Article
Chemistry, Multidisciplinary
Mehran Amiri, Nicolas P. Martin, Ching-Lei Feng, Jacob Kreager Lovio, May Nyman
Summary: Polyoxometalates are molecular metal oxides that can be isolated without capping ligands, showing high negative charge. Carbonate can reassemble with highly reactive decaniobate to form new structures with strong interactions.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Physical
Vikram Singh Raghuwanshi, Christine Browne, Warren Batchelor, Gil Garnier
Summary: The self-assembly (SA) of cellulose nanocrystals (CNC) in suspensions is investigated, and it is found that CNC rods of different lengths exhibit different self-assembly behavior. Short rods form an isotropic phase at lower concentrations and become aligned in a nematic phase as the concentration increases. The interrod distance follows different power law slopes at different concentrations. In contrast, long rods remain in the isotropic phase throughout the concentration range. The SA and ordering of rods are influenced by the balance between attractive and repulsive forces. This understanding enables the engineering of CNC composites with unique optical properties for applications in sensors and bio-diagnostics.
JOURNAL OF COLLOID AND INTERFACE SCIENCE
(2023)
Article
Chemistry, Physical
Helena Mateos, Luigi Gentile, Sergio Murgia, Giuseppe Colafemmina, Mattia Collu, Johan Smets, Gerardo Palazzo
Summary: This study investigates the microstructure and micellization process of Soluplus at different concentrations. The results show the presence of two forms of micelles at all concentrations, and the micellization occurs at much higher concentrations than the critical micellar concentration. The micellization process is suggested to be thermally activated isodesmic self-assembly.
JOURNAL OF COLLOID AND INTERFACE SCIENCE
(2022)
Article
Chemistry, Physical
Christina Efthymiou, L. Magnus Bergstrom, Jannik Nedergaard Pedersen, Jan Skov Pedersen, Per Hansson
Summary: Through experiments, it was found that common amphiphilic drug molecules form small micelles during self-assembly, with micelle size reaching a maximum at a certain concentration and slightly decreasing at higher concentrations. An increase in drug concentration and decrease in pH lead to an increase in micelle charge, and the aggregation behavior of all studied drugs resembles that of conventional surfactants.
JOURNAL OF COLLOID AND INTERFACE SCIENCE
(2021)
Article
Polymer Science
Xiaohua Chang, Dengwen Hu, Liangren Chen, Yaping Wang, Yutian Zhu
Summary: Thermoresponsive block copolymer micelles have potential in biological applications, with studies showing that changes in hydrophobic/hydrophilic block ratio, micelle concentration and addition of salt can alter the cloud point. Increasing the amount of PLGA hydrophobic block significantly decreases the cloud point, while higher micelle concentration and salt addition also lower the cloud point.
Article
Mechanics
Malte Vassholz, Hannes P. Hoeppe, Johannes Hagemann, Juan M. Rossello, Markus Osterhoff, Robert Mettin, Johannes Moeller, Markus Scholz, Ulrike Boesenberg, Joerg Hallmann, Chan Kim, Alexey Zozulya, Wei Lu, Roman Shayduk, Anders Madsen, Tim Salditt
Summary: We investigate the evolution of pressure and structural dynamics in a microfluidic water jet after laser-induced dielectric breakdown using a combination of near-field holography with single femtosecond x-ray free-electron laser pulses and x-ray diffraction. During cavitation and jet breakup, shock waves are emitted along the jet, accompanied by pronounced changes in the structure factor of water. This indicates a transition to a high density liquid structure induced by the transient pressure increase.
Review
Chemistry, Physical
Kun Qian, Randall E. Winans, Tao Li
Summary: Understanding the nanostructures of liquid electrolytes is crucial for enhancing electrochemical energy storage capacities, but the solvation structures and molecular dynamics in electrolytes are difficult to probe. Small-angle X-ray scattering (SAXS) offers unique insights into molecular clusters and ion pairs in electrolytes, with excellent time-resolution for studying molecular dynamics. This review focuses on the microscopic understanding of liquid electrolytes by SAXS and highlights the unique capabilities of X-ray scattering for nanostructure characterization.
ADVANCED ENERGY MATERIALS
(2021)
Article
Biochemistry & Molecular Biology
Harald Rennhofer, Janea Kohnke, Jozef Keckes, Johannes Tintner, Christoph Unterweger, Thomas Zinn, Karl Deix, Helga Lichtenegger, Wolfgang Gindl-Altmutter
Summary: The utilization of low-cost carbon black from lignin relies heavily on the materials properties, such as pore structure and inner surfaces, which evolve with heat treatment temperature. The development of pore structure and graphitization increases with heat treatment temperature, leading to a shift in chemistry and bonding nature towards pure graphite. Heat treatment at 1600 degrees C may be sufficient for various applications, reducing production energy consumption while maintaining material properties.
Article
Materials Science, Multidisciplinary
Kakeru Obayashi, Kazutaka Kamitani, Chien-Wei Chu, Ryosuke Kawatoko, Chao-Hung Cheng, Atsushi Takahara, Ken Kojio
Summary: The internal structure of polyurethane adhesive undergoes changes during lap shear deformation, with an increase in the spacing of hard segment domains and the merging of tilt angle with the stretching direction. These findings are of great significance for the practical design of adhesives.
ACS APPLIED POLYMER MATERIALS
(2022)
Article
Chemistry, Multidisciplinary
Antara Pal, Carlo Andrea De Filippo, Thiago Ito, Md Arif Kamal, Andrei Petukhov, Cristiano De Michele, Peter Schurtenberger
Summary: Our study investigates the influence of an external magnetic field on the self-assembly of hematite-silica core-shell prolate colloids, revealing a counterintuitive phenomenon where prolate colloids self-assemble into oblate liquid crystalline phases. We found that the formation of this unusual sequence of field-induced structures is dictated not only by the aspect ratio, but also by subtle deviations from the ideal ellipsoidal shape. This study demonstrates the importance of particle shape in the field-directed self-assembly of colloidal structures.
Article
Chemistry, Physical
Ruoyu Xu, Liqun Kang, Konstantinos G. Papanikolaou, Bolun Wang, Sushila Marlow, Qian He, Peng Zhang, Jianfang Wang, Dan J. L. Brett, Michail Stamatakis, Feng Ryan Wang
Summary: This study investigates the degradation mechanism of PdPt alloys and finds that carefully designed Pt alloy structures can control surface oxygen behavior, thereby improving ORR catalytic performance and extending the lifespan of fuel cells.
JOURNAL OF CATALYSIS
(2022)
Article
Chemistry, Multidisciplinary
David Attia, Orit Mendelson, Yael Levi-Kalisman, Ronit Bitton, Rachel Yerushalmi-Rozen
Summary: The chiral environment of d-alanine solutions disrupts and modifies the assembly of cellulose nanocrystals into a chiral nematic mesophase, and this effect is specific to d-alanine and not caused by the adsorption of alanine molecules onto the CNC particles.
Article
Biochemistry & Molecular Biology
Alexander W. Mauney, Uma M. Muthurajan, Karolin Luger, Lois Pollack
Summary: Nucleosomes in eukaryotic cells are organized into higher order structures for genome compaction, and understanding their organization is crucial in studying DNA storage efficiency. Arrays of linked nucleosomes serve as models for understanding how DNA and protein properties affect their arrangement, while important questions remain regarding the effects of histone proteins and other chromatin-associated protein partners on nucleosome spacing.
NUCLEIC ACIDS RESEARCH
(2021)
Article
Biotechnology & Applied Microbiology
Theyencheri Narayanan, Axel Ruter, Ulf Olsson
Summary: This review explores the structural investigations of self-assembled peptide nanotubes using X-ray scattering techniques. Compared to electron microscopy, scattering methods allow for studies of nanotubes in solution under the right physicochemical conditions and probe their formation mechanisms. Additionally, a combination of X-ray scattering methods enables the elucidation of structural organization from the molecular scale to the nanotube dimension.
FRONTIERS IN BIOENGINEERING AND BIOTECHNOLOGY
(2021)
Article
Biotechnology & Applied Microbiology
Theyencheri Narayanan, Axel Ruter, Ulf Olsson
Summary: This brief report presents an X-ray scattering investigation of self-assembled nanotubes formed by a short peptide, demonstrating the quantitative determination of nanotube dimensions and crystalline organization within their walls, using amyloid-beta(16-22) peptide nanotubes as an illustrative example.
FRONTIERS IN BIOENGINEERING AND BIOTECHNOLOGY
(2021)
Article
Multidisciplinary Sciences
Peter Gronquist, Chengyuan Yao, Tal Ben-Nun, Nikoli Dryden, Peter Dueben, Shigang Li, Torsten Hoefler
Summary: The study introduces a mixed model that utilizes a subset of original weather trajectories combined with deep neural networks for post-processing to improve ensemble forecast skills. The model shows a relative improvement of over 14% in ensemble forecast skill (CRPS), with larger improvements seen for extreme weather events on select case studies. By using fewer trajectories, computational costs can be reduced while maintaining comparable results to the full ensemble.
PHILOSOPHICAL TRANSACTIONS OF THE ROYAL SOCIETY A-MATHEMATICAL PHYSICAL AND ENGINEERING SCIENCES
(2021)
Article
Geosciences, Multidisciplinary
Johann Dahm, Eddie Davis, Florian Deconinck, Oliver Elbert, Rhea George, Jeremy McGibbon, Tobias Wicky, Elynn Wu, Christopher Kung, Tal Ben-Nun, Lucas Harris, Linus Groner, Oliver Fuhrer
Summary: Through the Pace project, we have implemented the nonhydrostatic FV3 dynamical core and GFDL cloud microphysics scheme entirely in Python using the GT4Py domain-specific language. We demonstrate that Pace achieves high performance and portability, improves code readability and maintainability compared to the Fortran reference implementation, and can run at scale on supercomputers. Furthermore, we show how a Python-based simulation code enables new use cases and workflows.
GEOSCIENTIFIC MODEL DEVELOPMENT
(2023)
Proceedings Paper
Computer Science, Hardware & Architecture
Tal Ben-Nun, Berke Ates, Alexandru Calotoiu, Torsten Hoefler
Summary: This paper explores how control- and data-centric approaches can work together using the Multi-Level Intermediate Representation (MLIR) framework. By combining control-driven optimization with data movement minimization, the proposed pipeline outperforms MLIR and uncovers new optimization opportunities automatically.
PROCEEDINGS OF THE 21ST ACM/IEEE INTERNATIONAL SYMPOSIUM ON CODE GENERATION AND OPTIMIZATION, CGO 2023
(2023)
Proceedings Paper
Computer Science, Hardware & Architecture
Alexandru Calotoiu, Tal Ben-Nun, Grzegorz Kwasniewski, Johannes de Fine Licht, Timo Schneider, Philipp Schaad, Torsten Hoefler
Summary: The research proposes lifting C programs to a parametric dataflow representation for static data-centric analysis and automatic high-performance code generation. By separating writing code from optimizing for different hardware, efficient specialized versions can be generated from simple, portable C source code with the click of a button. This approach can identify parallelism and outperform existing compilers.
PROCEEDINGS OF THE 36TH ACM INTERNATIONAL CONFERENCE ON SUPERCOMPUTING, ICS 2022
(2022)
Proceedings Paper
Computer Science, Hardware & Architecture
Oliver Rausch, Tal Ben-Nun, Nikoli Dryden, Andrei Ivanov, Shigang Li, Torsten Hoefler
Summary: This article introduces a flexible and customizable deep learning model training optimization process based on data movement minimization, which helps researchers optimize training of arbitrary deep neural networks. By gradually transforming standard networks, it provides four levels of general-purpose transformations, from internal operator optimization to global data movement reduction.
PROCEEDINGS OF THE 36TH ACM INTERNATIONAL CONFERENCE ON SUPERCOMPUTING, ICS 2022
(2022)
Proceedings Paper
Computer Science, Hardware & Architecture
Tal Ben-Nun, Linus Groner, Florian Deconinck, Tobias Wicky, Eddie Davis, Johann Dahm, Oliver D. Elbert, Rhea George, Jeremy McGibbon, Lukas Trumper, Elynn Wu, Oliver Fuhrer, Thomas Schulthess, Torsten Hoefler
Summary: This study presents an optimization approach for weather and climate applications, achieving significant performance improvements by abstracting hardware details and utilizing optimization techniques.
SC22: INTERNATIONAL CONFERENCE FOR HIGH PERFORMANCE COMPUTING, NETWORKING, STORAGE AND ANALYSIS
(2022)
Article
Automation & Control Systems
Torsten Hoefler, Dan Alistarh, Tal Ben-Nun, Nikoli Dryden, Alexandra Peste
Summary: This paper surveys previous work on sparsity in deep learning and provides a comprehensive tutorial. Researchers describe the generalization ability of sparse networks, strategies for achieving model sparsity, and practical mechanisms for exploiting sparsity.
JOURNAL OF MACHINE LEARNING RESEARCH
(2021)
Proceedings Paper
Computer Science, Artificial Intelligence
Chris Cummins, Zacharias Fisches, Tal Ben-Nun, Torsten Hoefler, Michael O'Boyle, Hugh Leather
Summary: The paper discusses the application of machine learning in building compiler optimization heuristics, highlighting the challenges many machine learning methods face in program data flow analysis. By formulating data flow analysis as supervised learning tasks and introducing a dataset of programs and corresponding labels, the authors propose a language-independent representation of program semantics, PROGRAML, which overcomes limitations of prior works and improves performance on optimization tasks.
INTERNATIONAL CONFERENCE ON MACHINE LEARNING, VOL 139
(2021)
Proceedings Paper
Computer Science, Software Engineering
Johannes de Fine Licht, Andreas Kuster, Tiziano De Matteis, Tal Ben-Nun, Dominic Hofer, Torsten Hoefler
Summary: This study aims to map heterogeneous stencil computations to spatial computing systems to improve temporal locality and ensure deadlock freedom. The research achieved the highest performance record on FPGAs to date and successfully investigated a complex stencil program from a production application.
CGO '21: PROCEEDINGS OF THE 2021 IEEE/ACM INTERNATIONAL SYMPOSIUM ON CODE GENERATION AND OPTIMIZATION (CGO)
(2021)
Article
Computer Science, Theory & Methods
Shigang Li, Tal Ben-Nun, Giorgi Nadiradze, Salvatore Di Girolamo, Nikoli Dryden, Dan Alistarh, Torsten Hoefler
Summary: The study introduces a wait-avoiding stochastic optimizer, WAGMA-SGD, that reduces global communication through subgroup weight exchange while maintaining convergence rates similar to globally communicating SGD. Empirical results show significant advantages of the method across different tasks, particularly in training throughput and time-to-solution.
IEEE TRANSACTIONS ON PARALLEL AND DISTRIBUTED SYSTEMS
(2021)
Proceedings Paper
Computer Science, Hardware & Architecture
Tal Ben-Nun, Todd Gamblin, D. S. Hollman, Hari Krishnan, Chris J. Newburn
PROCEEDINGS OF 2020 IEEE/ACM INTERNATIONAL WORKSHOP ON PERFORMANCE, PORTABILITY AND PRODUCTIVITY IN HPC (P3HPC 2020)
(2020)
Proceedings Paper
Computer Science, Theory & Methods
Tal Ben-Nun, Johannes de Fine Licht, Alexandros N. Ziogas, Timo Schneider, Torsten Hoefler
PROCEEDINGS OF SC19: THE INTERNATIONAL CONFERENCE FOR HIGH PERFORMANCE COMPUTING, NETWORKING, STORAGE AND ANALYSIS
(2019)
Proceedings Paper
Computer Science, Theory & Methods
Alexandros Nikolaos Ziogas, Tal Ben-Nun, Guillermo Indalecio Fernandez, Timo Schneider, Mathieu Luisier, Torsten Hoefler
PROCEEDINGS OF SC19: THE INTERNATIONAL CONFERENCE FOR HIGH PERFORMANCE COMPUTING, NETWORKING, STORAGE AND ANALYSIS
(2019)
Proceedings Paper
Computer Science, Theory & Methods
Alexandros Nikolaos Ziogas, Tal Ben-Nun, Guillermo Indalecio Fernandez, Timo Schneider, Mathieu Luisier, Torsten Hoefler
PROCEEDINGS OF SC19: THE INTERNATIONAL CONFERENCE FOR HIGH PERFORMANCE COMPUTING, NETWORKING, STORAGE AND ANALYSIS
(2019)
Proceedings Paper
Computer Science, Hardware & Architecture
Tal Ben-Nun, Maciej Besta, Simon Huber, Alexandros Nikolaos Ziogas, Daniel Peter, Torsten Hoefler
2019 IEEE 33RD INTERNATIONAL PARALLEL AND DISTRIBUTED PROCESSING SYMPOSIUM (IPDPS 2019)
(2019)
