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Figure 1: Bimodal atomic force microscopy provides three-dimensional force vector maps with subatomic resolution. The cantilever is simultaneously oscillated laterally and vertically to determine the vector mapping over the buckled dimers on the Ge(001) surface. Credit: Osaka University Atomic force microscopy (AFM) is an extremely sensitive technique that allows us to image materials and/or characterize their physical properties on the atomic scale by sensing the force above material surfaces using a precisely controlled tip. However, conventional AFM only provides the surface normal component of the force (the Z direction) and ignores the components parallel to the surface (the X and Y directions). To fully characterize materials used in nanoscale devices, it is necessary to obtain information about parameters with directionality, such as electronic, magnetic, and elastic properties, in more than just the Z direction. That is, it is desirable to measure these parameters in the X and Y directions parallel to the surface of a material as well. Measuring the distribution of such material parameters on the atomic scale will increase our understanding of chemical composition and reactions, surface morphology, molecular manipulation, and nanomachine operation. A research group at Osaka University has recently developed an AFM-based approach called "bimodal AFM" to obtain information about material surfaces in the X, Y, and Z directions (that is, in three dimensions) on the subatomic scale. The researchers measured the total force between an AFM tip and material surface in the X, Y, and Z directions using a germanium (Ge) surface as a substrate. Their collaborative partner, the Institute of Physics of the Slovak Academy of Sciences, contributed computer simulations of the tip–surface interactions. The bimodal AFM approach was recently reported in Nature Physics. "A clean Ge(001) surface has alternately aligned anisotropic dimers, which are rotated by 90° across the step, meaning they show a two-domain structure," explains first author Yoshitaka Naitoh. "We probed the force fields from each domain in the vertical direction by oscillating the AFM tip at the flexural resonance frequency and in the parallel direction by oscillating it at the torsional one." The team first expressed the force components as vectors, providing the vector distribution above the surface at the subatomic scale. The computer simulation supported the experimental results and shed light on the nature of chemical tip termination and morphology and, in particular, helped to clarify the outstanding questions regarding the tip–surface distances in the experiment. "We measured the magnitude and direction of the force between the AFM tip and Ge surface on a subatomic scale in three dimensions," says Naitoh. "Such measurements will aid understanding of the structure and chemical reactions of functionalized surfaces." The developed bimodal AFM approach will allow researchers to investigate the physical properties of materials in greater detail on the nanoscale, which should facilitate development of devices, nanotechnology, and friction/lubrication systems. More information: Yoshitaka Naitoh et al. Subatomic-scale force vector mapping above a Ge(001) dimer using bimodal atomic force microscopy, Nature Physics (2017). DOI: 10.1038/nphys4083


Home > Press > Three-dimensional Direction-dependent Force Measurement at the Subatomic Scale: International researchers led by Osaka University develop a microscopy technique to probe materials at the subatomic scale in multiple directions simultaneously Abstract: Atomic force microscopy (AFM) is an extremely sensitive technique that allows us to image materials and/or characterize their physical properties on the atomic scale by sensing the force above material surfaces using a precisely controlled tip. However, conventional AFM only provides the surface normal component of the force (the Z direction) and ignores the components parallel to the surface (the X and Y directions). To fully characterize materials used in nanoscale devices, it is necessary to obtain information about parameters with directionality, such as electronic, magnetic, and elastic properties, in more than just the Z direction. That is, it is desirable to measure these parameters in the X and Y directions parallel to the surface of a material as well. Measuring the distribution of such material parameters on the atomic scale will increase our understanding of chemical composition and reactions, surface morphology, molecular manipulation, and nanomachine operation. A research group at Osaka University has recently developed an AFM-based approach called "bimodal AFM" to obtain information about material surfaces in the X, Y, and Z directions (that is, in three dimensions) on the subatomic scale. The researchers measured the total force between an AFM tip and material surface in the X, Y, and Z directions using a germanium (Ge) surface as a substrate. Their collaborative partner, the Institute of Physics of the Slovak Academy of Sciences, contributed computer simulations of the tip-surface interactions. The bimodal AFM approach was recently reported in Nature Physics. "A clean Ge(001) surface has alternately aligned anisotropic dimers, which are rotated by 90° across the step, meaning they show a two-domain structure," explains first author Yoshitaka Naitoh. "We probed the force fields from each domain in the vertical direction by oscillating the AFM tip at the flexural resonance frequency and in the parallel direction by oscillating it at the torsional one." The team first expressed the force components as vectors, providing the vector distribution above the surface at the subatomic scale. The computer simulation supported the experimental results and shed light on the nature of chemical tip termination and morphology and, in particular, helped to clarify the outstanding questions regarding the tip-surface distances in the experiment. "We measured the magnitude and direction of the force between the AFM tip and Ge surface on a subatomic scale in three dimensions," says Naitoh. "Such measurements will aid understanding of the structure and chemical reactions of functionalized surfaces." The developed bimodal AFM approach will allow researchers to investigate the physical properties of materials in greater detail on the nanoscale, which should facilitate development of devices, nanotechnology, and friction/lubrication systems. For more information, please click If you have a comment, please us. Issuers of news releases, not 7th Wave, Inc. or Nanotechnology Now, are solely responsible for the accuracy of the content.


News Article | May 10, 2017
Site: www.eurekalert.org

Osaka-- Atomic force microscopy (AFM) is an extremely sensitive technique that allows us to image materials and/or characterize their physical properties on the atomic scale by sensing the force above material surfaces using a precisely controlled tip. However, conventional AFM only provides the surface normal component of the force (the Z direction) and ignores the components parallel to the surface (the X and Y directions). To fully characterize materials used in nanoscale devices, it is necessary to obtain information about parameters with directionality, such as electronic, magnetic, and elastic properties, in more than just the Z direction. That is, it is desirable to measure these parameters in the X and Y directions parallel to the surface of a material as well. Measuring the distribution of such material parameters on the atomic scale will increase our understanding of chemical composition and reactions, surface morphology, molecular manipulation, and nanomachine operation. A research group at Osaka University has recently developed an AFM-based approach called "bimodal AFM" to obtain information about material surfaces in the X, Y, and Z directions (that is, in three dimensions) on the subatomic scale. The researchers measured the total force between an AFM tip and material surface in the X, Y, and Z directions using a germanium (Ge) surface as a substrate. Their collaborative partner, the Institute of Physics of the Slovak Academy of Sciences, contributed computer simulations of the tip-surface interactions. The bimodal AFM approach was recently reported in Nature Physics. "A clean Ge(001) surface has alternately aligned anisotropic dimers, which are rotated by 90° across the step, meaning they show a two-domain structure," explains first author Yoshitaka Naitoh. "We probed the force fields from each domain in the vertical direction by oscillating the AFM tip at the flexural resonance frequency and in the parallel direction by oscillating it at the torsional one." The team first expressed the force components as vectors, providing the vector distribution above the surface at the subatomic scale. The computer simulation supported the experimental results and shed light on the nature of chemical tip termination and morphology and, in particular, helped to clarify the outstanding questions regarding the tip-surface distances in the experiment. "We measured the magnitude and direction of the force between the AFM tip and Ge surface on a subatomic scale in three dimensions," says Naitoh. "Such measurements will aid understanding of the structure and chemical reactions of functionalized surfaces." The developed bimodal AFM approach will allow researchers to investigate the physical properties of materials in greater detail on the nanoscale, which should facilitate development of devices, nanotechnology, and friction/lubrication systems.


News Article | May 7, 2017
Site: motherboard.vice.com

This is a series around POWER, a Motherboard 360/VR documentary about nuclear energy. Follow along here. Comic book logic dictates that a high dose of radiation will turn you in the Hulk, Godzilla, Radioactive Man, or any number of other radiation-induced superbeings. In real life, it's more likely to be a cause of deleterious mutations than a shortcut to enhanced abilities, as shown by major ecological damage in nuclear meltdown fallout zones, like Chernobyl and Fukushima. These contaminated regions have become a popular destination for scientists interested in the immediate and long-term impact of radiation on wildlife, which has led to the formation of intriguing niche disciplines, like radioecology and radiobiology. Watch more on Motherboard in 360/VR: Nuclear From Above Understanding how living organisms adapt to radiation doses has a range of applications, from medicine to conservation, but one of the most overlooked is preparation for long-duration human space missions and interplanetary colonization, both of which involve sustained exposure to higher radiation doses than what we experience on Earth's surface. An experiment conducted on the International Space Station (ISS) last year examined this idea with the help of eight fungi species sourced from the Chernobyl exclusion zone. These strains sprung up in the wake of the 1986 meltdown, and two of them— Cladosporium moulds—seem to prefer radioactive surfaces. The fungal samples were curated by a team led by Kasthuri Venkateswaran, a senior research scientist at NASA's Jet Propulsion Laboratory, who goes by Venkat for short. Read More: Chernobyl Microbes Are Heading to the International Space Station "The radiation seen at Chernobyl is high, but this black fungi popped up first [after the meltdown] compared even to the bacteria," Venkat told me over the phone. "That is how we selected those fungi, from such a radiation-rich environment. These fungi persisted due to some sort of protein-coding and biomolecule information that protect against the radiation level." Would ingesting such a hardy mould give one radioactive superpowers? Not quite—or more accurately, not yet. The eventual goal of Venkat's research is to develop a fungi-based "sunblock" for outer space radiation that could be used to protect humans from the harmful effects of long-term exposure. The fungi was returned to Earth just a few months ago, so the results are preliminary, but Venkat and his colleagues are eager to pursue the research further. "We have to take all the precautions before building a human habitation on Mars and beyond," he told me. In addition to helping humans become more radiation-resistant, studying the wildlife in fallout regions can also yield insight into engineering crops that can survive the radiation environment beyond Earth—especially highly irradiated worlds like those in the Jupiter system. The Chernobyl exclusion zone is significantly more radioactive than the interior of proposed long-duration spacecraft, which makes it a bad direct analogy to outer space. But the ways in which crops develop tolerance to contaminated environments is rich with clues about surviving sustained doses of cosmic radiation. "Radiation-resistant genes can be incorporated into yeast cells that produce beer so that humans are willing to go to space—they will have a better beer to drink," Venkat said, as one example. Fallout zones are also useful testbeds for studying astrobiological questions about the search for aliens on other worlds, and the origins of life on our own planet. Flax crops grown at Chernobyl in the decades since the meltdown have demonstrated increasing resistance to contamination, for instance, leading some researchers to wonder if their genes are a kind of vestigial time capsule to the dawn of life on Earth. "My favorite speculation is that when life on Earth was evolving, radioactivity was much more present on Earth's surface than is today," Martin Hajduch, a senior scientist at the Slovak Academy of Sciences' Institute of Plant Genetics and Biotechnology, said of his research into Chernobyl flax. "And so the plants are somehow 'remembering' it, [which is] what helped them to adapt in Chernobyl's radioactive area." In this way, the world's worst nuclear disasters, which have threatened the health of our planet, may now help us understand our origins on Earth, and learn to survive the harsh conditions beyond it. Subscribe to Science Solved It, Motherboard's new show about the greatest mysteries that were solved by science.


Grant
Agency: European Commission | Branch: H2020 | Program: RIA | Phase: INFRAIA-1-2014-2015 | Award Amount: 5.00M | Year: 2015

A collective effort is needed to create the environmental research infrastructure for answering pressing questions in a world of rapid social, economic and environmental change. The overall aim of the eLTER project is to advance the European network of Long-Term Ecosystem Research sites and socio-ecological research platforms to provide highest quality services for multiple use of a distributed research infrastructure. eLTERs major objectives and methods are to: (1) identify user needs for the research infrastructure in relation to major societal challenges through consultations with scientific, policy and business stakeholders and horizon scanning; (2) streamline the design of a cost-efficient pan-European network, able to address multiple ecosystem research issues, in collaboration with related global and European research infrastructures, e.g. LifeWatch; (3) develop the organisational framework for data integration and enable virtual access to the LTER data by enabling data publishing through distributed Data Nodes and by providing access to data on key research challenges through a Data Integration Platform; (4) foster the societal relevance, usability and multiple use of information, data and services through new partnerships with the providers of remotely sensed data, analytical services and scenario testing models, and via the adoption of new measurement technologies. The LTER-Europe network and the European Critical Zone community will collaborate to achieve these goals. 162 sites in 22 countries will provide data on long-term trends in environmental change, some reaching back 100 years. Test cases using these data will address a range of environmental and social issues to push innovation in network level services and steer conceptual developments. The envisaged LTER Infrastructure will enable European-scale investigation of major ecosystems and socio-ecological systems, and support knowledge-based decision making at multiple levels.


Grant
Agency: European Commission | Branch: H2020 | Program: CSA | Phase: INFRADEV-02-2016 | Award Amount: 9.05M | Year: 2017

The European Solar Telescope (EST) will be a revolutionary Research Infrastructure that will play a major role in answering key questions in modern Solar Physics. This 4-meter class solar telescope, to be located in the Canary Islands, will provide solar physicists with the most advanced state-of-the-art observing tools to transform our understanding of the complex phenomena that drive the solar magnetic activity. The principal objective of the present Preparatory Phase is to provide both the EST international consortium and the funding agencies with a detailed plan regarding the implementation of EST. The specific objectives of the proposed preparatory phase are: (1) to explore possible legal frameworks and related governance schemes that can be used by agencies to jointly establish, construct and operate EST as a new research infrastructure, with the implementation of an intermediate temporary organisational structure, as a previous step for future phases of the project; (2) to explore funding schemes and funding sources for EST, including a proposal of financial models to make possible the combination of direct financial and in-kind contributions towards the construction and operation of EST; (3) to compare the two possible sites for EST in the Canary Islands Astronomical Observatories and prepare final site agreements; (4) to engage funding agencies and policy makers for a long-term commitment which guarantees the construction and operation phases of the Telescope; (5) to involve industry in the design of EST key elements to the required level of definition and validation for their final production; (6) to enhance and intensify outreach activities and strategic links with national agencies and the user communities of EST. To accomplish the aforementioned goals, this 4-year project, promoted by the European Association for Solar Telescopes (EAST) and the PRE-EST consortium, encompassing 23 research institutions from 16 countries, will set up the Project Office


Grant
Agency: European Commission | Branch: H2020 | Program: IA | Phase: NMBP-18-2016 | Award Amount: 9.03M | Year: 2017

Sustainability of energy systems goes through high penetration of renewable energy with huge volumes of electricity to transmit over long distances. The most advanced solution is the HVDC Supergrid. But fault currents remain an issue even if DC circuit breakers have emerged. These are not satisfying, whereas Superconducting Fault Current Limiters (SCFCLs) using REBCO tapes bring an attractive solution. SCFCLs have already proved their outstanding performances in MVAC systems, with a few commercial devices in service. However, present REBCO conductors cannot be readily used at very high voltages: the electrical field under current limitation is too low and leads to too long tapes and high cost. FASTGRID aims to improve and modify the REBCO conductor, in particular its shunt, in order to significantly enhance (2 to 3 times) the electric field and so the economical SCFCL attractiveness. A commercial tape will be upgraded to reach a higher critical current and enhanced homogeneity as compared to todays standards. For safer and better operation, the tapes normal zone propagation velocity will be increased by at least a factor of 10 using the patented current flow diverter concept. The shunt surface will also be functionalized to boost the thermal exchanges with coolant. This advanced conductor will be used in a smart DC SCFCL module (1 kA 50 kV). This one will include new functionalities and will be designed as sub-element of a real HVDC device. In parallel to this main line of work, developments will be carried out on a promising breakthrough path: ultra high electric field tapes based on sapphire substrates. FASTGRID will bring this to the next levels of technology readiness. In conclusion, FASTGRID project aims at improving significantly existing REBCO conductor architecture to make SCFCLs economically attractive for HVDC Supergrids. However, availability of such an advanced conductor will have an impact on virtually all other applications of HTS tapes.


Pocs J.,Slovak Academy of Sciences
Information Sciences | Year: 2012

The aim of this paper is to compare an approach of creating fuzzy concept lattices proposed by Popescu with several other approaches. Particularly, we show that this approach is in some way equivalent to the approach of Krajči called generalized concept lattices. We also give a straightforward generalization of Popescu's approach to non-homogeneous cases. © 2011 Elsevier Inc. All rights reserved.


Biely P.,Slovak Academy of Sciences
Biotechnology Advances | Year: 2012

Several plant polysaccharides are partially esterified with acetic acid. One of the roles of this modification is protection of plant cell walls against invading microorganisms. Acetylation of glycosyl residues of polysaccharides prevents hydrolysis of their glycosidic linkages by the corresponding glycoside hydrolases. In this way the acetylation also represents an obstacle of enzymatic saccharification of plant hemicelluloses to fermentable sugars which appears to be a hot topic of current research. We can eliminate this obstacle by alkaline extraction or pretreatment leading to saponification of ester linkages. However, this task has been accomplished in a different way in the nature. The acetyl groups became targets of microbial carbohydrate esterases that evolved to overcome the complexity of the plant cell walls and that cooperate with glycoside hydrolases in plant polysaccharide degradation. This article concentrates on enzymes deacetylating plant hemicelluloses excluding pectin. They are currently grouped in at least 8 families, specifically in CE families 1-7 and 16, originally assigned as acetylxylan esterases, the enzymes acting on hardwood acetyl glucuronoxylan and its fragments generated by endo-β-1, 4-xylanases. There are esterases deacetylating softwood galactoglucomannan, but they have not been classified yet. The enzymes present in CE families 1-7 differ in structure and substrate and positional specificity. There are families behaving as endo-type and exo-type deacetylates, i.e. esterases deacetylating internal sugar residues of partially acetylated polysaccharides and also esterases deacetylating non-reducing end sugar residues in oligosaccharides. With one exception, the enzymes of all mentioned CE families belong to serine type esterases. CE family 4 harbors enzymes that are metal-dependent aspartic esterases. Three-dimensional structures have been solved for members of the first seven CE families, however, there is still insufficient knowledge about their substrate specificity and real physiological role. Current knowledge on catalytic properties of the selected families of CEs is summarized in this review. Some of the families are emerging also as new biocatalysts for regioselective acylation and deacylation of carbohydrates. © 2012 Elsevier Inc.


Langer P.,Slovak Academy of Sciences
Frontiers in Neuroendocrinology | Year: 2010

High prevalence of thyroid and metabolic disorders has been repeatedly observed in the population living in the area of eastern Slovakia highly polluted by a mixture of PCBs, DDE and HCB since about 50 years ago. Among thyroid disorders, increase of thyroid volume as measured by ultrasound volumetry may be suggested as one of notable findings which appeared possibly related to increased OCs levels and to autoimmunity signs (e.g. positive thyroperoxidase antibodies in blood and/or hypoechogenicity image obtained by ultrasound), while some participation of individual susceptibility and also of immunogenic effect of OCs and iodine in this iodine replete country cannot be excluded. Another notable finding has been the increase of blood FT4 and TT3 positively related to high PCBs level. Such increased FT4 level has been found associated with TSH level in hyperthyroid range in about 2% of examined population from polluted area. High prevalence of thyroid autoimmune disorders strongly supported the assumption on impaired immune system and thus also on presumably increased prevalence of other autoimmune disorders in highly exposed population. In addition, markedly increased prevalence of prediabetes and diabetes significantly related to major OCs (PCBs, DDE and HCB) levels and accompanied by increasing level of cholesterol and triglycerides has been observed. The observations also suggested a role of prenatal exposure to OCs in the development of several adverse health signs (e.g. increased prevalence of thyroid antibodies, impaired fasting glucose level, increased thyroid volume, decreased thymus volume, decreased neurobehavioral performance, increased hearing and dental disorders) in young generation born to highly exposed mothers in polluted area. © 2010 Elsevier Inc.

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