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Project acronym 2D-CHEM
Project Two-Dimensional Chemistry towards New Graphene Derivatives
Researcher (PI) Michal Otyepka
Host Institution (HI) UNIVERZITA PALACKEHO V OLOMOUCI
Summary The suite of graphene's unique properties and applications can be enormously enhanced by its functionalization. As non-covalently functionalized graphenes do not target all graphene's properties and may suffer from limited stability, covalent functionalization represents a promising way for controlling graphene's properties. To date, only a few well-defined graphene derivatives have been introduced. Among them, fluorographene (FG) stands out as a prominent member because of its easy synthesis and high stability. Being a perfluorinated hydrocarbon, FG was believed to be as unreactive as the two-dimensional counterpart perfluoropolyethylene (Teflon®). However, our recent experiments showed that FG is not chemically inert and can be used as a viable precursor for synthesizing graphene derivatives. This surprising behavior indicates that common textbook grade knowledge cannot blindly be applied to the chemistry of 2D materials. Further, there might be specific rules behind the chemistry of 2D materials, forming a new chemical discipline we tentatively call 2D chemistry. The main aim of the project is to explore, identify and apply the rules of 2D chemistry starting from FG. Using the knowledge gained of 2D chemistry, we will attempt to control the chemistry of various 2D materials aimed at preparing stable graphene derivatives with designed properties, e.g., 1-3 eV band gap, fluorescent properties, sustainable magnetic ordering and dispersability in polar media. The new graphene derivatives will be applied in sensing, imaging, magnetic delivery and catalysis and new emerging applications arising from the synergistic phenomena are expected. We envisage that new applications will be opened up that benefit from the 2D scaffold and tailored properties of the synthesized derivatives. The derivatives will be used for the synthesis of 3D hybrid materials by covalent linking of the 2D sheets joined with other organic and inorganic molecules, nanomaterials or biomacromolecules.
The suite of graphene's unique properties and applications can be enormously enhanced by its functionalization. As non-covalently functionalized graphenes do not target all graphene's properties and may suffer from limited stability, covalent functionalization represents a promising way for controlling graphene's properties. To date, only a few well-defined graphene derivatives have been introduced. Among them, fluorographene (FG) stands out as a prominent member because of its easy synthesis and high stability. Being a perfluorinated hydrocarbon, FG was believed to be as unreactive as the two-dimensional counterpart perfluoropolyethylene (Teflon®). However, our recent experiments showed that FG is not chemically inert and can be used as a viable precursor for synthesizing graphene derivatives. This surprising behavior indicates that common textbook grade knowledge cannot blindly be applied to the chemistry of 2D materials. Further, there might be specific rules behind the chemistry of 2D materials, forming a new chemical discipline we tentatively call 2D chemistry. The main aim of the project is to explore, identify and apply the rules of 2D chemistry starting from FG. Using the knowledge gained of 2D chemistry, we will attempt to control the chemistry of various 2D materials aimed at preparing stable graphene derivatives with designed properties, e.g., 1-3 eV band gap, fluorescent properties, sustainable magnetic ordering and dispersability in polar media. The new graphene derivatives will be applied in sensing, imaging, magnetic delivery and catalysis and new emerging applications arising from the synergistic phenomena are expected. We envisage that new applications will be opened up that benefit from the 2D scaffold and tailored properties of the synthesized derivatives. The derivatives will be used for the synthesis of 3D hybrid materials by covalent linking of the 2D sheets joined with other organic and inorganic molecules, nanomaterials or biomacromolecules.
Project Ab-initio adiabatic-connection curves for density-functional analysis and construction
Researcher (PI) Trygve Ulf Helgaker
Host Institution (HI) UNIVERSITETET I OSLO
Summary Quantum chemistry provides two approaches to molecular electronic-structure calculations: the systematically refinable but expensive many-body wave-function methods and the inexpensive but not systematically refinable Kohn Sham method of density-functional theory (DFT). The accuracy of Kohn Sham calculations is determined by the quality of the exchange correlation functional, from which the effects of exchange and correlation among the electrons are extracted using the density rather than the wave function. However, the exact exchange correlation functional is unknown—instead, many approximate forms have been developed, by fitting to experimental data or by satisfying exact relations. Here, a new approach to density-functional analysis and construction is proposed: the Lieb variation principle, usually regarded as conceptually important but impracticable. By invoking the Lieb principle, it becomes possible to approach the development of approximate functionals in a novel manner, being directly guided by the behaviour of exact functional, accurately calculated for a wide variety of chemical systems. In particular, this principle will be used to calculate ab-initio adiabatic connection curves, studying the exchange correlation functional for a fixed density as the electronic interactions are turned on from zero to one. Pilot calculations have indicated the feasibility of this approach in simple cases—here, a comprehensive set of adiabatic-connection curves will be generated and utilized for calibration, construction, and analysis of density functionals, the objective being to produce improved functionals for Kohn Sham calculations by modelling or fitting such curves. The ABACUS approach will be particularly important in cases where little experimental information is available—for example, for understanding and modelling the behaviour of the exchange correlation functional in electromagnetic fields.
Quantum chemistry provides two approaches to molecular electronic-structure calculations: the systematically refinable but expensive many-body wave-function methods and the inexpensive but not systematically refinable Kohn Sham method of density-functional theory (DFT). The accuracy of Kohn Sham calculations is determined by the quality of the exchange correlation functional, from which the effects of exchange and correlation among the electrons are extracted using the density rather than the wave function. However, the exact exchange correlation functional is unknown—instead, many approximate forms have been developed, by fitting to experimental data or by satisfying exact relations. Here, a new approach to density-functional analysis and construction is proposed: the Lieb variation principle, usually regarded as conceptually important but impracticable. By invoking the Lieb principle, it becomes possible to approach the development of approximate functionals in a novel manner, being directly guided by the behaviour of exact functional, accurately calculated for a wide variety of chemical systems. In particular, this principle will be used to calculate ab-initio adiabatic connection curves, studying the exchange correlation functional for a fixed density as the electronic interactions are turned on from zero to one. Pilot calculations have indicated the feasibility of this approach in simple cases—here, a comprehensive set of adiabatic-connection curves will be generated and utilized for calibration, construction, and analysis of density functionals, the objective being to produce improved functionals for Kohn Sham calculations by modelling or fitting such curves. The ABACUS approach will be particularly important in cases where little experimental information is available—for example, for understanding and modelling the behaviour of the exchange correlation functional in electromagnetic fields.
Project acronym APARTHEID-STOPS
Project Apartheid -- The Global Itinerary: South African Cultural Formations in Transnational Circulation, 1948-1990
Researcher (PI) Louise Bethlehem
Host Institution (HI) THE HEBREW UNIVERSITY OF JERUSALEM
Summary This proposal proceeds from an anomaly. Apartheid routinely breached the separation that it names. Whereas the South African regime was deeply isolationist in international terms, new research links it to the Cold War and decolonization. Yet this trend does not consider sufficiently that the global contest over the meaning of apartheid and resistance to it occurs on the terrain of culture. My project argues that studying the global circulation of South African cultural formations in the apartheid era provides novel historiographic leverage over Western liberalism during the Cold War. It recasts apartheid as an apparatus of transnational cultural production, turning existing historiography inside out. This study seeks: • To provide the first systematic account of the deterritorialization of "apartheid"—as political signifier and as apparatus generating circuits of transnational cultural production. • To analyze these itinerant cultural formations across media and national borders, articulating new intersections. • To map the itineraries of major South African exiles, where exile is taken to be a system of interlinked circuits of affiliation and cultural production. • To revise the historiography of states other than South Africa through the lens of deterritorialized apartheid-era formations at their respective destinations. • To show how apartheid reveals contradictions within Western liberalism during the Cold War, with special reference to racial inequality. Methodologically, I introduce the model of thick convergence to analyze three periods: 1. Kliptown & Bandung: Novel possibilities, 1948-1960. 2. Sharpeville & Memphis: Drumming up resistance, 1960-1976. 3. From Soweto to Berlin: Spectacle at the barricades, 1976-1990. Each explores a cultural dominant in the form of texts, soundscapes or photographs. My work stands at the frontier of transnational research, furnishing powerful new insights into why South Africa matters on the stage of global history.
This proposal proceeds from an anomaly. Apartheid routinely breached the separation that it names. Whereas the South African regime was deeply isolationist in international terms, new research links it to the Cold War and decolonization. Yet this trend does not consider sufficiently that the global contest over the meaning of apartheid and resistance to it occurs on the terrain of culture. My project argues that studying the global circulation of South African cultural formations in the apartheid era provides novel historiographic leverage over Western liberalism during the Cold War. It recasts apartheid as an apparatus of transnational cultural production, turning existing historiography inside out. This study seeks: • To provide the first systematic account of the deterritorialization of "apartheid"—as political signifier and as apparatus generating circuits of transnational cultural production. • To analyze these itinerant cultural formations across media and national borders, articulating new intersections. • To map the itineraries of major South African exiles, where exile is taken to be a system of interlinked circuits of affiliation and cultural production. • To revise the historiography of states other than South Africa through the lens of deterritorialized apartheid-era formations at their respective destinations. • To show how apartheid reveals contradictions within Western liberalism during the Cold War, with special reference to racial inequality. Methodologically, I introduce the model of thick convergence to analyze three periods: 1. Kliptown & Bandung: Novel possibilities, 1948-1960. 2. Sharpeville & Memphis: Drumming up resistance, 1960-1976. 3. From Soweto to Berlin: Spectacle at the barricades, 1976-1990. Each explores a cultural dominant in the form of texts, soundscapes or photographs. My work stands at the frontier of transnational research, furnishing powerful new insights into why South Africa matters on the stage of global history.
Project acronym BANDWIDTH
Project The cost of limited communication bandwidth in distributed computing
Researcher (PI) Keren CENSOR-HILLEL
Summary Distributed systems underlie many modern technologies, a prime example being the Internet. The ever-increasing abundance of distributed systems necessitates their design and usage to be backed by strong theoretical foundations. A major challenge that distributed systems face is the lack of a central authority, which brings many aspects of uncertainty into the environment, in the form of unknown network topology or unpredictable dynamic behavior. A practical restriction of distributed systems, which is at the heart of this proposal, is the limited bandwidth available for communication between the network components. A central family of distributed tasks is that of local tasks, which are informally described as tasks which are possible to solve by sending information through only a relatively small number of hops. A cornerstone example is the need to break symmetry and provide a better utilization of resources, which can be obtained by the task of producing a valid coloring of the nodes given some small number of colors. Amazingly, there are still huge gaps between the known upper and lower bounds for the complexity of many local tasks. This holds even if one allows powerful assumptions of unlimited bandwidth. While some known algorithms indeed use small messages, the complexity gaps are even larger compared to the unlimited bandwidth case. This is not a mere coincidence, and in fact the existing theoretical infrastructure is provably incapable of giving stronger lower bounds for many local tasks under limited bandwidth. This proposal zooms in on this crucial blind spot in the current literature on the theory of distributed computing, namely, the study of local tasks under limited bandwidth. The goal of this research is to produce fast algorithms for fundamental distributed local tasks under restricted bandwidth, as well as understand their limitations by providing lower bounds.
Distributed systems underlie many modern technologies, a prime example being the Internet. The ever-increasing abundance of distributed systems necessitates their design and usage to be backed by strong theoretical foundations. A major challenge that distributed systems face is the lack of a central authority, which brings many aspects of uncertainty into the environment, in the form of unknown network topology or unpredictable dynamic behavior. A practical restriction of distributed systems, which is at the heart of this proposal, is the limited bandwidth available for communication between the network components. A central family of distributed tasks is that of local tasks, which are informally described as tasks which are possible to solve by sending information through only a relatively small number of hops. A cornerstone example is the need to break symmetry and provide a better utilization of resources, which can be obtained by the task of producing a valid coloring of the nodes given some small number of colors. Amazingly, there are still huge gaps between the known upper and lower bounds for the complexity of many local tasks. This holds even if one allows powerful assumptions of unlimited bandwidth. While some known algorithms indeed use small messages, the complexity gaps are even larger compared to the unlimited bandwidth case. This is not a mere coincidence, and in fact the existing theoretical infrastructure is provably incapable of giving stronger lower bounds for many local tasks under limited bandwidth. This proposal zooms in on this crucial blind spot in the current literature on the theory of distributed computing, namely, the study of local tasks under limited bandwidth. The goal of this research is to produce fast algorithms for fundamental distributed local tasks under restricted bandwidth, as well as understand their limitations by providing lower bounds.
Project acronym BeadsOnString
Project Beads on String Genomics: Experimental Toolbox for Unmasking Genetic / Epigenetic Variation in Genomic DNA and Chromatin
Researcher (PI) Yuval Ebenstein
Summary Next generation sequencing (NGS) is revolutionizing all fields of biological research but it fails to extract the full range of information associated with genetic material and is lacking in its ability to resolve variations between genomes. The high degree of genome variation exhibited both on the population level as well as between genetically "identical" cells (even in the same organ) makes genetic and epigenetic analysis on the single cell and single genome level a necessity. Chromosomes may be conceptually represented as a linear one-dimensional barcode. However, in contrast to a traditional binary barcode approach that considers only two possible bits of information (1 & 0), I will use colour and molecular structure to expand the variety of information represented in the barcode. Like colourful beads threaded on a string, where each bead represents a distinct type of observable, I will label each type of genomic information with a different chemical moiety thus expanding the repertoire of information that can be simultaneously measured. A major effort in this proposal is invested in the development of unique chemistries to enable this labelling. I specifically address three types of genomic variation: Variations in genomic layout (including DNA repeats, structural and copy number variations), variations in the patterns of chemical DNA modifications (such as methylation of cytosine bases) and variations in the chromatin composition (including nucleosome and transcription factor distributions). I will use physical extension of long DNA molecules on surfaces and in nanofluidic channels to reveal this information visually in the form of a linear, fluorescent "barcode" that is read-out by advanced imaging techniques. Similarly, DNA molecules will be threaded through a nanopore where the sequential position of "bulky" molecular groups attached to the DNA may be inferred from temporal modulation of an ionic current measured across the pore.
Next generation sequencing (NGS) is revolutionizing all fields of biological research but it fails to extract the full range of information associated with genetic material and is lacking in its ability to resolve variations between genomes. The high degree of genome variation exhibited both on the population level as well as between genetically "identical" cells (even in the same organ) makes genetic and epigenetic analysis on the single cell and single genome level a necessity. Chromosomes may be conceptually represented as a linear one-dimensional barcode. However, in contrast to a traditional binary barcode approach that considers only two possible bits of information (1 & 0), I will use colour and molecular structure to expand the variety of information represented in the barcode. Like colourful beads threaded on a string, where each bead represents a distinct type of observable, I will label each type of genomic information with a different chemical moiety thus expanding the repertoire of information that can be simultaneously measured. A major effort in this proposal is invested in the development of unique chemistries to enable this labelling. I specifically address three types of genomic variation: Variations in genomic layout (including DNA repeats, structural and copy number variations), variations in the patterns of chemical DNA modifications (such as methylation of cytosine bases) and variations in the chromatin composition (including nucleosome and transcription factor distributions). I will use physical extension of long DNA molecules on surfaces and in nanofluidic channels to reveal this information visually in the form of a linear, fluorescent "barcode" that is read-out by advanced imaging techniques. Similarly, DNA molecules will be threaded through a nanopore where the sequential position of "bulky" molecular groups attached to the DNA may be inferred from temporal modulation of an ionic current measured across the pore.
Project acronym BEHAVFRICTIONS
Project Behavioral Implications of Information-Processing Frictions
Researcher (PI) Jakub STEINER
Host Institution (HI) NARODOHOSPODARSKY USTAV AKADEMIE VED CESKE REPUBLIKY VEREJNA VYZKUMNA INSTITUCE
Summary BEHAVFRICTIONS will use novel models focussing on information-processing frictions to explain choice patterns described in behavioral economics and psychology. The proposed research will provide microfoundations that are essential for (i) identification of stable preferences, (ii) counterfactual predictions, and (iii) normative conclusions. (i) Agents who face information-processing costs must trade the precision of choice against information costs. Their behavior thus reflects both their stable preferences and the context-dependent procedures that manage their errors stemming from imperfect information processing. In the absence of micro-founded models, the two drivers of the behavior are difficult to disentangle for outside observers. In some pillars of the proposal, the agents follow choice rules that closely resemble logit rules used in structural estimation. This will allow me to reinterpret the structural estimation fits to choice data and to make a distinction between the stable preferences and frictions. (ii) Such a distinction is important in counterfactual policy analysis because the second-best decision procedures that manage the errors in choice are affected by the analysed policy. Incorporation of the information-processing frictions into existing empirical methods will improve our ability to predict effects of the policies. (iii) My preliminary results suggest that when an agent is prone to committing errors, biases--such as overconfidence, confirmatory bias, or perception biases known from prospect theory--arise under second-best strategies. By providing the link between the agent's environment and the second-best distribution of the perception errors, my models will delineate environments in which these biases shield the agents from the most costly mistakes from environments in which the biases turn into maladaptations. The distinction will inform the normative debate on debiasing.
BEHAVFRICTIONS will use novel models focussing on information-processing frictions to explain choice patterns described in behavioral economics and psychology. The proposed research will provide microfoundations that are essential for (i) identification of stable preferences, (ii) counterfactual predictions, and (iii) normative conclusions. (i) Agents who face information-processing costs must trade the precision of choice against information costs. Their behavior thus reflects both their stable preferences and the context-dependent procedures that manage their errors stemming from imperfect information processing. In the absence of micro-founded models, the two drivers of the behavior are difficult to disentangle for outside observers. In some pillars of the proposal, the agents follow choice rules that closely resemble logit rules used in structural estimation. This will allow me to reinterpret the structural estimation fits to choice data and to make a distinction between the stable preferences and frictions. (ii) Such a distinction is important in counterfactual policy analysis because the second-best decision procedures that manage the errors in choice are affected by the analysed policy. Incorporation of the information-processing frictions into existing empirical methods will improve our ability to predict effects of the policies. (iii) My preliminary results suggest that when an agent is prone to committing errors, biases--such as overconfidence, confirmatory bias, or perception biases known from prospect theory--arise under second-best strategies. By providing the link between the agent's environment and the second-best distribution of the perception errors, my models will delineate environments in which these biases shield the agents from the most costly mistakes from environments in which the biases turn into maladaptations. The distinction will inform the normative debate on debiasing.
Project acronym BIONICS
Project Bio-Inspired Routes for Controlling the Structure and Properties of Materials: Reusing proven tricks on new materials
Researcher (PI) Boaz Pokroy
Summary "In the course of biomineralization, organisms produce a large variety of functional biogenic crystals that exhibit fascinating mechanical, optical, magnetic and other characteristics. More specifically, when living organisms grow crystals they can effectively control polymorph selection as well as the crystal morphology, shape, and even atomic structure. Materials existing in nature have extraordinary and specific functions, yet the materials employed in nature are quite different from those engineers would select. I propose to emulate specific strategies used by organisms in forming structural biogenic crystals, and to apply these strategies biomimetically so as to form new structural materials with new properties and characteristics. This bio-inspired approach will involve the adoption of three specific biological strategies. We believe that this procedure will open up new ways to control the structure and properties of smart materials. The three bio-inspired strategies that we will utilize are: (i) to control the short-range order of amorphous materials, making it possible to predetermine the polymorph obtained when they transform from the amorphous to the succeeding crystalline phase; (ii) to control the morphology of single crystals of various functional materials so that they can have intricate and curved surfaces and yet maintain their single-crystal nature; (iii) to entrap organic molecules into single crystals of functional materials so as to tailor and manipulate their electronic structure. The proposed research has significant potential for opening up new routes for the formation of novel functional materials. Specifically, it will make it possible for us (1) to produce single, intricately shaped crystals without the need to etch, drill or polish; (2) to control the short-range order of amorphous materials and hence the polymorph of the successive crystalline phase; (3) to tune the band gap of semiconductors via incorporation of tailored bio-molecules."
"In the course of biomineralization, organisms produce a large variety of functional biogenic crystals that exhibit fascinating mechanical, optical, magnetic and other characteristics. More specifically, when living organisms grow crystals they can effectively control polymorph selection as well as the crystal morphology, shape, and even atomic structure. Materials existing in nature have extraordinary and specific functions, yet the materials employed in nature are quite different from those engineers would select. I propose to emulate specific strategies used by organisms in forming structural biogenic crystals, and to apply these strategies biomimetically so as to form new structural materials with new properties and characteristics. This bio-inspired approach will involve the adoption of three specific biological strategies. We believe that this procedure will open up new ways to control the structure and properties of smart materials. The three bio-inspired strategies that we will utilize are: (i) to control the short-range order of amorphous materials, making it possible to predetermine the polymorph obtained when they transform from the amorphous to the succeeding crystalline phase; (ii) to control the morphology of single crystals of various functional materials so that they can have intricate and curved surfaces and yet maintain their single-crystal nature; (iii) to entrap organic molecules into single crystals of functional materials so as to tailor and manipulate their electronic structure. The proposed research has significant potential for opening up new routes for the formation of novel functional materials. Specifically, it will make it possible for us (1) to produce single, intricately shaped crystals without the need to etch, drill or polish; (2) to control the short-range order of amorphous materials and hence the polymorph of the successive crystalline phase; (3) to tune the band gap of semiconductors via incorporation of tailored bio-molecules."
Project acronym Bits2Cosmology
Project Time-domain Gibbs sampling: From bits to inflationary gravitational waves
Researcher (PI) Hans Kristian ERIKSEN
Summary The detection of primordial gravity waves created during the Big Bang ranks among the greatest potential intellectual achievements in modern science. During the last few decades, the instrumental progress necessary to achieve this has been nothing short of breathtaking, and we today are able to measure the microwave sky with better than one-in-a-million precision. However, from the latest ultra-sensitive experiments such as BICEP2 and Planck, it is clear that instrumental sensitivity alone will not be sufficient to make a robust detection of gravitational waves. Contamination in the form of astrophysical radiation from the Milky Way, for instance thermal dust and synchrotron radiation, obscures the cosmological signal by orders of magnitude. Even more critically, though, are second-order interactions between this radiation and the instrument characterization itself that lead to a highly non-linear and complicated problem. I propose a ground-breaking solution to this problem that allows for joint estimation of cosmological parameters, astrophysical components, and instrument specifications. The engine of this method is called Gibbs sampling, which I have already applied extremely successfully to basic CMB component separation. The new and ciritical step is to apply this method to raw time-ordered observations observed directly by the instrument, as opposed to pre-processed frequency maps. While representing a ~100-fold increase in input data volume, this step is unavoidable in order to break through the current foreground-induced systematics floor. I will apply this method to the best currently available and future data sets (WMAP, Planck, SPIDER and LiteBIRD), and thereby derive the world's tightest constraint on the amplitude of inflationary gravitational waves. Additionally, the resulting ancillary science in the form of robust cosmological parameters and astrophysical component maps will represent the state-of-the-art in observational cosmology in years to come.
The detection of primordial gravity waves created during the Big Bang ranks among the greatest potential intellectual achievements in modern science. During the last few decades, the instrumental progress necessary to achieve this has been nothing short of breathtaking, and we today are able to measure the microwave sky with better than one-in-a-million precision. However, from the latest ultra-sensitive experiments such as BICEP2 and Planck, it is clear that instrumental sensitivity alone will not be sufficient to make a robust detection of gravitational waves. Contamination in the form of astrophysical radiation from the Milky Way, for instance thermal dust and synchrotron radiation, obscures the cosmological signal by orders of magnitude. Even more critically, though, are second-order interactions between this radiation and the instrument characterization itself that lead to a highly non-linear and complicated problem. I propose a ground-breaking solution to this problem that allows for joint estimation of cosmological parameters, astrophysical components, and instrument specifications. The engine of this method is called Gibbs sampling, which I have already applied extremely successfully to basic CMB component separation. The new and ciritical step is to apply this method to raw time-ordered observations observed directly by the instrument, as opposed to pre-processed frequency maps. While representing a ~100-fold increase in input data volume, this step is unavoidable in order to break through the current foreground-induced systematics floor. I will apply this method to the best currently available and future data sets (WMAP, Planck, SPIDER and LiteBIRD), and thereby derive the world's tightest constraint on the amplitude of inflationary gravitational waves. Additionally, the resulting ancillary science in the form of robust cosmological parameters and astrophysical component maps will represent the state-of-the-art in observational cosmology in years to come.