Weak aggregation: State of the art, expectations and open questions

2016 ◽  
Vol 22 ◽  
pp. 113-119 ◽  
Author(s):  
Thomas Zemb ◽  
Werner Kunz
Keyword(s):  
State Of The Art ◽  
Aggregation State ◽  
Open Questions

Revisiting the High-Pressure Properties of the Metal-Organic Frameworks ZIF-8 and ZIF-67

2020 ◽  
Author(s):  
Pia Vervoorts ◽  
Stefan Burger ◽  
Karina Hemmer ◽  
Gregor Kieslich
Keyword(s):  
High Pressure ◽  
State Of The Art ◽  
Energy Landscape ◽  
Structural Flexibility ◽  
Zeolitic Imidazolate Frameworks ◽  
Stimuli Responsive ◽  
X Ray Diffraction ◽  
X Ray ◽  
Open Questions ◽  
Metal Organic

The zeolitic imidazolate frameworks ZIF-8 and ZIF-67 harbour a series of fascinating stimuli responsive properties. Looking at their responsitivity to hydrostatic pressure as stimulus, open questions exist regarding the isotropic compression with non-penetrating pressure transmitting media. By applying a state-of-the-art high-pressure powder X-ray diffraction setup, we revisit the high-pressure behaviour of ZIF-8 and ZIF-67 up to <i>p</i> = 0.4 GPa in small pressure increments. We observe a drastic, reversible change of high-pressure powder X-ray diffraction data at <i>p</i> = 0.3 GPa, discovering large volume structural flexibility in ZIF-8 and ZIF-67. Our results imply a shallow underlying energy landscape in ZIF-8 and ZIF-67, an observation that might point at rich polymorphism of ZIF-8 and ZIF-67, similar to ZIF-4(Zn).<br>

Revisiting the High-Pressure Properties of the Metal-Organic Frameworks ZIF-8 and ZIF-67

2020 ◽  
Author(s):  
Pia Vervoorts ◽  
Stefan Burger ◽  
Karina Hemmer ◽  
Gregor Kieslich
Keyword(s):  
High Pressure ◽  
State Of The Art ◽  
Energy Landscape ◽  
Structural Flexibility ◽  
Zeolitic Imidazolate Frameworks ◽  
Stimuli Responsive ◽  
X Ray Diffraction ◽  
X Ray ◽  
Open Questions ◽  
Metal Organic

The zeolitic imidazolate frameworks ZIF-8 and ZIF-67 harbour a series of fascinating stimuli responsive properties. Looking at their responsitivity to hydrostatic pressure as stimulus, open questions exist regarding the isotropic compression with non-penetrating pressure transmitting media. By applying a state-of-the-art high-pressure powder X-ray diffraction setup, we revisit the high-pressure behaviour of ZIF-8 and ZIF-67 up to <i>p</i> = 0.4 GPa in small pressure increments. We observe a drastic, reversible change of high-pressure powder X-ray diffraction data at <i>p</i> = 0.3 GPa, discovering large volume structural flexibility in ZIF-8 and ZIF-67. Our results imply a shallow underlying energy landscape in ZIF-8 and ZIF-67, an observation that might point at rich polymorphism of ZIF-8 and ZIF-67, similar to ZIF-4(Zn).<br>

scholarly journals Five-Card AND Computations in Committed Format Using Only Uniform Cyclic Shuffles

2021 ◽  
Author(s):  
Yuta Abe ◽  
Yu-ichi Hayashi ◽  
Takaaki Mizuki ◽  
Hideaki Sone
Keyword(s):  
State Of The Art ◽  
Research Topic ◽  
The State ◽  
Major Research ◽  
Open Questions

AbstractIn card-based cryptography, designing AND protocols in committed format is a major research topic. The state-of-the-art AND protocol proposed by Koch, Walzer, and Härtel in ASIACRYPT 2015 uses only four cards, which is the minimum permissible number. The minimality of their protocol relies on somewhat complicated shuffles having non-uniform probabilities of possible outcomes. Restricting the allowed shuffles to uniform closed ones entails that, to the best of our knowledge, six cards are sufficient: the six-card AND protocol proposed by Mizuki and Sone in 2009 utilizes the random bisection cut, which is a uniform and cyclic (and hence, closed) shuffle. Thus, a question has arisen: “Can we improve upon this six-card protocol using only uniform closed shuffles?” In other words, the existence or otherwise of a five-card AND protocol in committed format using only uniform closed shuffles has been one of the most important open questions in this field. In this paper, we answer the question affirmatively by designing five-card committed-format AND protocols using only uniform cyclic shuffles. The shuffles that our protocols use are the random cut and random bisection cut, both of which are uniform cyclic shuffles and can be easily implemented by humans.

Radiocarbon Dating and Egyptian Chronology—From the “Curve of Knowns” to Bayesian Modeling

2016 ◽  
Author(s):  
Felix Höflmayer
Keyword(s):  
Bayesian Modeling ◽  
Radiocarbon Dating ◽  
State Of The Art ◽  
Near Eastern ◽  
Open Questions ◽  
The World ◽  
Dating Method ◽  
To Come ◽  
Almost All ◽  
Egyptian Archaeology

Radiocarbon dating has become a standard dating method in archaeology almost all over the world. However, in the field of Egyptology and Near Eastern archaeology, the method is still not fully appreciated. Recent years have seen several major radiocarbon projects addressing Egyptian archaeology and chronology that have led to an intensified discussion regarding the application of radiocarbon dating within the field of Egyptology. This chapter reviews the contribution of radiocarbon dating to the discipline of Egyptology, discusses state-of-the-art applications and their impact on archaeological as well as chronological questions, and presents open questions that will be addressed in the years to come.

scholarly journals Electrophysiological signatures of memory reactivation in humans

2020 ◽  
Vol 375 (1799) ◽  
pp. 20190293 ◽  
Author(s):  
Thomas Schreiner ◽  
Tobias Staudigl
Keyword(s):  
Episodic Memory ◽  
Neural Activity ◽  
Crucial Role ◽  
Memory Retrieval ◽  
Functional Significance ◽  
State Of The Art ◽  
Memory Reactivation ◽  
Open Questions ◽  
Neural Processes

The reactivation of neural activity that was present during the encoding of an event is assumed to be essential for human episodic memory retrieval and the consolidation of memories during sleep. Pioneering animal work has already established a crucial role of memory reactivation to prepare and guide behaviour. Research in humans is now delineating the neural processes involved in memory reactivation during both wakefulness and sleep as well as their functional significance. Focusing on the electrophysiological signatures of memory reactivation in humans during both memory retrieval and sleep-related consolidation, this review provides an overview of the state of the art in the field. We outline recent advances, methodological developments and open questions and specifically highlight commonalities and differences in the neuronal signatures of memory reactivation during the states of wakefulness and sleep. This article is part of the Theo Murphy meeting issue ‘Memory reactivation: replaying events past, present and future’.

scholarly journals NONLINEAR WAVE PROPAGATION IN DISORDERED MEDIA

1991 ◽  
Vol 05 (18) ◽  
pp. 2825-2882 ◽  
Author(s):  
ANGEL SÁNCHEZ ◽  
LUIS VÁZQUEZ
Keyword(s):  
Wave Propagation ◽  
Nonlinear Wave ◽  
State Of The Art ◽  
Disordered Media ◽  
Nonlinear Wave Propagation ◽  
General Introduction ◽  
Current Trends ◽  
Open Questions ◽  
Klein Gordon ◽  
The Subject

We briefly review the state-of-the-art of research on nonlinear wave propagation in disordered media. The paper is intended to provide the non-specialist reader with a flavor of this active field of physics. Firstly, a general introduction to the subject is made. We describe the basic models and the ways to study disorder in connection with them. Secondly, analytical and numerical techniques suitable for this purpose are outlined. We summarize their features and comment on their respective advantages, drawbacks and applicability conditions. Thirdly, the Nonlinear Klein-Gordon and Schrödinger equations are chosen as specific examples. We collect a number of results that are representative of the phenomena arising from the competition between nonlinearity and disorder. The review is concluded with some remarks on open questions, main current trends and possible further developments.

scholarly journals Resilient gossip-inspired all-reduce algorithms for high-performance computing: Potential, limitations, and open questions

2018 ◽  
Vol 33 (2) ◽  
pp. 366-383
Author(s):  
Marc Casas ◽  
Wilfried N Gansterer ◽  
Elias Wimmer
Keyword(s):  
Fault Tolerance ◽  
High Performance Computing ◽  
High Performance ◽  
State Of The Art ◽  
The State ◽  
Reduction Algorithm ◽  
Data Corruption ◽  
Parallel Reduction ◽  
Open Questions ◽  
Performance Computing

We investigate the usefulness of gossip-based reduction algorithms in a high-performance computing (HPC) context. We compare them to state-of-the-art deterministic parallel reduction algorithms in terms of fault tolerance and resilience against silent data corruption (SDC) as well as in terms of performance and scalability. New gossip-based reduction algorithms are proposed, which significantly improve the state-of-the-art in terms of resilience against SDC. Moreover, a new gossip-inspired reduction algorithm is proposed, which promises a much more competitive runtime performance in an HPC context than classical gossip-based algorithms, in particular for low accuracy requirements.

scholarly journals QUASI-PERIODIC PULSATIONS IN SOLAR AND STELLAR FLARES. REVIEW

2020 ◽  
Vol 6 (1) ◽  
pp. 3-29
Author(s):  
Elena Kupriyanova ◽  
Dmitrii Kolotkov ◽  
Valery Nakariakov ◽  
Anastasiia Kaufman
Keyword(s):  
State Of The Art ◽  
The Sun ◽  
Periodic Modulation ◽  
Stellar Flares ◽  
Open Questions ◽  
Magnetic Spectrum ◽  
Similarities And Differences ◽  
Electro Magnetic ◽  
Accelerated Particles ◽  
Oscillatory Processes

This paper provides an overview of the state-of-the-art studies of oscillatory processes in solar and stellar flares, based on modern observational data from ground-based and space-borne instruments with high temporal, spatial, and spectral resolution in different electro-magnetic spectrum ranges. We examine the mechanisms that generate flare emission and its quasi-periodic modulation. We discuss similarities and differences between solar and stellar flares, and address associated problems of superflares on the Sun and space weather problems. Quasi-periodic pulsations (QPPs) of flare radiation are shown to be an effective tool for diagnosing both the flare processes themselves and the parameters of flare plasma and accelerated particles. We consider types of QPPs, their statistical properties, and methods of analysis, taking into account the non-stationarity of the QPPs’ parameters. We review the proposed mechanisms of QPPs and address open questions.

scholarly journals Procedural Attack! Procedural Generation for Populated Virtual Cities: A Survey

2017 ◽  
Vol 4 (2) ◽  
Author(s):  
Werner Gaisbauer ◽  
Helmut Hlavacs
Keyword(s):  
Virtual Worlds ◽  
Virtual World ◽  
State Of The Art ◽  
Procedural Content Generation ◽  
Procedural Generation ◽  
Open Questions ◽  
Virtual City ◽  
The One ◽  
In The Beginning ◽  
The City

On the one hand, creating rich virtual worlds "by hand" like in the game Grand Theft Auto V is hugely expensive and limited to large studios. On the other hand, procedural content generation (PCG) allows tiny teams to create huge worlds like Hello Games did with only four people (in the beginning) for the recently released game No Man's Sky. Following in the footsteps of Hello Games, this paper tries to equip the reader with an overview about the state-of-the-art of how to build such a virtual world, i.e., a populated virtual city with buildings, streets, parks, vegetation, humans, and vehicles, using just PCG assets. Each PCG asset that is envisioned to bring the city to life is grouped and discussed in detail and the latest research trends in PCG are presented together with open questions. Using the above-mentioned PCG assets, instead of months, a city can be built in a mere couple of minutes by a user without much experience in designing 3D assets. The city can then be used for many applications like games, virtual reality (VR), or film.

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