physicsworld--2020-07-06--Cryogenics makes the European Spallation Source a hot property in neutron science - Physics World

Large-scale neutron facilities – one of the mainstays of Europe ’ s “ big science ” infrastructure – are routinely used by researchers to understand material properties on the atomic scale , spurring advances across a spectrum of scientific discovery – from clean energy and environmental technology to pharma and healthcare , from structural biology and nanotech to food science and cultural heritage .
Industry users , meanwhile , use neutrons to probe deep into engineering components , gaining unique insights into the stresses and strains that affect turbine blades , gas pipelines , fuel cells and the like .
@ @ @ @ @ @ @ thinking bigger – and neutron science is no exception .
For the neutron user community , in fact , a decade of revolution rather than evolution is hoving into view as construction progresses on the European Spallation Source ( ESS ) , a €1.84bn accelerator-driven neutron source in Lund , Sweden .
When it comes online for user experiments in 2023 , the ESS will be the world ’ s most powerful neutron source – between 20 and 100 times brighter than the Institut Laue Langevin ( ILL ) in Grenoble , France @ @ @ @ @ @ @ powerful than the Spallation Neutron Source ( SNS ) in Oak Ridge , Tennessee , US .
That big leap forward represents an industrial-scale undertaking , an amalgam of the most powerful linear proton accelerator ever built ; a two-tonne , rotating tungsten target wheel ( which produces neutrons via the spallation process ) ; 22 state-of-the-art neutron instruments for user experiments ; and a high-performance data management and software development centre ( located in Copenhagen ) .
John G Weisend II , group leader for specialized technical services at ESS , explains @ @ @ @ @ @ @ production and maintenance of temperatures as low as 2 K – are equally fundamental to the ESS ’ s long-term scientific success .
What are the main building blocks of the ESS cryogenics programme ?
There are three principal applications of helium cryogenics within the ESS .
The proton linac ’ s superconducting RF cryomodules ( responsible for the bulk of the particle acceleration ) require cooling at 2 K , 4.5 K and 40 K , while the hydrogen moderator ( surrounding the tungsten target that produces the neutrons ) requires cooling @ @ @ @ @ @ @ , many of the facility ’ s scientific instruments will rely on liquid helium to cool hardware like superconducting magnets or to provide low-temperature environments around the instruments and sample chambers themselves .
To meet these needs , we specified a system design with three distinct cryogenic refrigeration plants sharing a largely common recovery , purification and storage system ( see “ The headline take on ESS ” below ) .
After an open tendering process , Linde emerged as our chosen supplier for the accelerator cryoplant and target moderator cryoplant , with @ @ @ @ @ @ @ and instruments cryoplant as well as the recovery and purification system .
How did you approach that engagement with industry ?
One of the challenges with a cryogenic system of this scale is the lead time – more than five years from the initial feasibility studies and the writing of the detailed technical specifications through to the on-site installation and commissioning at ESS .
As such , it ’ s vital to get under way early with the cryoplant design studies and equipment procurement .
Although the three ESS cryoplants are by no @ @ @ @ @ @ @ not to be overly innovative in terms of our requirements-gathering .
Instead , the emphasis was on capital cost , best-in-class reliability and minimizing operating expenditure – chiefly through energy efficiency .
That commitment to sustainability is a unique aspect of the ESS project .
What does this mean for the cryogenics programme ?
One aspect of the ESS sustainability plan is to recover as much waste heat as possible – at least 50 % – and supply it into the domestic hot-water heating system in the Lund metro area .
Across all @ @ @ @ @ @ @ the heat deposited in the oil and helium coolers of the warm compressors as well as in the compressor motors .
Does the emphasis on sustainability extend to helium recovery and storage ?
Helium is a finite resource and an industrial gas that ’ s subject to significant price fluctuations .
With this in mind , all of our cryogenic operating cycles are closed , designed to limit the venting of helium into the atmosphere to a few , rare failure modes .
Over the next five years , as we commission and @ @ @ @ @ @ @ , we expect to replace approximately 50 % of our helium inventory each year .
Beyond that , we aim to get down below 25 % replacement levels per annum .
Many ESS project partners make “ in-kind ” contributions of equipment and personnel rather than direct cash investments from the member countries .
How does this work in terms of the cryogenics programme ?
A good example is the cryogenic distribution system , which connects the accelerator cryoplant to the cryomodules in the accelerator tunnel and , uniquely , is set up @ @ @ @ @ @ @ independently cool down or warm up any of the cryomodules while keeping the others at their operating temperature .
This capability allows us to repair a specific cryomodule in situ while keeping the others at cryogenic temperatures – the aim being to reduce downtime and improve the availability of ESS for the scientific users .
Unlike the rest of the cryogenic infrastructure , the distribution system is provided by in-kind partners , with the bulk of the work carried out by Wroclaw University of Science and Technology in Poland and its local industry @ @ @ @ @ @ @ by the Laboratoire de Physique des 2 Infinis Irène Joliot-Curie in France and its industry partner Cryo Diffusion .
It ’ s worth noting that these relationships are very much in the spirit of scientific collaboration rather than contractor/subcontractor arrangements .
How has the ESS construction project been impacted by the coronavirus pandemic ?
While most ESS staff are working from home , civil construction proceeds almost as normal and a significant amount of installation of technical infrastructure is still taking place on site .
However , ESS depends on deliveries and interaction @ @ @ @ @ @ @ and we see that the supply chain has been affected by the pandemic .
In terms of the cryogenics deployment , current status is that the test and instruments cryoplant is fully commissioned and turned over to us , as is the target moderator cryoplant .
The accelerator cryoplant has been commissioned to its highest-capacity cooling at 2 K. Working with Linde , we expect to complete the commissioning this summer .
The last part of the cryogenic distribution system has been delayed , but we do expect to commission it in early @ @ @ @ @ @ @ projects learn from your experience at ESS ?
We ’ ve done a lot of things right on the ESS cryogenics programme .
Big science is all about collaboration , so the number-one priority , from the off , is to have tight communication with your industry vendors and in-kind project partners .
Communication needs to work consistently well at all levels – from the director right down to the project engineers at the sharp end .
We also carved out time on personnel and recruitment , building a world-class , 10-strong team @ @ @ @ @ @ @ technicians to manage and work with a diverse group of stakeholders .
On the flip side , one area to guard against is over-reach .
A case in point is a project that we took on in-house and underestimated – building the warm-gas connections between the three cryoplants and cryogen storage systems .
While we wound up getting the work done on time , it probably would have been prudent – and less stressful – to allocate more resource earlier .
We share all of these lessons via regular conference presentations and exchange @ @ @ @ @ @ @ facilities .
What ’ s next for you and the ESS cryogenics team ?
The pace is relentless and likely to be even more so once we get beyond the pandemic .
Commissioning of the accelerator cryoplant and the cryogenic distribution system should be completed in 2020 , while installation of the cryomodules in the linac tunnel should start at the end of the year and continue through 2021 .
The first cooldown of the ESS linac is planned for 2022 .

Cryogenics is a core enabling technology at the European Spallation Source, a next-generation neutron-science facility under construction in Sweden. Joe McEntee talks to John G Weisend II, group leader for specialized technical services at ESS, about the secrets of success at ultralow temperatures
Big science: an aerial view over the ESS construction site in Lund, Sweden, taken in February 2020. (Courtesy: Perry Nordeng/ESS)
Large-scale neutron facilities – one of the mainstays of Europe’s “big science” infrastructure – are routinely used by researchers to understand material properties on the atomic scale, spurring advances across a spectrum of scientific discovery – from clean energy and environmental technology to pharma and healthcare, from structural biology and nanotech to food science and cultural heritage. Industry users, meanwhile, use neutrons to probe deep into engineering components, gaining unique insights into the stresses and strains that affect turbine blades, gas pipelines, fuel cells and the like.
Big science, of course, keeps thinking bigger – and neutron science is no exception. For the neutron user community, in fact, a decade of revolution rather than evolution is hoving into view as construction progresses on the European Spallation Source (ESS), a €1.84bn accelerator-driven neutron source in Lund, Sweden. When it comes online for user experiments in 2023, the ESS will be the world’s most powerful neutron source – between 20 and 100 times brighter than the Institut Laue Langevin (ILL) in Grenoble, France, and up to five times more powerful than the Spallation Neutron Source (SNS) in Oak Ridge, Tennessee, US.
John G Weisend II: “Big science is all about collaboration, so the number-one priority, from the off, is to have tight communication with your industry vendors and in-kind project partners.” (Courtesy: ESS)
That big leap forward represents an industrial-scale undertaking, an amalgam of the most powerful linear proton accelerator ever built; a two-tonne, rotating tungsten target wheel (which produces neutrons via the spallation process); 22 state-of-the-art neutron instruments for user experiments; and a high-performance data management and software development centre (located in Copenhagen). John G Weisend II, group leader for specialized technical services at ESS, explains how liquid-helium cryogenic technologies – which enable production and maintenance of temperatures as low as 2 K – are equally fundamental to the ESS’s long-term scientific success.
What are the main building blocks of the ESS cryogenics programme?
There are three principal applications of helium cryogenics within the ESS. The proton linac’s superconducting RF cryomodules (responsible for the bulk of the particle acceleration) require cooling at 2 K, 4.5 K and 40 K, while the hydrogen moderator (surrounding the tungsten target that produces the neutrons) requires cooling via 16.5 K supercritical helium.
Elsewhere, many of the facility’s scientific instruments will rely on liquid helium to cool hardware like superconducting magnets or to provide low-temperature environments around the instruments and sample chambers themselves.
To meet these needs, we specified a system design with three distinct cryogenic refrigeration plants sharing a largely common recovery, purification and storage system (see “The headline take on ESS” below). After an open tendering process, Linde emerged as our chosen supplier for the accelerator cryoplant and target moderator cryoplant, with Air Liquide contracted to supply the test and instruments cryoplant as well as the recovery and purification system.
How did you approach that engagement with industry?
One of the challenges with a cryogenic system of this scale is the lead time – more than five years from the initial feasibility studies and the writing of the detailed technical specifications through to the on-site installation and commissioning at ESS. As such, it’s vital to get under way early with the cryoplant design studies and equipment procurement. Although the three ESS cryoplants are by no means off-the-shelf solutions, we were careful not to be overly innovative in terms of our requirements-gathering. Instead, the emphasis was on capital cost, best-in-class reliability and minimizing operating expenditure – chiefly through energy efficiency.
Keeping cool: two of the three ESS “cold-boxes” – the target moderator cryoplant (left) and accelerator cryoplant (right) – were supplied by Linde. (Courtesy: Ulrika Hammarlund/ESS)
That commitment to sustainability is a unique aspect of the ESS project. What does this mean for the cryogenics programme?
One aspect of the ESS sustainability plan is to recover as much waste heat as possible – at least 50% – and supply it into the domestic hot-water heating system in the Lund metro area. Across all our cryogenics systems, we are recovering the heat deposited in the oil and helium coolers of the warm compressors as well as in the compressor motors.
Does the emphasis on sustainability extend to helium recovery and storage?
Helium is a finite resource and an industrial gas that’s subject to significant price fluctuations. With this in mind, all of our cryogenic operating cycles are closed, designed to limit the venting of helium into the atmosphere to a few, rare failure modes. Over the next five years, as we commission and put the ESS cryoplant through its paces, we expect to replace approximately 50% of our helium inventory each year. Beyond that, we aim to get down below 25% replacement levels per annum.
Many ESS project partners make “in-kind” contributions of equipment and personnel rather than direct cash investments from the member countries. How does this work in terms of the cryogenics programme?
A good example is the cryogenic distribution system, which connects the accelerator cryoplant to the cryomodules in the accelerator tunnel and, uniquely, is set up in such a way that we can independently cool down or warm up any of the cryomodules while keeping the others at their operating temperature. This capability allows us to repair a specific cryomodule in situ while keeping the others at cryogenic temperatures – the aim being to reduce downtime and improve the availability of ESS for the scientific users.
Unlike the rest of the cryogenic infrastructure, the distribution system is provided by in-kind partners, with the bulk of the work carried out by Wroclaw University of Science and Technology in Poland and its local industry partner Kriosystem; the remainder is handled by the Laboratoire de Physique des 2 Infinis Irène Joliot-Curie in France and its industry partner Cryo Diffusion. It’s worth noting that these relationships are very much in the spirit of scientific collaboration rather than contractor/subcontractor arrangements.
The long view: this section of the cryogenic distribution system in the ESS accelerator tunnel is an in-kind contribution from Poland. (Courtesy: Ulrika Hammarlund/ESS)
How has the ESS construction project been impacted by the coronavirus pandemic?
While most ESS staff are working from home, civil construction proceeds almost as normal and a significant amount of installation of technical infrastructure is still taking place on site. However, ESS depends on deliveries and interaction with our in-kind partners and suppliers, and we see that the supply chain has been affected by the pandemic.
In terms of the cryogenics deployment, current status is that the test and instruments cryoplant is fully commissioned and turned over to us, as is the target moderator cryoplant. The accelerator cryoplant has been commissioned to its highest-capacity cooling at 2 K. Working with Linde, we expect to complete the commissioning this summer. The last part of the cryogenic distribution system has been delayed, but we do expect to commission it in early 2021.
What lessons can other big-science projects learn from your experience at ESS?
We’ve done a lot of things right on the ESS cryogenics programme. Big science is all about collaboration, so the number-one priority, from the off, is to have tight communication with your industry vendors and in-kind project partners. Communication needs to work consistently well at all levels – from the director right down to the project engineers at the sharp end. We also carved out time on personnel and recruitment, building a world-class, 10-strong team of engineers, scientists, designers and technicians to manage and work with a diverse group of stakeholders.
On the flip side, one area to guard against is over-reach. A case in point is a project that we took on in-house and underestimated – building the warm-gas connections between the three cryoplants and cryogen storage systems. While we wound up getting the work done on time, it probably would have been prudent – and less stressful – to allocate more resource earlier. We share all of these lessons via regular conference presentations and exchange visits with our counterparts from other large-scale facilities.
What’s next for you and the ESS cryogenics team?
The pace is relentless and likely to be even more so once we get beyond the pandemic. Commissioning of the accelerator cryoplant and the cryogenic distribution system should be completed in 2020, while installation of the cryomodules in the linac tunnel should start at the end of the year and continue through 2021. The first cooldown of the ESS linac is planned for 2022.
The European Spallation Source: an overview Under pressure: part of the compressor system for the ESS target moderator cryoplant. (Courtesy: Ulrika Hammarlund/ESS) Fundamental principles At the heart of the ESS is a linear accelerator that produces up to a 5 MW beam of 2 GeV protons, with the bulk of the acceleration generated by more than 100 superconducting RF cavities.
These protons strike a rotating tungsten target wheel to produce a beam of neutrons via a process known as nuclear spallation (i.e. the impact on the tungsten nuclei effectively “spalls” off free neutrons).
The resulting neutrons pass through a supercritical hydrogen moderator (at about 17 K), slowing them to useful energies before distribution to a suite of 22 neutron-science instruments. Cryogenic requirements All the superconducting RF cavities in the proton linac operate in saturated 2 K liquid-helium baths.
The supercritical hydrogen moderator absorbs up to 30 kW from the spallation neutrons; the heat is removed by a hydrogen/helium heat exchanger that is in turn cooled by a 15 K supercritical helium flow.
The neutron-science instruments require a maximum of 7500 L/month of liquid helium for cooling of components and sample environments.
The ESS cryomodule test stand, together with a test stand at Uppsala University in Sweden, allow testing of all cryomodules containing RF cavities at full RF power and various operating temperatures (2 K, 4.2 K and 40 K) prior to installation in the linac tunnel.
The test and instruments cryoplant also provides liquid helium to other customers in the Lund region – specifically Lund University and the Max IV synchrotron facility. Funding and partnership The ESS is a pan-European project with 13 European nations as members: Czech Republic, Denmark, Estonia, France, Germany, Hungary, Italy, Norway, Poland, Spain, Sweden, Switzerland and the UK.
Significant in-kind contributions of equipment and expertise – from over 40 European partner laboratories – are expected to finance more than a third of the overall construction costs for ESS.
ESS will deliver its first science in 2023, with up to 3000 visiting researchers expected every year once the lab is fully operational.


physicsworld--2020-07-06--Advanced MRI methods guide treatments of tremor - Physics World

Researchers at the University of Texas Southwestern and the Mayo Clinic in the US have presented the latest developments in the use of MR-guided high-intensity focused ultrasound ( HIFU ) to treat tremor .
Writing in the journal Brain , they describe how these advances are expected to lead to improved clinical efficacy and a reduction of adverse effects .
The first-line treatment to reduce the involuntary trembling or shaking associated with neurologic conditions such as essential tremor or Parkinson ’ s disease is medication .
However , around 30 % of patients do not respond well to drugs .
@ @ @ @ @ @ @ therapies to alter the connectivity of the thalamus , a symmetric structure composed of grey matter that sits on top of the brain stem and serves as a relay for motor and sensory signals between the body and the rest of the brain .
In the 1990s , deep brain stimulation was developed , in which metal electrodes implanted in the thalamus were stimulated via a battery pack , similarly to a pacemaker .
A couple of decades later , advances in MRI allowed real-time guidance of HIFU beams to non-invasively heat and @ @ @ @ @ @ @ millimetre precision .
The main challenge in both of these procedures , however , lies in the correct targeting of the ventral intermediate ( VIM ) nucleus , a pea-sized region located at the centre of the thalamus that ’ s involved in the coordination and planning of movement .
Precise localization of this structure is important to prevent adverse effects due to incorrect targeting during these procedures , such as speech and swallowing deficits , or sensory and gait abnormalities .
While these side effects are usually temporary , they can be @ @ @ @ @ @ @ cases .
In their paper , Bhavya Shah and colleagues highlight the limitations of current techniques for localizing the VIM nucleus .
Established targeting methods either use atlases to identify brain areas from a collection of correctly labelled brain scans or require the use of landmarks on the patient ’ s brain scans .
We now know that such atlases and landmarks are too simplistic , and that the connections and biology of the brain are too complex and patient-specific to be accurately captured through these methods .
Indeed , studies have shown @ @ @ @ @ @ @ of up to 5 mm , causing unacceptable adverse effects .
In contrast with traditional localization techniques , the researchers highlight three newly refined MRI techniques that are proving better at delineating the target tissue .
Diffusion tractography seems to be the most promising .
It creates precise 3D brain images by taking into account the natural water movement within tissues , which allows identification of not only the VIM nucleus location but also its shape .
Another technique hailed as superior to established targeting methods is quantitative susceptibility mapping , which creates @ @ @ @ @ @ @ in the magnetic field caused by substances such as iron or myelin .
Finally , the researchers cite fast grey matter acquisition T1 inversion recovery as showing promising results .
This technique operates much like a photo negative , turning the brain ’ s white matter dark and its grey matter white , in order to provide greater detail in the grey matter .
All of these MRI sequences are already approved by the US Food and Drug Administration for guiding HIFU beams during localized ablation of the thalamus .
The object of @ @ @ @ @ @ @ should improve clinical efficacy and reduce adverse effects from the treatment .

Diffusion tractography, which uses the movement of water molecules to identify tracts that connect different parts of the brain, can pinpoint the part of the thalamus to treat with focused ultrasound. (Courtesy: UT Southwestern Medical Center)
Researchers at the University of Texas Southwestern and the Mayo Clinic in the US have presented the latest developments in the use of MR-guided high-intensity focused ultrasound (HIFU) to treat tremor. Writing in the journal Brain, they describe how these advances are expected to lead to improved clinical efficacy and a reduction of adverse effects.
The first-line treatment to reduce the involuntary trembling or shaking associated with neurologic conditions such as essential tremor or Parkinson’s disease is medication. However, around 30% of patients do not respond well to drugs. This led to the investigation of alternative therapies to alter the connectivity of the thalamus, a symmetric structure composed of grey matter that sits on top of the brain stem and serves as a relay for motor and sensory signals between the body and the rest of the brain.
In the 1990s, deep brain stimulation was developed, in which metal electrodes implanted in the thalamus were stimulated via a battery pack, similarly to a pacemaker. A couple of decades later, advances in MRI allowed real-time guidance of HIFU beams to non-invasively heat and eliminate small sections of the thalamus with millimetre precision.
The main challenge in both of these procedures, however, lies in the correct targeting of the ventral intermediate (VIM) nucleus, a pea-sized region located at the centre of the thalamus that’s involved in the coordination and planning of movement. Precise localization of this structure is important to prevent adverse effects due to incorrect targeting during these procedures, such as speech and swallowing deficits, or sensory and gait abnormalities. While these side effects are usually temporary, they can be permanent in 15 to 20% of cases.
First author Bhavya Shah.
In their paper, Bhavya Shah and colleagues highlight the limitations of current techniques for localizing the VIM nucleus. Established targeting methods either use atlases to identify brain areas from a collection of correctly labelled brain scans or require the use of landmarks on the patient’s brain scans.
We now know that such atlases and landmarks are too simplistic, and that the connections and biology of the brain are too complex and patient-specific to be accurately captured through these methods. Indeed, studies have shown that these approaches can introduce targeting errors of up to 5 mm, causing unacceptable adverse effects.
MRI methods to the rescue
In contrast with traditional localization techniques, the researchers highlight three newly refined MRI techniques that are proving better at delineating the target tissue.
Diffusion tractography seems to be the most promising. It creates precise 3D brain images by taking into account the natural water movement within tissues, which allows identification of not only the VIM nucleus location but also its shape.
Another technique hailed as superior to established targeting methods is quantitative susceptibility mapping, which creates contrast in the image by detecting distortion in the magnetic field caused by substances such as iron or myelin. Finally, the researchers cite fast grey matter acquisition T1 inversion recovery as showing promising results. This technique operates much like a photo negative, turning the brain’s white matter dark and its grey matter white, in order to provide greater detail in the grey matter.
All of these MRI sequences are already approved by the US Food and Drug Administration for guiding HIFU beams during localized ablation of the thalamus. The object of an increasing number of studies, they should improve clinical efficacy and reduce adverse effects from the treatment.


physicsworld--2020-07-04--Quantum dots help preserve historic limestone monuments - Physics World

From the Egyptian pyramids to The Pentagon in Washington DC , limestone has long been one of the most popular materials for ornate buildings and monuments .
But this rock ’ s aesthetic qualities and workability come at a price – it can be vulnerable to degradation by natural weathering , air pollution and other processes .
New research by scientists in Spain and Greece might provide a new way of preserving limestone architecture for future generations .
The group has created a nano-composite doped with quantum dots , which can be applied to reinforce limestone structures while providing a @ @ @ @ @ @ @ consolidating historic architecture , you want durability and chemical compatibility , without changing its aesthetic features .
Traditionally , limestones have been treated using limewater , a common name for a dilute aqueous solution of calcium hydroxide .
Limewater can create a durable seal , but it does not tend to penetrate deeply into the rock .
Also , calcium hydroxide has a limited solubility in water .
An alternative developed the past decade are “ nanolimes ” – calcium hydroxide nanoparticles dispersed in water or organic solvents .
The tiny size of @ @ @ @ @ @ @ stone , while the increased specific surface area can enhance the carbonation process .
Indeed , it is the calcium carbonate created in this process that cements the original limestone structure , not the nanoparticles themselves .
Nanolimes are still a relatively young technology so there is uncertainty over how they will perform over long time periods .
In some cases , nanoparticles have been known to migrate back to the surface as the solvent evaporates .
So , when applying nanolimes in the real world it is important to monitor their performance @ @ @ @ @ @ @ , a new type of nanolime has been created by a team led by Javier Becerra Luna from the Universidad Pablo de Olavide in Spain .
Dubbed “ Nanorepair UV ” , the material takes advantage of the optical properties of quantum dots .
These are tiny pieces of semiconductor just a few nanometres across that are sometimes described as “ artificial atoms ” because they absorb and emit light at specific wavelengths .
Becerra ’ s nanolime comprises calcium hydroxide nanoparticles doped with zinc oxide quantum dots , which act as markers @ @ @ @ @ @ @ the quantum dots emit fluorescent light , highlighting the newly formed limestone against the original structure .
In practice , conservation workers would remove a small sample from an inconspicuous part of a monument to establish how deeply the consolidant has penetrated and how it is performing .
“ The major technical challenge was creating a nanocomposite and not a mixture of two different nanoparticles .
It is a key point that the quantum dots are posed on the calcium hydroxide , so we can measure the real penetration depth of the treatment @ @ @ @ @ @ @ In the group ’ s latest study , the prototype product was tested against three commercially available consolidants .
Two of the alternatives are silica-based , while the other uses calcium hydroxide nanoparticles but without the quantum dots .
All four products were tested on samples from two separate quarries in the Cadiz province of southern Spain .
Limestones from these sites were used in the cathedrals of Seville and Cadiz and other important Spanish buildings .
Historically , limestone has been widely used throughout southern Europe and northern Africa due to the @ @ @ @ @ @ @ the Mediterranean Sea .
Describing their findings in Applied Clay Science , the researchers conclude that the two nanolime products had higher effectiveness and better durability than the silica treatments .
However , Nanorepair UV had the added advantage of the quantum dots .
Shining a UV light on rock cross sections revealed penetration depths of up to 0.8 cm .
Out in the real world , one of the biggest perils for limestone monuments is weathering by salt crystallization .
Water entering the pore network of a stone may contain salts in @ @ @ @ @ @ @ evaporates .
This creates pressure inside pores that can lead to micro-fractures , eventually compromising the rock ’ s surface structure .
In the study , treated samples were subjected to accelerated salt crystallization by being soaked in a sodium sulphate hydrate and baked in an oven multiple times .
Sample surfaces were then peeled using a standard sticky tape to reveal the extent to which they had been compromised .
The Nanorepair UV-treated sample fared better than the other nanolimes .
The team attributes this to the presence of silane in Nanorepair @ @ @ @ @ @ @ the quantum dots .
The results have impressed Roberta Fanatoni , an applied scientist at Italy ’ s National Agency for New Technologies , Energy and Sustainable Economic Development , who was not involved in the research .
“ A single product was able to overcome distinct limitations on limestones of the other three commercial products , ” she said .
Fanatoni also points out that the presence of zinc oxide might provide an additional benefit of acting as a biocide , reducing stone degradation due to biological processes .
According to Carlos @ @ @ @ @ @ @ s University of Granada , the Mediterranean basin is full of monuments build from very similar limestones .
“ You can see very nice examples of monuments built with calcarenite in Sicily , Puglia or the Greek Islands .
So , the potential applications of this novel treatments are likely limitless.
” A specialist in cultural heritage , Rodríguez-Navarro does caution , however , that the need to remove samples from historic stonework would be discouraged in lots of real-world situations .
He also points out that lab tests can never provide 100 @ @ @ @ @ @ @ behave in the real-world .
Becerra ’ s group has patented Nanorepair UV and they are currently looking for industrial partners to scale up production .
They are in the process of testing the nanolime on real samples of Roman mortars and they are also studying the use of nanoparticles for other cultural items including books and bones .

Testing time: Nanorepair UV being applied to limestone samples from Cadiz (Courtesy: Javier Becerra)
From the Egyptian pyramids to The Pentagon in Washington DC, limestone has long been one of the most popular materials for ornate buildings and monuments. But this rock’s aesthetic qualities and workability come at a price – it can be vulnerable to degradation by natural weathering, air pollution and other processes.
New research by scientists in Spain and Greece might provide a new way of preserving limestone architecture for future generations. The group has created a nano-composite doped with quantum dots, which can be applied to reinforce limestone structures while providing a way of monitoring the changes.
When consolidating historic architecture, you want durability and chemical compatibility, without changing its aesthetic features. Traditionally, limestones have been treated using limewater, a common name for a dilute aqueous solution of calcium hydroxide. Limewater can create a durable seal, but it does not tend to penetrate deeply into the rock. Also, calcium hydroxide has a limited solubility in water.
An alternative developed the past decade are “nanolimes” – calcium hydroxide nanoparticles dispersed in water or organic solvents. The tiny size of nanoparticles enables them to penetrate deeper into stone, while the increased specific surface area can enhance the carbonation process. Indeed, it is the calcium carbonate created in this process that cements the original limestone structure, not the nanoparticles themselves.
Nanolimes are still a relatively young technology so there is uncertainty over how they will perform over long time periods. In some cases, nanoparticles have been known to migrate back to the surface as the solvent evaporates. So, when applying nanolimes in the real world it is important to monitor their performance over time.
Nanolimes with a twist of quantum dots
To help with monitoring, a new type of nanolime has been created by a team led by Javier Becerra Luna from the Universidad Pablo de Olavide in Spain. Dubbed “Nanorepair UV”, the material takes advantage of the optical properties of quantum dots. These are tiny pieces of semiconductor just a few nanometres across that are sometimes described as “artificial atoms” because they absorb and emit light at specific wavelengths.
Becerra’s nanolime comprises calcium hydroxide nanoparticles doped with zinc oxide quantum dots, which act as markers. When illuminated with UV light, the quantum dots emit fluorescent light, highlighting the newly formed limestone against the original structure. In practice, conservation workers would remove a small sample from an inconspicuous part of a monument to establish how deeply the consolidant has penetrated and how it is performing.
“The major technical challenge was creating a nanocomposite and not a mixture of two different nanoparticles. It is a key point that the quantum dots are posed on the calcium hydroxide, so we can measure the real penetration depth of the treatment,” Becerra told Physics World.
From left to right: calcium hydroxide nanoparticles doped with zinc oxide quantum dots; UV light detecting treatment penetration; Seville City Hall (Courtesy: José María Martín/Javier Becerra)
In the group’s latest study, the prototype product was tested against three commercially available consolidants. Two of the alternatives are silica-based, while the other uses calcium hydroxide nanoparticles but without the quantum dots.
All four products were tested on samples from two separate quarries in the Cadiz province of southern Spain. Limestones from these sites were used in the cathedrals of Seville and Cadiz and other important Spanish buildings. Historically, limestone has been widely used throughout southern Europe and northern Africa due to the large amount of calcareous geology found around the Mediterranean Sea.
Describing their findings in Applied Clay Science, the researchers conclude that the two nanolime products had higher effectiveness and better durability than the silica treatments. However, Nanorepair UV had the added advantage of the quantum dots. Shining a UV light on rock cross sections revealed penetration depths of up to 0.8 cm.
A dash of salt
Out in the real world, one of the biggest perils for limestone monuments is weathering by salt crystallization. Water entering the pore network of a stone may contain salts in solution, which can crystallize as water evaporates. This creates pressure inside pores that can lead to micro-fractures, eventually compromising the rock’s surface structure.
In the study, treated samples were subjected to accelerated salt crystallization by being soaked in a sodium sulphate hydrate and baked in an oven multiple times. Sample surfaces were then peeled using a standard sticky tape to reveal the extent to which they had been compromised. The Nanorepair UV-treated sample fared better than the other nanolimes. The team attributes this to the presence of silane in Nanorepair UV, which is included to stabilize the quantum dots.
The results have impressed Roberta Fanatoni, an applied scientist at Italy’s National Agency for New Technologies, Energy and Sustainable Economic Development, who was not involved in the research. “A single product was able to overcome distinct limitations on limestones of the other three commercial products,” she said.
Fanatoni also points out that the presence of zinc oxide might provide an additional benefit of acting as a biocide, reducing stone degradation due to biological processes.
According to Carlos Rodríguez-Navarro, a geologist at Spain’s University of Granada, the Mediterranean basin is full of monuments build from very similar limestones. “You can see very nice examples of monuments built with calcarenite in Sicily, Puglia or the Greek Islands. So, the potential applications of this novel treatments are likely limitless.”
A specialist in cultural heritage, Rodríguez-Navarro does caution, however, that the need to remove samples from historic stonework would be discouraged in lots of real-world situations. He also points out that lab tests can never provide 100% guarantee of how a treatment will behave in the real-world.
Becerra’s group has patented Nanorepair UV and they are currently looking for industrial partners to scale up production. They are in the process of testing the nanolime on real samples of Roman mortars and they are also studying the use of nanoparticles for other cultural items including books and bones.


physicsworld--2020-07-03--The physics of N95 masks, imaging sensitive corals, how Fermilab’s PIP-II accelerator will work - Ph

The physics of N95 masks, imaging sensitive corals, how Fermilab’s PIP-II accelerator will work - Physics World

N95 masks are much more than a simple screen filter and use lots of interesting physics – including van der Waals forces – to stop you from breathing in nasty virus particles .
The above video does a superb job of explaining how the masks work and also touches on efforts to make them reusable .
Some corals are very sensitive to light , which makes it tricky to obtain high quality images of the organisms .
Now , Philippe Laissue at the UK ’ s University of Essex and the Marine Biological Laboratory ( MBL ) in Woods Hole @ @ @ @ @ @ @ light-sheet microscope that allows the gentle and non-invasive observation of corals and their polyps over eight hours and at high resolution .
They used their microscope to obtain this stunning image ( left ) , which shows the re-infection of an Astrangia coral polyp ( in cyan from reflected light ) with algae ( red from chlorophyll fluorescence ) .
The researchers , including MBL ’ s Loretta Roberson , describe the technique in Scientific Reports .
PIP-II at Fermilab will be the first accelerator built in the US with significant contributions from @ @ @ @ @ @ @ , UK , France and Poland building major components .
Described as the new heart of Fermilab , PIP-II will be an 800 MeV superconducting linear accelerator that delivers a high-intensity proton beam .
It can operate in both steady-state and pulsed mode and some of its protons will be used to create an intense beam of neutrinos that will travel 1300 km underground to a detector in South Dakota .
The video below describes how PIP-II will accelerate protons .

N95 masks are much more than a simple screen filter and use lots of interesting physics – including van der Waals forces – to stop you from breathing in nasty virus particles. The above video does a superb job of explaining how the masks work and also touches on efforts to make them reusable.
Some corals are very sensitive to light, which makes it tricky to obtain high quality images of the organisms. Now, Philippe Laissue at the UK’s University of Essex and the Marine Biological Laboratory (MBL) in Woods Hole Massachusetts and colleagues have created a custom light-sheet microscope that allows the gentle and non-invasive observation of corals and their polyps over eight hours and at high resolution.
Coral see: image of a coral polyp (in cyan from reflected light) with algae (red from chlorophyll fluorescence). (Courtesy: Loretta Roberson)
They used their microscope to obtain this stunning image (left), which shows the re-infection of an Astrangia coral polyp (in cyan from reflected light) with algae (red from chlorophyll fluorescence).
The researchers, including MBL’s Loretta Roberson, describe the technique in Scientific Reports.
PIP-II at Fermilab will be the first accelerator built in the US with significant contributions from other countries — with India, Italy, UK, France and Poland building major components.
Described as the new heart of Fermilab, PIP-II will be an 800 MeV superconducting linear accelerator that delivers a high-intensity proton beam. It can operate in both steady-state and pulsed mode and some of its protons will be used to create an intense beam of neutrinos that will travel 1300 km underground to a detector in South Dakota. The video below describes how PIP-II will accelerate protons.


physicsworld--2020-07-03--Light-activated catalysts make nearly perfect water-splitters - Physics World

Using sunlight to decompose water could be a clean and renewable way to produce hydrogen fuel , but the photocatalysts traditionally used to promote the process are relatively inefficient .
Researchers in Japan have now developed a model system based on strontium titanate that has an external quantum efficiency of 96 % , proving that almost perfectly efficient catalysts are possible .
Because the combustion of hydrogen yields only pure water as a waste product , it is often touted as an environmentally-friendly alternative to fossil fuels .
The caveat is that to be truly “ green ” , the @ @ @ @ @ @ @ renewable energy .
Solar water splitting , in which sunlight is directed onto an aqueous suspension of light-activated semiconducting particles , is one way of cleanly producing hydrogen .
When these particles absorb solar photons , the resulting electron-hole pairs catalyze the breakdown of water , liberating the hydrogen .
The drawback of this method is that the catalytic process is highly complex , requiring the semiconductor particles to play several roles at once .
First , they must be able to absorb light in the solar spectrum range , which means they @ @ @ @ @ @ @ 500nm peak of the Sun ’ s emissions .
Second , they need to generate and then separate electron-hole pairs .
Third , they must allow these holes and electrons to travel to the particle-water interface and catalyse the production of hydrogen ( a process that requires electrons ) and oxygen ( a process that requires holes ) from water .
Last , but not least , they need to minimize unwanted side processes ( which can lower the overall efficiency of the system ) occurring at each step along the way .
@ @ @ @ @ @ @ although researchers have long been searching for efficient photocatalytic materials , typical photocatalysts have an external quantum efficiency ( EQE ) – that is , the fraction of photons impinging on the system that end up being used to produce hydrogen – of less than 10 % .
In their work , a team of researchers led by Kazunari Domen of Shinshu University in Nagano and the University of Tokyo focused on strontium titanate ( SrTiO ) , a photocatalytic water-splitter that was discovered in the 1970s .
Although SrTiO is impractical for @ @ @ @ @ @ @ pairs by absorbing near-ultraviolet light rather than visible light ) , the researchers argue that it is nevertheless a good model system because the mechanisms responsible for its efficiency losses are well understood .
Domen and colleagues studied several ways of reducing loss mechanisms in SrTiO .
The first involved suppressing charge carrier recombination , which occurs when electrons and holes recombine before they can take part in the water-splitting reaction .
Since defects in the crystal lattice act as potential recombination hubs , the researchers used a flux treatment to improve the @ @ @ @ @ @ @ reducing the number of lattice defects .
They then reduced the number of chemical defects in the lattice by aluminium doping .
The team ’ s second strategy was to further suppress charge recombination by taking advantage of the fact that electron and holes in SrTiO crystals collect at different crystal facets .
They did this by selectively depositing specific co-catalysts on the different facets to enhance hydrogen production at the electron-collecting facets and oxygen production at the hole-collecting ones .
Although this approach is not new , and was developed and refined @ @ @ @ @ @ @ Physics World that in the present work , his team was able to demonstrate the approach ’ s effectiveness “ more clearly than any former study ” .
Finally , the researchers prevented an unwanted side reaction ( the oxygen-reduction reaction ) by encasing the rhodium co-catalysts for the hydrogen-producing reaction in a chromium-based protective shell .
By combining these three strategies , the team demonstrated an EQE of up to 96 % for their material when it was irradiated with light in the 350-360 nm range .
This translates into an internal @ @ @ @ @ @ @ is the fraction of absorbed photons that can be used to produce hydrogen , of near unity , which implies that the photocatalyst is almost perfect .
Domen and colleagues hope their strategies to improve the efficiency of SrTiO will also work for photocatalysts driven by visible light .
They have published their results in Nature and Simone Pokrant of the University of Salzburg in Austria , who was not involved in this work , details their findings and their implications in a related Nature News and Views article .

Kazunari Domen. Courtesy: Shinshu University
Using sunlight to decompose water could be a clean and renewable way to produce hydrogen fuel, but the photocatalysts traditionally used to promote the process are relatively inefficient. Researchers in Japan have now developed a model system based on strontium titanate that has an external quantum efficiency of 96%, proving that almost perfectly efficient catalysts are possible.
Because the combustion of hydrogen yields only pure water as a waste product, it is often touted as an environmentally-friendly alternative to fossil fuels. The caveat is that to be truly “green”, the hydrogen itself needs to be produced using renewable energy. Solar water splitting, in which sunlight is directed onto an aqueous suspension of light-activated semiconducting particles, is one way of cleanly producing hydrogen. When these particles absorb solar photons, the resulting electron-hole pairs catalyze the breakdown of water, liberating the hydrogen.
Several roles
The drawback of this method is that the catalytic process is highly complex, requiring the semiconductor particles to play several roles at once. First, they must be able to absorb light in the solar spectrum range, which means they need to have narrow bandgaps near the 500nm peak of the Sun’s emissions. Second, they need to generate and then separate electron-hole pairs. Third, they must allow these holes and electrons to travel to the particle-water interface and catalyse the production of hydrogen (a process that requires electrons) and oxygen (a process that requires holes) from water. Last, but not least, they need to minimize unwanted side processes (which can lower the overall efficiency of the system) occurring at each step along the way.
That is a long list, and although researchers have long been searching for efficient photocatalytic materials, typical photocatalysts have an external quantum efficiency (EQE) – that is, the fraction of photons impinging on the system that end up being used to produce hydrogen – of less than 10%.
Strategies for reducing loss mechanisms
In their work, a team of researchers led by Kazunari Domen of Shinshu University in Nagano and the University of Tokyo focused on strontium titanate (SrTiO 3 ), a photocatalytic water-splitter that was discovered in the 1970s. Although SrTiO 3 is impractical for making real-world photocatalysts (it produces electron-hole pairs by absorbing near-ultraviolet light rather than visible light), the researchers argue that it is nevertheless a good model system because the mechanisms responsible for its efficiency losses are well understood.
Domen and colleagues studied several ways of reducing loss mechanisms in SrTiO 3 . The first involved suppressing charge carrier recombination, which occurs when electrons and holes recombine before they can take part in the water-splitting reaction. Since defects in the crystal lattice act as potential recombination hubs, the researchers used a flux treatment to improve the crystallinity of the photocatalyst particles, thereby reducing the number of lattice defects. They then reduced the number of chemical defects in the lattice by aluminium doping.
The team’s second strategy was to further suppress charge recombination by taking advantage of the fact that electron and holes in SrTiO 3 crystals collect at different crystal facets. They did this by selectively depositing specific co-catalysts on the different facets to enhance hydrogen production at the electron-collecting facets and oxygen production at the hole-collecting ones. Although this approach is not new, and was developed and refined by other research groups, Domen tells Physics World that in the present work, his team was able to demonstrate the approach’s effectiveness “more clearly than any former study”.
Finally, the researchers prevented an unwanted side reaction (the oxygen-reduction reaction) by encasing the rhodium co-catalysts for the hydrogen-producing reaction in a chromium-based protective shell.
Near-unity internal quantum efficiency
By combining these three strategies, the team demonstrated an EQE of up to 96% for their material when it was irradiated with light in the 350-360 nm range. This translates into an internal quantum efficiency (IQE), which is the fraction of absorbed photons that can be used to produce hydrogen, of near unity, which implies that the photocatalyst is almost perfect.
Domen and colleagues hope their strategies to improve the efficiency of SrTiO 3 will also work for photocatalysts driven by visible light. They have published their results in Nature and Simone Pokrant of the University of Salzburg in Austria, who was not involved in this work, details their findings and their implications in a related Nature News and Views article.


physicsworld--2020-07-03--From virus spikes to narwhal tusks, physicists discover universal design for stingers - Physics Worl

From virus spikes to narwhal tusks, physicists discover universal design for stingers - Physics World

From virus spikes to narwhal tusks , the stingers of many living organisms have the same basic mechanical design .
Now a team of physicists led by Kaare Jensen has studied the mechanical properties of more than 200 natural and manmade stingers to discover why .
The researchers at the Technical University of Denmark found a clear relationship between the structural properties of stingers large and small – thereby solving a long-standing evolutionary mystery .
As a bonus , their work could lead to artificial structures that better mimic the desirable properties of natural stingers .
A staggering variety of @ @ @ @ @ @ @ for purposes ranging from catching prey to combating rivals .
These stingers range in size from tens of nanometres to several metres , yet are remarkably similar in terms of their design and mechanical properties – even in very different organisms .
This similarity also extends to artificial structures such as nails and pointed weapons .
To understand this ubiquity of design , Jensen ’ s team experimented with artificial stingers made from the polymer polydimethylsiloxane and compared their results with previous studies of natural stingers .
For simplicity , the team define @ @ @ @ @ @ @ with a long , slender tapered shape and a roughly circular cross-section .
Their definition also includes strong resistance to elastic deformation .
Within these constraints , they constructed a database of stingers from over 200 objects , including viruses , algae , and larger vertebrates and invertebrates : both marine and terrestrial .
They also included manmade objects such as nails used in construction , hypodermic needles , and spears from ancient warfare .
The experiments revealed how stingers buckled and broke when subjected to a load .
When combined with the @ @ @ @ @ @ @ scientific literature , these data revealed an optimal relationship between the diameters , lengths , stiffnesses , and friction forces per unit area of different stingers .
A crucial insight revealed by the study is that stinger structures exist at the mechanical limits imposed by friction , elastic stability , and costs incurred by maintaining tissue .
This constraint ultimately explains the universality found in stinger structures : no matter their size , living organisms evolve until their outgrowths reach these limits , causing their stingers to converge at the same shape .
@ @ @ @ @ @ @ ’ s team will now explore how their findings could apply to biomechanics and the evolution of animal weapons , and potentially lead to new medical applications .
Elsewhere , they could inform engineers as to how manmade structures which mimic natural stingers could be precisely manufactured on different scales to improve performance and reduce material costs .
The research is described in Nature Physics .

Universal stingers: this plant has something in common with a swordfish. (Courtesy: Kaare Jensen/Technical University of Denmark)
From virus spikes to narwhal tusks, the stingers of many living organisms have the same basic mechanical design. Now a team of physicists led by Kaare Jensen has studied the mechanical properties of more than 200 natural and manmade stingers to discover why.
The researchers at the Technical University of Denmark found a clear relationship between the structural properties of stingers large and small – thereby solving a long-standing evolutionary mystery. As a bonus, their work could lead to artificial structures that better mimic the desirable properties of natural stingers.
A staggering variety of living organisms come equipped with pointed outgrowths for purposes ranging from catching prey to combating rivals. These stingers range in size from tens of nanometres to several metres, yet are remarkably similar in terms of their design and mechanical properties – even in very different organisms. This similarity also extends to artificial structures such as nails and pointed weapons.
Resistance to elastic deformation
To understand this ubiquity of design, Jensen’s team experimented with artificial stingers made from the polymer polydimethylsiloxane and compared their results with previous studies of natural stingers. For simplicity, the team define a stinger as being straight and rigid with a long, slender tapered shape and a roughly circular cross-section. Their definition also includes strong resistance to elastic deformation.
Within these constraints, they constructed a database of stingers from over 200 objects, including viruses, algae, and larger vertebrates and invertebrates: both marine and terrestrial. They also included manmade objects such as nails used in construction, hypodermic needles, and spears from ancient warfare.
The experiments revealed how stingers buckled and broke when subjected to a load. When combined with the results of previous studies described in the scientific literature, these data revealed an optimal relationship between the diameters, lengths, stiffnesses, and friction forces per unit area of different stingers.
A crucial insight revealed by the study is that stinger structures exist at the mechanical limits imposed by friction, elastic stability, and costs incurred by maintaining tissue. This constraint ultimately explains the universality found in stinger structures: no matter their size, living organisms evolve until their outgrowths reach these limits, causing their stingers to converge at the same shape.
Having explained this long-standing mystery, Jensen’s team will now explore how their findings could apply to biomechanics and the evolution of animal weapons, and potentially lead to new medical applications. Elsewhere, they could inform engineers as to how manmade structures which mimic natural stingers could be precisely manufactured on different scales to improve performance and reduce material costs.
The research is described in Nature Physics.


physicsworld--2020-07-03--Bipartisan bill aims to revamp National Science Foundation - Physics World

A bipartisan group of US senators and representatives has introduced legislation in Congress that would significantly change the operation of the National Science Foundation ( NSF ) .
Proponents of the bill say that the proposal aims “ to solidify the United States ’ leadership in scientific and technological innovation through increased investments in the discovery , creation , and commercialization of technology fields of the future ” .
To do so , the so-called Endless Frontier Act would expand the NSF ’ s remit , rename the organization and provide more than $ 100bn in support .
The proposal @ @ @ @ @ @ @ some have objected that it may undercut the NSF ’ s main objective , which is to fund basic scientific research .
Those behind the bill – four prominent US congresspeople – say that its introduction stems from the perception that international competitors , and particularly China , threaten to overtake the US technologically .
“ To win the 21st century , we need to invest in technologies of the future , ” says Ro Kahana , a Democratic congressperson from California .
“ That means increasing public funding into those sectors of @ @ @ @ @ @ @ create new jobs.
” Chuck Schumer , a New Yorker who leads the Democratic minority in the Senate , says that the US “ can not afford ” to continue to underinvest in science while still “ lead [ ing ] the world ” in advanced research .
That view is backed by Republican senator Todd Young of Indiana .
“ By virtue of being the first to emerge on the other side of this pandemic , the Chinese Communist Party is working hard to use the crisis to its advantage by extending @ @ @ @ @ @ @ he claims .
The new act , adds Republican representative Mike Gallagher of Wisconsin , who is the fourth member of the group introducing the legislation , “ is a down payment for future generations of American technological leadership ” .
The group announced the bill shortly after the 70th birthday of the NSF on 10 May .
The legislation is named after a report – Science : the Endless Frontier – by Vannevar Bush , who was at the time director of the US government ’ s Office of Scientific Research and @ @ @ @ @ @ @ years ago on 5 July , laid the foundations for the US ’ s postwar boom in science and technology .
The changes envisioned by the group start with the name .
The NSF would become the National Science and Technology Foundation ( NTSF ) , with the additional “ T ” creating a new technology directorate – with its own deputy director – that has “ flexible personnel , programme management , and awarding authorities ” .
The new directorate would fund research in 10 specific areas including : artificial intelligence and @ @ @ @ @ @ @ , and advanced computer hardware ; quantum computing and information systems ; robotics , automation and advanced manufacturing ; and advanced energy technology .
The transformation , however , would not come cheap , costing $ 100bn over five years .
The bill authorizes an extra $ 10bn over five years to enable the Department of Commerce – another science-related government agency – to designate at least 10 regional hubs across the country .
These would act as global centres for research , development and manufacturing of key technologies .
That amount would @ @ @ @ @ @ @ They include increased research spending at universities , which could form consortia with private industry to create focused research centres and develop other ways to advance new technologies .
It would also include programmes to facilitate and accelerate the transfer of new technologies from the laboratory to the market as well as increased spending on research collaborations with US partners .
Leaders of research institutions have shown their enthusiasm for the bill .
“ To maintain global competitiveness and nurture future job creation , our country must prioritize research that will be fundamental @ @ @ @ @ @ @ New York University president Andrew Hamilton .
Rafael Reif , president of the Massachusetts Institute of Technology , agrees .
“ Supporting fundamental research with an eye to real-world challenges is the kind of thinking that drove the Defense Advanced Research Projects Agency to develop what became the Internet , ” he wrote in The Hill .
“ Such use-inspired basic research , funded by NSF…is what ’ s needed to retain US leadership in both science and technology , to keep us prosperous and secure.
” Yet the proposal has drawn some @ @ @ @ @ @ @ told Science of his concern that the bill could indicate to Congress – which appropriates agencies ’ funds – that investments in the bill ’ s innovative technologies override the importance of the NSF ’ s core mission of funding fundamental , curiosity-driven research .
But Bement ’ s successor France Córdova , who completed her six-year term as NSF director in March , argues that current-day science involves more seamless integration between fundamental and applied research .
The relevant committees of the House of Representatives and the Senate have yet to schedule @ @ @ @ @ @ @ impact of coronavirus and protests from the Black Lives Matter movement as well as the forthcoming presidential election in November , an early decision on the legislation looks unlikely .
Nevertheless , the bipartisan group that promotes the legislation has given legislators and the US scientific community indications of a new approach to the relationship between government-funded research and application .

Physics World. Members of the Institute of Physics can enjoy the full issue Taken from the July 2020 issue of. Members of the Institute of Physics can enjoy the full issue via the Physics World app
Lawmakers are seeking to change the remit of the National Science Foundation so that it focuses more on the commercialization of research, as Peter Gwynne reports
Changes ahead The “Endless Frontier Act” would fund the National Science Foundation with $100bn to expand its remit. (Courtesy: Shutterstock/JHVEPhoto)
A bipartisan group of US senators and representatives has introduced legislation in Congress that would significantly change the operation of the National Science Foundation (NSF). Proponents of the bill say that the proposal aims “to solidify the United States’ leadership in scientific and technological innovation through increased investments in the discovery, creation, and commercialization of technology fields of the future”. To do so, the so-called Endless Frontier Act would expand the NSF’s remit, rename the organization and provide more than $100bn in support. The proposal has gained approval from many, but some have objected that it may undercut the NSF’s main objective, which is to fund basic scientific research.
Those behind the bill – four prominent US congresspeople – say that its introduction stems from the perception that international competitors, and particularly China, threaten to overtake the US technologically. “To win the 21st century, we need to invest in technologies of the future,” says Ro Kahana, a Democratic congressperson from California. “That means increasing public funding into those sectors of our economy that will drive innovation and create new jobs.”
Chuck Schumer, a New Yorker who leads the Democratic minority in the Senate, says that the US “cannot afford” to continue to underinvest in science while still “lead[ing] the world” in advanced research. That view is backed by Republican senator Todd Young of Indiana. “By virtue of being the first to emerge on the other side of this pandemic, the Chinese Communist Party is working hard to use the crisis to its advantage by extending influence over the global economy,” he claims. The new act, adds Republican representative Mike Gallagher of Wisconsin, who is the fourth member of the group introducing the legislation, “is a down payment for future generations of American technological leadership”.
The group announced the bill shortly after the 70th birthday of the NSF on 10 May. The legislation is named after a report – Science: the Endless Frontier – by Vannevar Bush, who was at the time director of the US government’s Office of Scientific Research and Development. That report, published 75 years ago on 5 July, laid the foundations for the US’s postwar boom in science and technology.
Ringing the changes
The changes envisioned by the group start with the name. The NSF would become the National Science and Technology Foundation (NTSF), with the additional “T” creating a new technology directorate – with its own deputy director – that has “flexible personnel, programme management, and awarding authorities”. The new directorate would fund research in 10 specific areas including: artificial intelligence and machine learning; high-performance computing, semiconductors, and advanced computer hardware; quantum computing and information systems; robotics, automation and advanced manufacturing; and advanced energy technology.
The transformation, however, would not come cheap, costing $100bn over five years. The bill authorizes an extra $10bn over five years to enable the Department of Commerce – another science-related government agency – to designate at least 10 regional hubs across the country. These would act as global centres for research, development and manufacturing of key technologies. That amount would finance a series of authorized activities. They include increased research spending at universities, which could form consortia with private industry to create focused research centres and develop other ways to advance new technologies. It would also include programmes to facilitate and accelerate the transfer of new technologies from the laboratory to the market as well as increased spending on research collaborations with US partners.
Leaders of research institutions have shown their enthusiasm for the bill. “To maintain global competitiveness and nurture future job creation, our country must prioritize research that will be fundamental to innovation and discovery,” says New York University president Andrew Hamilton.
Rafael Reif, president of the Massachusetts Institute of Technology, agrees. “Supporting fundamental research with an eye to real-world challenges is the kind of thinking that drove the Defense Advanced Research Projects Agency to develop what became the Internet,” he wrote in The Hill. “Such use-inspired basic research, funded by NSF…is what’s needed to retain US leadership in both science and technology, to keep us prosperous and secure.”
Yet the proposal has drawn some criticism. Former NSF director Arden Bement told Science of his concern that the bill could indicate to Congress – which appropriates agencies’ funds – that investments in the bill’s innovative technologies override the importance of the NSF’s core mission of funding fundamental, curiosity-driven research. But Bement’s successor France Córdova, who completed her six-year term as NSF director in March, argues that current-day science involves more seamless integration between fundamental and applied research.
The relevant committees of the House of Representatives and the Senate have yet to schedule hearings on the bill. Given the impact of coronavirus and protests from the Black Lives Matter movement as well as the forthcoming presidential election in November, an early decision on the legislation looks unlikely. Nevertheless, the bipartisan group that promotes the legislation has given legislators and the US scientific community indications of a new approach to the relationship between government-funded research and application.


physicsworld--2020-07-03--‘Multifaceted radiomics’ predicts cancer metastasis risk - Physics World

An improved data-mining technique combines information from multiple imaging modalities and other clinical parameters to predict the risk of cancer metastasis .
In the new approach , imaging data from cancer patients are fed into a deep neural network whose output is processed by three different classification algorithms .
A novel way of fusing the results from the three classifiers then yields a prediction of whether , by the time of a follow-up consultation months or years later , the cancers will have spread .
The US-based researchers who developed the method demonstrated its effectiveness using diagnostic and treatment-planning images @ @ @ @ @ @ @ .
As with cancers elsewhere in the body , early-stage cancers of the head and neck are treated using radiotherapy , with increasing success .
When treatment fails , it is often down to the growth of new tumours far from the site of the initial disease .
Predicting which patients are most likely to develop distant metastasis ( DM ) is vital , so that low-risk patients can be spared the severe side effects that accompany the systemic treatments used to control cancer proliferation .
One method of categorizing patients in this @ @ @ @ @ @ @ from large imaging datasets — an approach known as “ radiomics.
” But while this technique has been shown to make good use of quantitative features found in single-modality datasets ( see CT-based radiomics reveals prostate cancer risk ) , multi-modality datasets have not yet been used to their best advantage , due to the relatively simple way that disparate features from each image type are combined .
Now , writing in Physics in Medicine and Biology , Zhiguo Zhou at UT Southwestern Medical Center and University of Central Missouri and colleagues describe @ @ @ @ @ @ @ radiomics ( M-radiomics ) – that makes more effective use of a dataset comprising positron-emission tomography ( PET ) and X-ray CT images .
The team compiled PET and CT images of 188 head-and-neck cancer patients who had follow-up consultations between six and 112 months after scanning .
The images , which were acquired at various institutions , had already been studied by physicians , and 257 features – such as textural and geometrical characteristics – had been extracted for each patient .
Also included in the dataset were other clinical parameters such @ @ @ @ @ @ @ the extent to which the disease had already progressed at the time of imaging .
Zhou and colleagues inputted a subset of these data points into a deep neural network , which fused them into a single feature set .
They then used this combined feature set to train a predictive model that could be tuned to optimize both sensitivity ( the likelihood of making a true positive prediction of DM ) and specificity ( the likelihood of making a true false prediction of DM ) simultaneously depending on clinical need .
Usually @ @ @ @ @ @ @ be sorted by a single classification algorithm to predict outcome : DM or no DM .
The researchers note that combining three different classification algorithms improves the reliability of their approach .
Tested against a separate subset of patient data , the researchers found that their M-radiomics approach outperformed versions of the technique that lacked either the deep neural network , sensitivity–specificity optimization , or classifier-combination steps .
They think that the method could be improved further by including image features outside of the physician-delineated tumour boundaries , and by developing a standardized @ @ @ @ @ @ @ between images captured at different institutions .
Zhou and colleagues plan to validate their method with a multi-institutional prospective study – in contrast to the retrospective dataset that they used for their demonstration – which should show its value for aiding clinical decision making in similar high-risk head-and-neck cancer patients .
“ Once validated , we hope clinical adoption of the model can be realized in two to three years , ” says Zhou ’ s co-author , Jing Wang , at UT Southwestern Medical Center .
As M-radiomics is a generalized framework @ @ @ @ @ @ @ to predict treatment outcomes for primary cancers in other anatomical sites .

An X-ray CT image (left) and a PET image (right) of a head-and-neck cancer patient. (Courtesy: Journal of Digital Imaging 10.1007/s10278-013-9622-7)
An improved data-mining technique combines information from multiple imaging modalities and other clinical parameters to predict the risk of cancer metastasis. In the new approach, imaging data from cancer patients are fed into a deep neural network whose output is processed by three different classification algorithms. A novel way of fusing the results from the three classifiers then yields a prediction of whether, by the time of a follow-up consultation months or years later, the cancers will have spread. The US-based researchers who developed the method demonstrated its effectiveness using diagnostic and treatment-planning images acquired for 188 patients with head-and-neck cancer.
As with cancers elsewhere in the body, early-stage cancers of the head and neck are treated using radiotherapy, with increasing success. When treatment fails, it is often down to the growth of new tumours far from the site of the initial disease. Predicting which patients are most likely to develop distant metastasis (DM) is vital, so that low-risk patients can be spared the severe side effects that accompany the systemic treatments used to control cancer proliferation.
One method of categorizing patients in this way is by extracting DM risk indicators from large imaging datasets — an approach known as “radiomics.” But while this technique has been shown to make good use of quantitative features found in single-modality datasets (see CT-based radiomics reveals prostate cancer risk), multi-modality datasets have not yet been used to their best advantage, due to the relatively simple way that disparate features from each image type are combined.
Now, writing in Physics in Medicine and Biology, Zhiguo Zhou at UT Southwestern Medical Center and University of Central Missouri and colleagues describe a technique – which they call multifaceted radiomics (M-radiomics) – that makes more effective use of a dataset comprising positron-emission tomography (PET) and X-ray CT images.
The team compiled PET and CT images of 188 head-and-neck cancer patients who had follow-up consultations between six and 112 months after scanning. The images, which were acquired at various institutions, had already been studied by physicians, and 257 features – such as textural and geometrical characteristics – had been extracted for each patient. Also included in the dataset were other clinical parameters such as patient age and gender, and the extent to which the disease had already progressed at the time of imaging.
Zhou and colleagues inputted a subset of these data points into a deep neural network, which fused them into a single feature set. They then used this combined feature set to train a predictive model that could be tuned to optimize both sensitivity (the likelihood of making a true positive prediction of DM) and specificity (the likelihood of making a true false prediction of DM) simultaneously depending on clinical need. Usually, the outputs of this model would be sorted by a single classification algorithm to predict outcome: DM or no DM. The researchers note that combining three different classification algorithms improves the reliability of their approach.
Tested against a separate subset of patient data, the researchers found that their M-radiomics approach outperformed versions of the technique that lacked either the deep neural network, sensitivity–specificity optimization, or classifier-combination steps. They think that the method could be improved further by including image features outside of the physician-delineated tumour boundaries, and by developing a standardized, automatic feature-extraction procedure to minimize variability between images captured at different institutions.
Zhiguo Zhou (left) and Jing Wang. (Courtesy: University of Central Missouri/UT Southwestern Medical Center)
Zhou and colleagues plan to validate their method with a multi-institutional prospective study – in contrast to the retrospective dataset that they used for their demonstration – which should show its value for aiding clinical decision making in similar high-risk head-and-neck cancer patients.
“Once validated, we hope clinical adoption of the model can be realized in two to three years,” says Zhou’s co-author, Jing Wang, at UT Southwestern Medical Center. As M-radiomics is a generalized framework, the approach could also be extended to predict treatment outcomes for primary cancers in other anatomical sites.


physicsworld--2020-07-02--The emotions of discovery, the quantum TV thriller Devs, nanosponges take on COVID-19 - Physics Worl

The emotions of discovery, the quantum TV thriller Devs, nanosponges take on COVID-19 - Physics World

In this episode of the Physics World Weekly podcast the philosopher of science Bob Crease chats about how physicists react @ @ @ @ @ new – the topic of his latest column in Physics World : “ The feelings @ @ @ @ @ something new ” .
Murder and the interpretations of quantum mechanics feature highly in the @ @ @ @ @ Devs , which is set on the campus of a fictitious quantum computer company in @ @ @ @ @ Phil Ball joins Physics World editors for a lively discussion about how quantum physics is @ @ @ @ @ it works as a physics thriller .
One way of treating people with COVID-19 is @ @ @ @ @ attacking healthy cells .
We chat about how researchers in the US are developing nanosponges @ @ @ @ @ up virus particles .

In this episode of the Physics World Weekly podcast the philosopher of science Bob Crease chats about how physicists react when they have discovered something new – the topic of his latest column in Physics World: “The feelings you get when you discover something new”.
Murder and the interpretations of quantum mechanics feature highly in the plot of the television series Devs, which is set on the campus of a fictitious quantum computer company in Silicon Valley. Science writer Phil Ball joins Physics World editors for a lively discussion about how quantum physics is portrayed in Devs and whether it works as a physics thriller.
One way of treating people with COVID-19 is to prevent the virus from attacking healthy cells. We chat about how researchers in the US are developing nanosponges that do this by soaking up virus particles.


physicsworld--2020-07-02--How lasers make the difference in MRI in RT – MRI solutions from LAP - Physics World

There have been enormous improvements in MRI over the last 20 years .
MR-only workflows and the invention of MR-guided linacs brought new perspectives into radiation therapy .
Are lasers still important for the alignment of patients on MRI ?
What kind of different workflows are currently practised in RT ?
The webinar presented by Raphael Schmidt and Michael Uhr will help the audience to : • Learn more about workflows in MR • Get to know the relevance of lasers for patient alignment • Get an overview on different solutions for MRI and MR-linac Raphael Schmidt is responsible for @ @ @ @ @ @ @ CT and MRI from LAP .
During his studies at the Karlsruhe Institute of Technology ( KIT ) he gained broad experience in different workflows in radiation therapy while analyzing them .
The topic of his final thesis dealt with the improvement of workflows in RT trough new information and assistance systems .
Schmidt holds a degree in industrial engineering and management .
Michal Uhr is the responsible product manager for the APOLLO , APOLLO MR3T and ASTOR room lasers from LAP .
Before switching to product management , Michael gained extensive experience @ @ @ @ @ @ @ customer sites worldwide .

Available to watch now, LAP GmbH Laser Applikationen explores how lasers make the difference in MRI in RT
Want to learn more on this subject? Watch now
There have been enormous improvements in MRI over the last 20 years. MR-only workflows and the invention of MR-guided linacs brought new perspectives into radiation therapy. Are lasers still important for the alignment of patients on MRI? What kind of different workflows are currently practised in RT?
(Courtesy: Royal Philips)
The webinar presented by Raphael Schmidt and Michael Uhr will help the audience to:
Learn more about workflows in MR
Get to know the relevance of lasers for patient alignment
Get an overview on different solutions for MRI and MR-linac
Want to learn more on this subject? Watch now
Raphael Schmidt is responsible for the product management of laser systems for CT and MRI from LAP. During his studies at the Karlsruhe Institute of Technology (KIT) he gained broad experience in different workflows in radiation therapy while analyzing them. The topic of his final thesis dealt with the improvement of workflows in RT trough new information and assistance systems. Schmidt holds a degree in industrial engineering and management.
Michal Uhr is the responsible product manager for the APOLLO, APOLLO MR3T and ASTOR room lasers from LAP. Before switching to product management, Michael gained extensive experience in LAP service over many years at customer sites worldwide.


physicsworld--2020-07-02--Four-charm tetraquark has been spotted at CERN - Physics World

The first tetraquark comprising all charm quarks and antiquarks may have been spotted by physicists working on the LHCb experiment on the Large Hadron Collider ( LHC ) at CERN .
The exotic hadron was discovered as it decayed into two J/ψ mesons , each of which is made from a charm quark and charm antiquark .
The particle appears to be the first known tetraquark to be made entirely of “ heavy quarks ” , which are the charm and beauty quarks ( but not the top quark , which is the heaviest quark but does not form hadrons @ @ @ @ @ @ @ four quarks are already exotic , and the one we have just discovered is the first to be made up of four heavy quarks of the same type , specifically two charm quarks and two charm antiquarks , ” explains Giovanni Passaleva , who is just stepping down as spokesperson for LHCb .
“ Up until now , the LHCb and other experiments had only observed tetraquarks with two heavy quarks at most and none with more than two quarks of the same type.
” The new tetraquark is dubbed X ( 6900 @ @ @ @ @ @ @ its mass of 6900 MeV/c2 ( 6.9 GeV/c2 ) .
The X denotes the fact that LHCb physicists are not yet certain about key properties of the particle including its spin , parity and quark content .
Hadrons are made of two or more bound quarks or antiquarks .
Mesons comprise a quark and antiquark , whereas baryons such as protons and neutrons comprise three quarks .
However , nature does not stop at three quarks and several tetraquarks ( two quarks and two antiquarks ) and pentaquarks ( four quarks and an @ @ @ @ @ @ @ for the X ( 6900 ) tetraquark comes as a bump in the mass distribution spectrum of pairs of J/ψ particles produced by proton-proton collisions at the LHC .
The bump has a statistical significance of more than 5σ , which is considered a discovery in particle physics .
The bump is centred at 6.9 GeV/c2 , which is well within the 5.8–7.4 GeV/c2 mass range predicted for a tetraquark comprising two charm quarks and two charm antiquarks .
An important question surrounding tetraquarks and pentaquarks is the nature of their internal structures @ @ @ @ @ @ @ between quarks , which are extremely difficult to calculate .
In a tetraquark , for example , the quarks and antiquarks could all be tightly bound together – or they could be arranged as two quark–antiquark pairs loosely bound in a molecule-like structure .
Or indeed , a tetraquark could have a configuration somewhere between these two extremes .
“ This new result provides further crucial evidence on the behaviour of quarks and how they interact through the strong force , ” says Tim Gershon of the University of Warwick and spokesperson for @ @ @ @ @ @ @ be of great interest to theorists working to better understand exotic hadrons.
” “ Data that we will collect with an upgraded [ LHCb ] detector in the coming years will allow us to widen the search for further such particles , and may resolve once and for all the debate over their substructure.
” X ( 6900 ) is described in a preprint on arXiv .

Charmed existence: conceptual illustration of a tetraquark. (Courtesy: CERN)
The first tetraquark comprising all charm quarks and antiquarks may have been spotted by physicists working on the LHCb experiment on the Large Hadron Collider (LHC) at CERN. The exotic hadron was discovered as it decayed into two J/ψ mesons, each of which is made from a charm quark and charm antiquark. The particle appears to be the first known tetraquark to be made entirely of “heavy quarks”, which are the charm and beauty quarks (but not the top quark, which is the heaviest quark but does not form hadrons).
“Particles made up of four quarks are already exotic, and the one we have just discovered is the first to be made up of four heavy quarks of the same type, specifically two charm quarks and two charm antiquarks,” explains Giovanni Passaleva, who is just stepping down as spokesperson for LHCb. “Up until now, the LHCb and other experiments had only observed tetraquarks with two heavy quarks at most and none with more than two quarks of the same type.”
The new tetraquark is dubbed X(6900), with the number referring to its mass of 6900 MeV/c2 (6.9 GeV/c2). The X denotes the fact that LHCb physicists are not yet certain about key properties of the particle including its spin, parity and quark content.
Hadrons are made of two or more bound quarks or antiquarks. Mesons comprise a quark and antiquark, whereas baryons such as protons and neutrons comprise three quarks. However, nature does not stop at three quarks and several tetraquarks (two quarks and two antiquarks) and pentaquarks (four quarks and an antiquark) have been discovered.
Predicted mass
Evidence for the X(6900) tetraquark comes as a bump in the mass distribution spectrum of pairs of J/ψ particles produced by proton-proton collisions at the LHC. The bump has a statistical significance of more than 5σ, which is considered a discovery in particle physics. The bump is centred at 6.9 GeV/c2, which is well within the 5.8–7.4 GeV/c2 mass range predicted for a tetraquark comprising two charm quarks and two charm antiquarks.
An important question surrounding tetraquarks and pentaquarks is the nature of their internal structures. This is defined by strong-force interactions between quarks, which are extremely difficult to calculate. In a tetraquark, for example, the quarks and antiquarks could all be tightly bound together – or they could be arranged as two quark–antiquark pairs loosely bound in a molecule-like structure. Or indeed, a tetraquark could have a configuration somewhere between these two extremes.
“This new result provides further crucial evidence on the behaviour of quarks and how they interact through the strong force,” says Tim Gershon of the University of Warwick and spokesperson for LHCb-UK, adding “It will undoubtedly be of great interest to theorists working to better understand exotic hadrons.” “Data that we will collect with an upgraded [LHCb] detector in the coming years will allow us to widen the search for further such particles, and may resolve once and for all the debate over their substructure.”
X(6900) is described in a preprint on arXiv.