. For this work, the researchers focused on hydrogen peroxide synthesis in alkaline environments, where the reaction bath can be used directly, such as for bleaching or the treatment of acidic waste streams.

Image: The production of hydrogen peroxide (H₂O₂) from oxygen (O₂) was efficiently catalyzed by graphene oxide, a form of graphene characterized by various oxygen defects that act as centers for catalytic activity. Depicted are two types of defects: one in which an oxygen atom bridges two carbon atoms above the graphene plane, and one where oxygen atoms replace carbon atoms within the graphene plane.

Imaging the inner ear promises to be new gold standard for hearing researchers

2018/08/202018/08/23

Her interest in providing people who suffer from sensorineural hearing loss with a richer music-listening experience has led a young Harvard researcher to the Canadian Light Source (CLS) and to a discovery that opens the door to exciting new avenues for the study and diagnosis of human inner ear diseases.
“Hearing loss is such a widespread problem and my hope is that our work will eventually help us better diagnose and treat it. People are just not aware of how sensitive the auditory system is to trauma, and how isolating and depressing it can be to lose one’s ability to communicate fluidly with others,” says Janani Iyer, a PhD candidate in the Harvard-MIT Speech and Hearing Bioscience and Technology program.

A musician herself, Iyer came to Saskatoon to tackle the problem of how to create detailed images of the delicate structures that allow humans to hear.
“Part of what drew me to this is that, despite its prevalence, hearing loss is incredibly understudied and incredibly underfunded,” she said.

Amazing Aka adventure at the Taiwan Photon Source

2018/08/182018/09/24

NSRRC works hand in hand with the Golden Bell Award winner to successfully blend entertainment with scientific education in an exciting animated film “Aka’s adventure: the secret of light”.

The National Synchrotron Radiation Research Center (NSRRC) successfully hosted the “Taiwan Photon Source 2018 Open House Science Event” – a special film screening of the fine animated movie “Aka’s adventure: the secret of light” on Saturday August 18, 2018. Minister of Science and Technology Chen Liang-gee (陳良基), the winner of the Best Animation Program Golden Bell Award Li-Wei Chiu (邱立偉) and nearly 600 attendees gathered for this special event.

NSRRC is dedicated, not only to the pursuit of cutting edge research, but also to making science more accessible to the general public. This animated film is a first attempt by the NSRRC to reveal the achievements of frontier science using entertainment media. They have demonstrated how the distance between science and the general public can be shortened and brought to a whole new level. The seeds of scientific knowledge can easily be planted in the minds of youngsters.

>Read more on the NSRRC website

Image: A group photo of Science and Technology Minister Chen Liang-gee (陳良基), Director of the NSRRC Gwo-Huei Luo (羅國輝), former Director of the NSRRC Shangjr Gwo (果尚志) and movie director Li-Wei Chiu (邱立偉) from Studio2.

Specialized scientists from all over the world attending XRM2018

2018/08/162018/08/22

More than 300 experts from all over the world are coming to Saskatoon to explore one of the hottest fields in synchrotron science, putting the city on the global scientific map.

“X-ray microscopy is absolutely cutting-edge because both the technology and the applications are developing very rapidly,” says Stephen Urquhart, chair of the XRM2018 conference and a chemistry professor at the University of Saskatchewan. “These microscope techniques are quite powerful for a wide range of areas from scientists studying medicine to scientists studying materials. On the technology side, the developments in light sources also help with the development of more powerful and advanced microscopes.”

Synchrotrons, including the U of S Canadian Light Source, produce light that’s millions of times brighter than the sun. Using the X-ray portion of the electromagnetic spectrum, scientists shine that light on what they are studying and then use specially designed microscopes to study matter at the molecular level. The CLS has five beamlines dedicated to X-ray microscopy.

The X-ray microscopy experts attending XRM2018 will be coming from 24 countries. During the week-long conference, 76 leaders in this field of science will present their research findings. In addition, 200 scientific posters will be on display. “We are doing good things at the Canadian Light Source and by hosting the meeting here we get a chance to highlight the work that we do to people around the globe,” says Urquhart, who adds that the recent shut-down at the CLS due an equipment failure won’t interfere with the conference.

Synchrotron infrared beamline optics optimized…

2018/08/162018/10/23

…for nano-scale vibrational spectroscopy. First experimental report of a special optical layout dedicated to correct typical aberrations derived from large extraction ports in IR beamlines.

Infrared nanospectroscopy represents a major breakthrough in chemical analysis since it allows the identification of nanomaterials via their natural (label free) vibrational signatures. Classically powered by laser sources, the experiment called scattering Scanning Near-field Optical Microscopy (s-SNOM) has become a standard tool for investigations of chemical and optical properties of materials beyond the diffraction limit of light.

Lately, s-SNOM is achieving unprecedent sensitivity range by exploring the outstanding spectral irradiance of synchrotron light sources in the full range of infrared (IR) radiation. In the last few years, the combination of s-SNOM and ultra-broadband IR synchrotron (SINS or nano-FTIR) has helped studies in relevant scientific fronts involving atomic layered materials, fundamental optics, nanostructured bio-materials and, very recently, it was demonstrated to be feasible to work in the far-IR.

IR ports in synchrotron storage rings can be up to a thousand times more brilliant than classical IR black body sources. This advantage allowed IR beamlines to be the only places capable of performing IR micro-spectroscopy for many years. However, in comparison to X-ray ports, IR beamlines require large apertures for allowing long wavelengths to be extracted. Consequently, IR beamlines typically present optical aberrations such as extended source depth and coma.

Images (extracts): Figure 1 – Proposed optical layout, IR extraction chamber indicating the source depth, conical mirror illustration, aberration-corrected focal spot at the sample stage and nano-FTIR experimental scheme in operation in the IR endstation of the LNLS. Figure adapted from R. Freitas et al., Optics Express 26, 11238 (2018).

Science Village gets go-ahead to start construction

2018/08/162018/08/16

The detailed development plan for Science Village gets a green light from the Government of Sweden which means that the construction of important support infrastructure for MAX IV and ESS can now start.

“This decision is obviously good for us. We welcome it and we have been waiting for a long time. We are happy for several reasons – in general, MAX IV needs neighbors to interact with, so this is an important step in that direction. The first project for us is the SPACE building that will be constructed for ESS and MAX IV in the near future. In the somewhat more distant future, Lund University plan to move a significant part of their activities to Brunnshög. For that, a green light from the government is mandatory and very much appreciated”, says Christoph Quitmann, Director of MAX IV.

>Read more about the Science Village.

Illustration: ESS

Topological excitations emerge from a vibrating crystal lattice

2018/08/152018/08/30

It has long been known that the properties of materials are crucially dependent on the arrangement of the atoms that make up the material. For example, atoms that are further apart will tend to vibrate more slowly and propagate sound waves more slowly. Now, researchers from Brookhaven National Laboratory have used Sector 30 at the Advanced Photon Source (APS) to discover “topological” vibrations in iron silicide (FeSi). These topological vibration arise from a special symmetrical arrangement of the atoms in FeSi and endow the atomic vibrations with novel properties such as the potential to transmit sound waves along the edge of the materials without scattering and dissipation. Looking to the future one might envisage using these modes to transfer energy or information within technological devices.

In quantum mechanics, atomic motions in crystals are described in terms of vibrational modes called phonons. Similar to electrons moving in metals, phonons can also propagate through materials. The detailed properties of these excitations determine many of the thermal, mechanical and electronic properties of the material. In 2017, part of the current collaborative team from the Chinese Academy of Science, theoretically predicted the existence of the topological phonons in transition metal monosilicides. As shown in Fig.1, these topological phonons are formed by two Dirac-cones with different slopes and are protected by symmetry. Since the mathematical description of each Dirac-cone is intimately related to the famous Weyl-equation that was originally proposed in high-energy physics, these topological phonons are consequently called double-Weyl excitations.

Image: (extract) Schematic view of the double-Weyl phonon dispersion. Full image here.
Credit: Brookhaven National Laboratory

Breakthrough for body heat-powered technologies

2018/08/152018/08/15

One of the biggest challenges for the advancement of wearable devices, embedded to clothing and accessories, which would be capable, for example, of continuously measuring and transmitting vital sign data, is the availability of power without the need for large batteries.

Thermoelectric materials – in which a temperature difference between two points of the material creates an electric current or vice versa – make it possible to obtain the electrical energy used by the device from the temperature difference between the surface of the human body and the ambient air.

The efficiency of these materials is characterized by their figure of merit $z T$ , which is directly proportional to the electrical conductivity and the absolute temperature of the material and inversely proportional to its thermal conductivity. Thus, obtaining new materials with high value for $z T$ at room temperature and low thermal conductivity is a key element for the development of a new generation of wearable devices based on thermoelectric heat recovery.

>Read more on the LNLS website

Magnetic vortices observed in haematite

2018/08/132018/09/03

Magnetic vortices observed in antiferromagnetic haematite were transferred into ferromagnetic cobalt.

Vortices are common in nature, but their formation can be hampered by long range forces. In work recently published in Nature Materials, an international team of researchers has used mapped X-ray magnetic linear and circular dichroism photoemission electron microscopy to observe magnetic vortices in thin films of antiferromagnetic haematite, and their transfer to an overlaying ferromagnetic sample. Their results suggest that the ferromagnetic vortices may be merons, and indicate that vortex/meron pairs can be manipulated by the application of an in-plane magnetic field, giving rise to large-scale vortex–antivortex annihilation. Ferromagnetic merons can be thought of as topologically protected spin ‘bits’, and could potentially be used for information storage in meron racetrack memory devices, similar to the skyrmion racetrack memory devices currently being considered.

Image: Graphic outlining the antiferromagnetic rust vortices. The grayscale base layer represents the (locally collinear) magnetic order in the rust layer, and the coloured arrows the magnetic order imprinted into the adjacent Co layer.

World record: Fastest 3D tomographic images at BESSY II

2018/08/082018/08/09

An HZB team has developed an ingenious precision rotary table at the EDDI beamline at BESSY II and combined it with particularly fast optics.

This enabled them to document the formation of pores in grains of metal during foaming processes at 25 tomographic images per second – a world record.

The quality of materials often depends on the manufacturing process. In casting and welding, for example, the rate at which melts solidify and the resulting microstructure of the alloy is important. With metallic foams as well, it depends on exactly how the foaming process takes place. To understand these processes fully requires fast sensing capability. The fastest 3D tomographic images to date have now been achieved at the BESSY II X-ray source operated by the Helmholtz-Zentrum Berlin.

Dr. Francisco Garcia-Moreno and his team have designed a turntable that rotates ultra-stably about its axis at a constant rotational speed. This really depends on the highest precision: Any tumbling around the rotation axis or even minimal deviations in the rotation speed would prevent the reliable calculation of the 3D tomography. While commercially available solutions costing several hundred thousand euros allow up to 20 tomographic images per second, the Berlin physicists were able to develop a significantly cheaper solution that is even faster. ”My two doctoral students at the Technische Universität Berlin produced the specimen holders themselves on the lathe”, says Garcia-Moreno, who not only enjoys working out solutions to tricky technical problems, but possesses a lot of craftsman skill himself as well. Additional components were produced in the HZB workshop. In addition, Garcia-Moreno and his colleague Dr. Catalina Jimenez had already developed specialized optics for the fast CMOS camera during the preliminary stages of this work that allows even for simultaneous diffraction. This makes it possible to record approximately 2000 projections per second, from which a total of 25 three-dimensional tomographic images can be created.

Image: Experimental setup is composed of a fast-rotation stage, an IR heating lamp (temperature up to 800 °C), a BN crucible transparent to X-rays, a 200-μm thick LuAG:Ce scintillator, a white-beam optical system, and a PCO Dimax CMOS camera. The incident (red) and transmitted (green) X-ray beams as well as the light path from the scintillator to the camera (blue) are shown.
Credit: HZB

Research gives clues to CO2 trapping underground

2018/08/082018/08/09

CO2 is an environmentally important gas that plays a crucial role in climate change.

It is a compound that is also present in the depth of the Earth but very little information about it is available. What happens to CO2 in the Earth’s mantle? Could it be eventually hosted underground? A new publication in Nature Communications unveils some key findings.

Carbon dioxide is a widespread simple molecule in the Universe. In spite of its simplicity, it has a very complex phase diagram, forming both amorphous and crystalline phases above the pressure of 40 GPa. In the depths of the Earth, CO₂ does not appear as we know it in everyday life. Instead of being a gas consisting of molecules, it has a polymeric solid form that structurally resembles quartz (a main mineral of sand) due to the pressure it sustains, which is a million times bigger than that at the surface of the Earth.

Researchers have been long studying what happens to carbonates at high temperature and high pressure, the same conditions as deep inside the Earth. Until now, the majority of experiments had shown that CO₂ decomposes, with the formation of diamond and oxygen. These studies were all focused on CO₂ at the upper mantle, with a 70 GPa of pressure and 1800-2800 Kelvin of temperature.

Picture: Mohamed Mezouar, scientist in charge of ID27, on the beamline.
Credit: S. Candé.

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