Events | Seminar

  • seminar
    Date:
    23 December
    2024
    Monday
    Hours:
    11:00
    -
    12:00

    The Israel Rubinstein 4th Memorial Lecture -"The challenge of rechargeable batteries with very high energy density and prolonged cycle life: from basic science to practical devices"

    Location: Gerhard M.J. Schmidt Lecture Hall
    participants: Prof. Doron Aurbach
    Bar Ilan University, Department of Chemistry

    Abstract

    The development of high energy density, long running rechargeable batteries like Li ion batteries, that power so successfully all mobile electronic devices, can be considered as the greatest success of modern electrochemistry. However, the basis for this success was the capability of exploring most complex electrodes, electrolyte solutions and reactive interfaces by most sophisticated electroanalytical tools in conjunction with advanced spectroscopic and microscopic was a first-rate leader in electroanalytical ז"ל techniques. Professor Israel Rubinstein chemistry. I learned a lot from him. The main theme of this presentation is to examine what is the true horizons for advanced high energy density batteries that can promote the electro-mobility revolution. The limiting factor in Li-ion batteries in terms of energy density, cost, potential, durability and cycling efficiency are the cathode materials used. We will examine most energetic cathode materials and novel approaches we developed for their stabilization. We describe in this lecture which electrode materials can be relevant, methodologies of their stabilization by doping, coating, and affecting electrodes surface chemistry by the use of active additives. Most important cathode materials are comprising the 5 elements Li,Ni,Co,Mn,O at different stoichiometries that determine voltage and specific capacities. We will explain how the stoichiometry dictates basic cathodes properties.1,2 We will discuss the renaissance of Li metal-based rechargeable batteries.3 We have learned how the stabilize Li metal anodes in rechargeable batteries using reactive electrolyte solutions that induce excellent passivation through controlled surface reactions. The emphasis is on fluorinated co-solvents that open the door for a very rich surface chemistry that forms passivating surface films that behave as ideal solid electrolyte interphase on both anodes and cathodes in advanced secondary Li batteries. This field provides fascinating examples how systematic basic scientific work leads to development of most practical devices for energy storage & conversion.
  • seminar
    Date:
    18 December
    2024
    Wednesday
    Hours:
    11:00

    A Computational Perspective on Supercooled and Glassy Water

    Location: Gerhard M.J. Schmidt Lecture Hall
    participants: Prof. Pablo G. Debenedetti
  • seminar
    Date:
    3 December
    2024
    Tuesday
    Hours:
    14:00
    -
    15:00

    TBA

    Location: Gerhard M.J. Schmidt Lecture Hall
    participants: Prof. Natalie Elia
    Dept. of Life Sciences Ben-Gurion University
  • seminar
    Date:
    1 December
    2024
    Sunday
    Hours:
    11:00

    Fundamentals of Remote Sensing and Machine Learning for Earth Science

    Location: Sussman Family Building for Environmental Sciences
    participants: Anna Brook
    University of Haifa

    Abstract

    Our Laboratory focuses on research that drives technological, environmental and social change. It includes advanced technologies in the social aspect of environment management, embracing the complexity of the human-environment relationship, and physical model development for complex and non-trivial real-world problems in the era of climate change. Our ultimate goal is to bridge the gap between machine learning and geoscience for sustainability and environmental management at the national and international (mainly in the Mediterranean) scales. We understand that machine learning, in general, and deep learning, in particular, offer promising tools to build new data-driven models for Earth system components and thus build our understanding of ecosystems. Yet, accepting that data-driven machine learning approaches in geoscientific research cannot replace physical modelling but strongly complement and enrich it. Our primary scientific interests are developing hybrid approaches, coupling physical processes (physical laws and physics-domain-specific knowledge) with the versatility of data-driven machine learning, also known as physics-aware machine learning, to better understand the ecosystems, biodiversity, dynamic processes and environmental responses to stressors, and emphasizing sustainability and decision support system development aligned with the UN Sustainable Development Goals (SDGs).
  • seminar
    Date:
    10 November
    2024
    Sunday
    Hours:
    11:00

    Late Oxygenation of Marine Environments Revealed by Dolomite U-Pb Dating

    Location: Sussman Family Building for Environmental Sciences
    participants: Uri Ryb
    Hebrew University of Jerusalem

    Abstract

    causal relationships between evolution and oxygenation of the ocean are vigorously debated. At the heart of these uncertainties are inconsistencies among reconstructed timelines for the rise of O2 in marine habitats. Attempts to reconstruct the timing of marine oxygenation are often based on redox-sensitive geochemical proxies that are prone to post-depositional alteration. Thus, developing new proxies, more resistant to such alteration, is an important direction forward for constraining major changes in atmospheric and marine oxygen levels. Here, we utilize U–Pb dating in dolomite to reconstruct their (re)crystallization ages and initial 207Pb/206Pb ratios; we find that they are systematically younger and lower than expected, respectively. These observations are explained by the resetting of the U–Pb system long after deposition, followed by further evolution in a closed system. Initial 207Pb/206Pb ratios have decreased from expected terrestrial values in the interval between deposition and (re)crystallization, consistent with U decay, and can therefore be used to reconstruct the initial 238U/206Pb ratios during deposition. Within our dataset initial 238U/206Pb ratios remained low in Proterozoic to mid-Paleozoic samples and increased dramatically in samples from the late-Paleozoic–early- Mesozoic Eras. This rise is attributed to a higher ratio of U to Pb in seawater that in turn influenced the fluid composition of carbonate crystallization sites. Accordingly, we interpret the temporal shift in initial 238U/206Pb ratios to reflect a late-Paleozoic increase in oxygenation of marine environments, corroborating previously documented shifts in some redox-sensitive proxies. This timeline is consistent with evolution-driven mechanisms for the oxygenation of late Paleozoic marine environments and with suggestions that Neoproterozoic and early Paleozoic animals thrived in oceans that overall and on long time scales were oxygen-limited compared to the modern ocean.
  • seminar
    Date:
    3 November
    2024
    Sunday
    Hours:
    11:00

    Forensic seismic evidence for precursory mobilization in Gaza leading to the October 7 terrorist attack

    Location: Sussman Family Building for Environmental Sciences
    participants: Asaf Inbal
    Tel Aviv University

    Abstract

    Seismic waves excited by human activity frequently obscure signals due to tectonic processes and are discarded as a nuisance. Seismic noise-field analysis is, however, a powerful tool for characterizing anthropogenic activities. In this talk, I will briefly review the seismological fingerprints of anthropogenic noise sources and then present a scheme devised to identify precursory activity leading to the October 7 terrorist attack. The precursory activity in Gaza included massive mobilization, documented by multiple media outlets. Favorable conditions arose due to a temporary lack of anthropogenic activity in Israel, allowing remote seismic stations to record signals due to Gaza vehicle traffic in the early hours of Oct. 7. Seismogram analysis reveals a widespread signal that abruptly emerged above the nighttime noise levels about 20 minutes before the attack began. Statistical analysis suggests the signal is highly anomalous; tests for significance indicate that pre-attack inter-station correlations would emerge by chance only once every 18,000 years. Tripartite array analysis was used to detect surface waves, locate their sources, and demarcate the extent of preattack activity within the Gaza Strip. The signal’s amplitude, frequency, and spatiotemporal distribution appear to be aligned with vehicular traffic emanating from the south-central region of the Gaza Strip and extending towards its peripheries in the half-hour window preceding the invasion. This provides valuable tactical information and suggests embedding seismic noise-field analysis into decision-making protocols could enhance preparedness for terrorist attacks.
  • seminar
    Date:
    30 June
    2024
    Sunday
    Hours:
    11:00

    Data synthesis to assess the effects of climate change on agricultural production and food security

    Location: Sussman Family Building for Environmental Sciences
    participants: David Makowski
    INRAe & University Paris-Saclay

    Abstract

    Climate change is having an impact on agricultural production and food security. Rising temperatures, changes in rainfall patterns and extreme weather events can reduce crop yields, sometimes dramatically. However, climate change can also offer new opportunities, by generating more favorable climatic conditions for agricultural production in certain regions that were previously less productive. In order to assess the positive and negative impacts of climate change on agriculture and identify effective adaptation strategies, scientists have produced massive amounts of data during the last two decades, conducting local experiments in agricultural plots and using models to simulate the effect of climate on crop yields. In most cases, these data are not pooled together and are analyzed separately by different groups of scientists to assess the effects of climate change at a local level, without any attempt to upscale the results at a larger scale. Yet, if brought together, these data represent a rich source of information that are relevant to analyze the effect of climate across diverse environmental conditions. The wealth of data available has led to the emergence of a new type of scientific activity, involving the retrieval of all available data on a given subject and their synthesis into more robust and generic results. In this talk, I review the statistical methods available to synthesize data generated in studies quantifying the effect of climate change on agriculture. I discuss both the most classic methods - such as meta-analysis - and more recent methods based on machine learning. In particular, I show how this approach can be used to map the impact of climate change on a large scale (national, continental and global) from local data. I illustrate these methods in several case studies and present several research perspectives in this area.
  • seminar
    Date:
    25 June
    2024
    Tuesday
    Hours:
    11:00
    -
    12:00

    Molecular Manipulation of Heterogeneous Electrocatalysis Using Metal-Organic Frameworks

    Location: Gerhard M.J. Schmidt Lecture Hall
    participants: Prof. Idan Hod
    Department of Chemistry at Ben-Gurion University of the Negev, BGU

    Abstract

    Electrocatalytically driven reactions that produce alternative fuels and chemicals are considered as a useful means to store renewable energy in the form of chemical bonds. in recent years there has been a significant increase in research efforts aiming to develop highly efficient electrocatalysts that are able to drive those reactions. Yet, despite having made significant progress in this field, there is still a need for developing new materials that could function both as active and selective electrocatalysts. In that respect, Metal–Organic Frameworks (MOFs), are an emerging class of hybrid materials with immense potential in electrochemical catalysis. Yet, to reach a further leap in our understanding of electrocatalytic MOF-based systems, one also needs to consider the welldefined structure and chemical modularity of MOFs as another important virtue for efficient electrocatalysis, as it can be used to fine-tune the immediate chemical environment of the active site, and thus affect its overall catalytic performance. Our group utilizes Metal-Organic Frameworks (MOFs) based materials as a platform for imposing molecular approaches to control and manipulate heterogenous electrocatalytic systems. In this talk, I will present our recent study on electrocatalytic schemes involving MOFs, acting as: a) electroactive unit that incorporates molecular electrocatalysts, or b) non-electroactive MOF-based membranes coated on solid heterogenous catalysts.
  • seminar
    Date:
    16 June
    2024
    Sunday
    Hours:
    11:00

    On Microbes and Mountains: Unraveling the Links Between Microbial Weathering and Large-Scale Surface Processes

    Location: Sussman Family Building for Environmental Sciences
    participants: Michal Ben-Israel
    University of California

    Abstract

    Microorganisms play a crucial role in the weathering processes that transform rock into soil through chemical and physical mechanisms essential for nutrient cycling, nitrogen fixation, carbon storage, and organic matter decomposition. This intricate relationship between microbial life and landscapes forms the backbone of ecosystem dynamics and biogeochemical processes. Microbes influence rock weathering and soil production, adapting to their surroundings and creating distinct communities across various landscapes. These complex interactions and feedback mechanisms are pivotal to understanding the co-evolution of microbial communities and landscapes over time. However, existing research on microbial contributions to weathering and soil production has predominantly focused on relatively short timescales and small spatial scales. Understanding the interplay between the evolution of microbial communities and their role in weathering processes over geomorphic timescales within transient landscapes is important for a more complete understanding of how landscapes evolve as well as the impact of geomorphic changes on microbial community establishment and evolution. The main objective of this study is to elucidate the long-term dynamics of microbial communities and their role in weathering processes over millennial timescales. To achieve this, we focused on recently deglaciated basins in the Eastern Sierra Nevada, CA, examining bacterial community composition in three phases of the weathering process: exposed rock at the surface, saprolite—the weathered rock found beneath soil, and soil. Sampling along an elevational transect, we collected 25 samples of rock, soil, and saprolite, and evaluated their bacterial composition using 16S rRNA and metagenomic sequencing. Results show that both soil and saprolite samples exhibited diverse and similar microbial communities, indicating a developmental relationship between these habitats despite distinct geochemical compositions. In contrast, rock habitats are less diverse, and their composition resembles those of young deglaciated landscapes. Our findings point to a link between microbial community composition and rock-to-soil weathering processes, suggesting that the majority of weathering processes occur within the soil column (saprolite and soil), with exposed rock maintaining a steady state. The stability of these microbial communities over extended timescales suggests a potentially significant role for microbial weathering in landscape evolution. This finding underscores the importance of considering microbial contributions in future geomorphic studies, as they may play a key role in shaping the Earth's surface. Moving forward, we plan on coupling a long-term, landscape-scale geomorphic perspective with 'omics approaches from microbial ecology to comprehensively understand the complex relationships between microbial life and landscapes, ultimately advancing our knowledge of ecosystem dynamics and health.
  • seminar
    Date:
    5 June
    2024
    Wednesday
    Hours:
    10:00
    -
    11:00

    Memory consolidation and generalization during sleep

    Location: Nella and Leon Benoziyo Building for Brain Research
    participants: Ella Bar-Student Seminar-PhD Thesis Defense
    Prof. Rony Paz Lab & Prof. Yuval Nir, Tel Aviv University

    Abstract

    During sleep, our memories are reactivated and consolidated in an active process that significantly influences our memory and decision-making. In this talk, I will present two studies about sleep-memory consolidation. The first study investigated sleep memory consolidation's local versus global properties within the brain. By exploiting the unique functional neuroanatomy of olfactory system, we were able to manipulate sleep oscillations and enhance memories locally within a single hemisphere during sleep. These findings underscore the local nature of sleep memory consolidation, which can be selectively manipulated within the brain, thereby creating an important link between theories of local sleep and learning. The second research explored the relationship between generalization processes and sleep, acknowledging that overgeneralization of negative stimuli and disruptions in sleep quality contribute to anxiety and PTSD disorders. Specifically, we studied participants' responses to stimuli associated with positive, negative, or neutral outcomes. Our findings revealed significant correlations between brain activity, as detected by fMRI, during the association of a stimulus with an outcome and the perceptual generalization of these stimuli. While activity in limbic brain areas was correlated with immediate negative stimulus generalization, we observed that the activation in these areas predicted recovery and positively related generalization following sleep. Moreover, we identified specific sleep oscillations correlated with this recovery generalization using high-density EEG recordings. These results highlight the crucial role of sleep in both generalization processes and the restoration of balanced responses to stimuli. Understanding these mechanisms can offer valuable insights into developing therapeutic strategies for anxiety and PTSD.
  • seminar
    Date:
    4 June
    2024
    Tuesday
    Hours:
    14:00
    -
    15:00

    Synthetic Biology Platforms to Study Biological Systems and for Biomedical Applications

    Location: Gerhard M.J. Schmidt Lecture Hall
    participants: Dr. Lior Nissim
    The Faculty of Medicine Hebrew University
  • seminar
    Date:
    2 June
    2024
    Sunday
    Hours:
    11:00

    The Role of Cloud Morphology in Aerosol-Cloud Interactions 

    Location: Sussman Family Building for Environmental Sciences
    participants: Tom Goren
    Bar Ilan University

    Abstract

    Aerosol-cloud interactions are extensively studied to understand the climatic effect of anthropogenic aerosols, as the latter can change the radiative properties of clouds. Despite the clear presence of different cloud morphologies (i.e., the spatial variation of cloud thickness), the impact of aerosol-cloud interactions under different cloud morphologies is often overlooked. I will show that accounting for cloud morphology is essential for a better process understanding and for an accurate assessment of the radiative forcing due to aerosol-cloud interactions.
  • seminar
    Date:
    29 May
    2024
    Wednesday
    Hours:
    14:00
    -
    15:00

    Measuring conformational equilibria in allosteric proteins with time-resolved tmFRET

    Location: Gerhard M.J. Schmidt Lecture Hall
    participants: Prof. Sharona Gordon
    Professor of Physiology & Biophysics, University of Washington School of Medicine
  • seminar
    Date:
    28 May
    2024
    Tuesday
    Hours:
    14:00
    -
    15:00

    How to Enhance Sex Determination?

    Location: Gerhard M.J. Schmidt Lecture Hall
    participants: Dr. Nitzan Gonen
    The Mina and Everard Goodman Faculty of Life Sciences Institute of Nanotechnology and Advanced Materials, Bar-Ilan University
  • seminar
    Date:
    21 May
    2024
    Tuesday
    Hours:
    14:00
    -
    15:00

    Molecular-level insights into light-induced reactions in biological systems from multiscale simulations

    Location: Gerhard M.J. Schmidt Lecture Hall
    participants: Dr. Igor Shapiro
    Hebrew University
  • seminar
    Date:
    19 May
    2024
    Sunday
    Hours:
    11:00

    Floods in a warming climate: what are the missing puzzle pieces?

    Location: Sussman Family Building for Environmental Sciences
    participants: Efrat Morin
    The Hebrew University of Jerusalem

    Abstract

    Flood is the outcome of complex processes interacting at a range of scales. Flood generation and its magnitude depend on different precipitation and surface properties. As the climate becomes warmer globally, precipitation patterns are changing and, consequently, altering flood regimes. Resolving the expected changes in flood properties requires examining projections of precipitation features most correlated with floods. While the redistribution of mean annual precipitation amounts is generally known, the trends in many other essential factors controlling floods are yet to be resolved. For example, flash flood magnitude is sensitive to space-time rainstorm properties such as areal coverage or storm speed. Still, knowledge of how these properties are affected by global warming is lacking. Maximal rain rates for duration relevant to the watershed’s response time are also crucial parameters controlling the flood discharge. There is some understanding of how extreme rain rates change, but the magnitude and sign depend on the rain duration considered. Changes in frequency and the intra-seasonal distribution of precipitation events also affect flood regimes. Finally, watersheds of different properties are sensitive to different precipitation features, and thus, different watersheds may respond differently to global warming. In this talk, we will present the complexity of flood response under global warming and then focus on two questions: 1) how does global warming affect heavy precipitation events (HPEs) in the eastern Mediterranean, and 2) how these effects are imprinted in the resulting floods in small-medium Mediterranean watersheds. We simulated 41 eastern Mediterranean HPEs with the high-resolution weather research and forecasting (WRF) model. Each event was simulated twice: under historical conditions and at the end of the 21st-century conditions (RCP8.5 scenario) using the “pseudo global warming” approach. Comparison of precipitation patterns from the paired simulations revealed that heavy precipitation events in our region are expected to become drier and more spatiotemporally concentrated, i.e., we expect higher rain rates on smaller coverage areas and shorter storm durations that, in total, yield lower amounts of rainfall. These effects have some contradicting signs, and their full hydrological impact on streamflow peak discharge and volume was further explored. Ensembles of spatially-shifted rainfall data from the simulated HPEs were input to a high-resolution distributed hydrological model (GB-HYDRA) representing four small-medium-size watersheds (18–69 km2) in the eastern Mediterranean (Ramot Menashe). Flow volume is significantly reduced in future HPEs, while the change in flood peak is more complicated due to the combined effect of precipitation amount (decreasing) and precipitation rate (increasing). For the watersheds examined in this research, which are mostly agricultural, flood peaks at the watershed outlets are mostly reduced. The dynamics of flood generation at sub-watersheds of different sizes and properties are further examined in this research to understand scenarios for lowering or increasing flood peaks. This study emphasizes that detecting and quantifying global warming impact on space-time precipitation patterns is essential for flood regime projection.
  • seminar
    Date:
    12 May
    2024
    Sunday
    Hours:
    11:00

    Lake Kinneret in a Changing Environment

    Location: Sussman Family Building for Environmental Sciences
    participants: Yael Amitai
    Israel Oceanographic and Limnological Research, The Yigal Alon Kinneret Limnological Laboratory

    Abstract

    Located in a highly sensitive subtropical climate area and a densely populated area, Lake Kinneret is poised to undergo both natural and human-induced transformations in the coming decades. The lake is thermally stratified throughout most of the year and mixes thoroughly each winter when the epilimnion (upper layer) water temperature reaches equilibrium with the hypolimnion (bottom layer) water temperature by surface cooling and turbulence. Both the stratified and the fully mixed periods has a significant role in the Kinneret’s ecological system. Observation shows that air above the Lake is warming in a rate of 0.4oC/decade, while the epilimnion and hypolimnion are warming in a rate of 0.3oC/decade and 0.1oC/decade, respectively, for the last 50 years. Therefore, stratification strength and duration is anticipated to change and impact the lake’s ecosystem. Additionally, the sequence of drought periods and the expected future rise in water demands from Lake Kinneret formed the basis for the government's decision to channel desalinated water, via the natural course of the Tzalmon Stream, to the lake to ensure its operational functionality at high levels. Using a 3D hydrodynamic model forced by short and long-term forecasts the above scenarios are examined and analyzed. A simulation forced by regional atmospheric RCP4.5 climate change scenario spanning from 2010-2070 show continuous warming followed by abrupt cooling of the lake water around the year 2065. This result, presumably due to enhanced latent heat loss, suggest a restrain the dramatic anticipated change in the lake stratification.
  • seminar
    Date:
    7 May
    2024
    Tuesday
    Hours:
    14:00
    -
    15:00

    Chemical Probes Reveal Mechanisms of Action of Antifungal Drugs and Guide Modifications to Improve Performance

    Location: Gerhard M.J. Schmidt Lecture Hall
    participants: Prof. Micha Fridman
    School of Chemistry Tel-Aviv University
  • seminar
    Date:
    7 May
    2024
    Tuesday
    Hours:
    11:00

    Data Drought in the Humid Tropics: How to Overcome the Cloud Barrier in Greenhouse Gas Remote Sensing

    Location: Sussman Family Building for Environmental Sciences
    participants: Yinon Bar-On
    California Institute of Technology

    Abstract

    Quantifying land-atmosphere fluxes of carbon-dioxide (CO2) and methane (CH4) is essential for evaluating carbonclimate feedbacks. Greenhouse gas satellite missions aim to provide global observational coverage of greenhouse gas concentrations and thus improve inversions of landatmosphere exchange fluxes. However, in key regions such as the humid tropics current missions obtain very few valid measurements. Leveraging recent advances in the global analysis of high-resolution optical imagery on cloudcomputing platforms and deep learning algorithms for cloud segmentation, we quantitatively diagnose the sources for low data yields in the tropics. We find that the main cause for low data yields are frequent shallow cumulus clouds. We find that increasing the spatial resolution of observations to 200 m would increase yields by 2–3 orders of magnitude and allow regular measurements in the wet season. Thus, the key to effective tropical greenhouse gas observations likely lies in regularly acquiring high-spatial resolution data.
  • seminar
    Date:
    16 April
    2024
    Tuesday
    Hours:
    14:00
    -
    15:00

    High Throughput Approaches to Study the Roles of RNA Structures in Long RNAs

    Location: Gerhard M.J. Schmidt Lecture Hall
    participants: Prof. Igor Ulitsky,Prof. Igor Ulitsky,Prof. Igor Ulitsky
    Department of Immunology and Regenerative Biology, Faculty of Biology, WIS
  • seminar
    Date:
    9 April
    2024
    Tuesday
    Hours:
    14:00
    -
    15:00

    What Funga can teach us about DNA repair

    Location: Gerhard M.J. Schmidt Lecture Hall
    participants: Dr. Shay Covo
    Department of Plant Pathology and Microbiology Faculty of Agriculture, Food & Environment The Hebrew University of Jerusalem
  • seminar
    Date:
    7 April
    2024
    Sunday
    Hours:
    11:00

    Benthic side control on the chemical composition of the ocean

    Location: Sussman Family Building for Environmental Sciences
    participants: Zvi Steiner
    GEOMAR Helmholtz Centre

    Abstract

    The sediment – bottom-water interface is suggested as a key control on the chemical composition of the ocean by studies of trace elements in the ocean water-column, yet data regarding trace element fluxes and interactions taking place in the top ten cm of abyssal sediments are scarce. To bridge this gap, I analysed the trace and major element composition of porewater and sediment of red-clay sediment from the abyssal North Pacific, and hydrothermally influenced sediment from the Mid-Atlantic Ridge. The top sediment at both study regions is aerobic, nevertheless, there is large variability in the porewater concentrations of many elements at the top five cm. The North Pacific red-clay sediment is a source of cobalt, nickel, copper, arsenic, vanadium and barium to the deep-ocean, the magnitude of these fluxes is consistent with fluxes calculated based on the water-column distribution of most elements, and are equivalent to the global supply of these elements by rivers. The hydrothermally influenced sediment is a strong source of copper, zinc and cobalt up to three km from the vent due to oxidation of sulfide minerals. Close to the vents, the sediment is high in iron oxyhydroxides that adsorb the oxyanions vanadate, arsenate and phosphate, acting as a sink for these elements. The results of this study highlight the importance of red-clay sediment in shaping the chemical composition of the ocean, and suggest an important role for hydrothermally influenced sediment in modulating the contributions of hydrothermal vents to ocean biogeochemistry.
  • seminar
    Date:
    31 March
    2024
    Sunday
    Hours:
    11:00

    Large scale circulation adjustments to aerosol-cloud interactions and its radiative effect

    Location: Sussman Family Building for Environmental Sciences
    participants: Guy Dagan
    Hebrew University of Jerusalem

    Abstract

    The impact of anthropogenic aerosols on clouds is a leading source of uncertainty in estimating the effect of human activity on the climate system. The challenge lies in the scale difference between clouds (~1-10 km) and general circulation and climate (~1000 km). To address this, we utilize three different novel sets of simulations that allow to resolve convection while also including a epresentation of large-scale processes. Our findings demonstrate that aerosol-cloud interaction intensifies tropical overturning circulation. Employing a weak temperature gradient approximation, we attribute variations in circulation to clear-sky humidity changes driven by warm rain suppression by aerosols. In two sets of simulations accounting for sub-tropical-tropical coupling, we show that aerosol-driven sub-tropical rain suppression leads to increased advection of cold and moist air from the sub-tropics to the tropics, thus enhancing tropical cloudiness. The increased tropical cloudiness has a strong cooling effect by reflecting more of the incoming solar radiation. The classical “aerosol-cloud lifetime effect” is shown here to have a strong remote effect (sub-tropical aerosols increase cloudiness in the tropics), thus widening the concept of cloud adjustments to aerosol perturbation with important implications for marine cloud brightening.
  • seminar
    Date:
    27 March
    2024
    Wednesday
    Hours:
    11:00
    -
    12:00

    Exploring Inorganic and Organic Biomass for generation of Fuels and Chemical Commodities

    Location: Perlman Chemical Sciences Building
    São Paulo State University - UNESP

    Abstract

    Biomass is characterized as "material of biological origin, excluding material embedded in geological formations or fossilized." It serves as a valuable resource for energy production and as a foundational material for the synthesis of various commodity and specialty materials. The composition of biomass is notably more diverse and intricate than that of crude oil, resulting in significant distinctions between a conventional petroleum refinery and a biomass refinery, often referred to as a biorefinery. Unlike crude oil, which is typically abundant in gaseous, liquid, and solid hydrocarbons featuring a high carbon-to-oxygen (C/O) ratio, biomass primarily consists of complex biomacromolecules with a considerably lower C/O ratio. The conversion of biomass into commodity chemicals presents a promising approach to diminish society's reliance on fossil fuel resources—the predominant challenge of the 21st century. This challenge necessitates the development of tools and technologies to facilitate the transition from a predominantly petroleum-based to an alternative bio-based chemical industry. The objective of this seminar is to showcase the recent advancements we have made in enhancing bio-based platform molecules for the production of commodity or specialty chemicals. We achieve this through the utilization of C2 to C6 bio-based platforms, exemplified by polyols (e.g., glycerol), furanoids (e.g., furfural), and carboxylic acids (e.g., levulinic acid).
  • seminar
    Date:
    25 March
    2024
    Monday
    Hours:
    16:00

    EPS AI discussion seminar - Neural General Circulation Models for weather and climate predictions

    participants: Janni Yuval
  • seminar
    Date:
    21 March
    2024
    Thursday
    Hours:
    14:00
    -
    15:00

    Chemistry and the Information beyond the Genome Sequence

    Location: Gerhard M.J. Schmidt Lecture Hall
    participants: Prof. Andreas Marx
    Department of Chemistry and Konstanz Research School Chemical Biology, University of Konstanz Germany
  • seminar
    Date:
    20 March
    2024
    Wednesday
    Hours:
    11:00
    -
    12:00

    Employing the Hegelian Aufhebung Principle for Predicting New Catalytic Pathways

    Location: Perlman Chemical Sciences Building
    participants: Prof. Anatoly Frenkel
    Stony Brook University and Brookhaven National Laboratory

    Abstract

    Understanding mechanisms of work for a wide range of applied nanomaterials begins with identifying “active units” in operating conditions, zooming in on the “active sites” and ends with a model explaining their role for functioning of the material or device. There are two main hurdles that we are particularly interested in overcoming: 1) heterogeneity of active species and sites and 2) their dynamics that can be directly responsible for their mechanisms. One possible method, ideally suitable for capitalizing on these challenges for rational design of new catalytic pathways, is the Aufhebung (sublation) principle from the Hegelian dialectics. It describes the process of advancing knowledge by integrating the two opposites: the thesis and antithesis. We adopt this principle to leverage the inherent heterogeneity of catalytic active species and active sites in metal catalysts for understanding and predicting new catalytic pathways for CO and CO2 conversion reactions. Starting with atomically dispersed (the thesis) Pt on ceria support, we use multimodal, operando characterization for monitoring formation of nanoparticles (the antithesis), identify reaction active species and unique active sites at the metal-support interface. With this knowledge, we design the “single-atoms” catalysts (synthesis) possessing the same active sites and enhanced stability in reaction conditions. I will highlight the role of oxygen vacancies for enhancing the dynamicity of Pt atoms and opening new reaction pathways for direct and reverse water gas shift reactions and CO oxidation reaction.
  • seminar
    Date:
    19 March
    2024
    Tuesday
    Hours:
    14:00
    -
    15:00

    New approaches to glycan synthesis and glycan-based biosensing

    Location: Gerhard M.J. Schmidt Lecture Hall
    participants: Prof. Mattan Hurevich
    Institute of Chemistry Hebrew University
  • seminar
    Date:
    11 March
    2024
    Monday
    Hours:
    15:00

    EPS AI discussion seminar - Applications of Self Organizing Maps for the classification of cyclones in the Mediterranean

    Earth and Planetary Sciences Weizmann Institute of Science

    Abstract

    The use of SOM in atmospheric science has grown popular over the recent years. The SOM's strength lies in its ability to project the continuum of a given dynamical system to an easily understood spectrum of dominant states. The SOM relies on a neural network, where each grid-point in each node (cluster) is assigned with a specific weight for a given input parameter. The SOM then operates competitively, shifting individual members between the nodes to minimize internal node variability while maximizing the distances between the nodes. Here, two novel SOM applications are demonstrated, recently used to classify Mediterranean cyclones from an upper-level PV perspective. Each approach yields the potential to enhance the understanding of different aspects of Mediterranean cyclone's predictability and is readily applicable to other regions of interest.
  • seminar
    Date:
    10 March
    2024
    Sunday
    Hours:
    16:00
    -
    17:00

    Chemical and Biological Physics Guest seminar

    Location: Perlman Chemical Sciences Building
    participants: Prof. Oleg Vasyutinskii
    Peter the Great St. Petersburg Polytechnic University

    Abstract

    The lecture presents recent results obtained in the laboratory of Prof. Oleg Vasyutinskii in the Ioffe Institute, St.Petersburg, Russia along several directions of application of modern laser techniques for investigation of the dynamics of molecules relevant for biology and medicine. The particular directions under discussion will be as follows. • Investigation of energy transfer in the excited states of molecular probes in solutions by means of polarized fluorescence spectroscopy. • Pump-and-probe polarization modulation spectroscopy for investigation of sub-picosecond dynamics in excited biomolecules. • Dynamics of singlet oxygen generation and degradation in solutions and on organic surfaces.
  • seminar
    Date:
    5 March
    2024
    Tuesday
    Hours:
    14:00
    -
    15:00

    Machine learning for protein functional site annotation and peptide binder design

    Location: Gerhard M.J. Schmidt Lecture Hall
    participants: Dr. Jerome Tubiana
    Blavatnik School of Computer Science, Tel Aviv University
  • seminar
    Date:
    26 February
    2024
    Monday
    Hours:
    15:00

    EPS AI discussion seminar - Towards a Unified Conversational Model for Remote Sensing Imagery

    Location: Sussman Family Building for Environmental Sciences
    participants: Salman Khan (MBZUAI)
  • seminar
    Date:
    25 February
    2024
    Sunday
    Hours:
    11:00

    EPS Departmental Seminar; Challenges and opportunities in global storm resolving climate models

    Location: Sussman Family Building for Environmental Sciences
    Princeton University
  • seminar
    Date:
    20 February
    2024
    Tuesday
    Hours:
    14:00
    -
    15:00

    Principles of protein-protein interactions in 11 years of lab-evolution

    Location: Gerhard M.J. Schmidt Lecture Hall
    participants: Prof. Emmanuel Levy
    Dept. of Chemical and Structural Biology Weizmann Institute
  • seminar
    Date:
    12 February
    2024
    Monday
    Hours:
    15:00

    EPS AI discussion seminar- Machine Learning for Flood Forecasting: Research to Ope

    Location: Sussman Family Building for Environmental Sciences
    participants: Grey Nearing
  • seminar
    Date:
    11 February
    2024
    Sunday
    Hours:
    11:00

    The geologic history of marine dissolved organic carbon from iron (oxyhydr)oxides

    Location: Sussman Family Building for Environmental Sciences
    participants: Nir Galili
  • seminar
    Date:
    7 February
    2024
    Wednesday
    Hours:
    15:00
    -
    16:00

    Chemical and Biological Physics Guest seminar

    Location: Gerhard M.J. Schmidt Lecture Hall
    participants: Dr. Ron Tenne
    University of Konstanz

    Abstract

    While colloidal quantum dots (CQDs) are already an important building block in electro-optical devices, in the realm of quantum science and technology, they are often considered inferior with respect to emitters such as solid-state defects and epitaxial quantum dots. Despite their single-photon emission [1], demonstrations of quantum coherence and control are largely still lacking. The main obstacle towards these is spectral diffusion – stochastic fluctuations in the energy of photons emitted from an individual CQD even at cryogenic temperatures. In this talk, I will present our recent work providing, for the first time, direct and definitive proof that these fluctuations arise from stochastic electric fields in the particle’s nano environment [2]. However, the high sensitivity of CQDs to electric fields, through the quantum-confined Stark effect, can also be perceived as a feature, rather than a bug. I will present future concepts for coherent control of a single photon’s temporal wavefunction through an electric bias. Relying on tools from the terahertz and femtosecond-laser toolboxes [3,4], spectroscopy and control at fast-to-ultrafast (millisecond-to-femtosecond) timescales, will play a detrimental role in fulfilling the unique potential that CQDs hold in the field of quantum optics,. [1] R. Tenne, U. Rossman, B. Rephael, Y. Israel, A. Krupinski-Ptaszek, R. Lapkiewicz, Y. Silberberg, and D. Oron, Super-Resolution Enhancement by Quantum Image Scanning Microscopy, Nature Photonics 13, 116 (2019). [2] F. Conradt, V. Bezold, V. Wiechert, S. Huber, S. Mecking, A. Leitenstorfer, and R. Tenne, Electric-Field Fluctuations as the Cause of Spectral Instabilities in Colloidal Quantum Dots, Nano Lett. 23, 9753 (2023). [3] P. Henzler et al., Femtosecond Transfer and Manipulation of Persistent Hot-Trion Coherence in a Single CdSe/ZnSe Quantum Dot, Physical Review Letters 126, 067402 (2021). [4] P. Fischer, G. Fitzky, D. Bossini, A. Leitenstorfer, and R. Tenne, Quantitative Analysis of Free-Electron Dynamics in InSb by Terahertz Shockwave Spectroscopy, Physical Review B 106, 205201 (2022).
  • seminar
    Date:
    30 January
    2024
    Tuesday
    Hours:
    14:30
    -
    15:30

    Modeling protein complexes in the age of deep learning

    Location: Gerhard M.J. Schmidt Lecture Hall
    participants: Prof. Dina Schneidman
    School of Computer Science and Engineering The Hebrew University
  • seminar
    Date:
    17 January
    2024
    Wednesday
    Hours:
    11:00
    -
    12:00

    Design principles for new anode compositions: Exploring Earth-Abundant Transition Metal Oxides for Li-ion Batteries

    Location: Gerhard M.J. Schmidt Lecture Hall
    participants: Dr. Arava Zohar
    Materials Department and Materials Research Laboratory, University of California

    Abstract

    Innovative battery electrode materials are essential for unlocking the full potential of Li-ion batteries in various aspects of modern life. A primary focus is identifying novel materials with greater elemental diversity that offer improved stability, rapid charge capabilities, and high performance. Promising candidates, like early transition metal oxides, are earth-abundant and present opportunities for next-generation anode materials due to their redox voltage and more than a single stable oxidation state. Exploring fundamental design principles for improved de/lithiation mechanisms will influence battery functionality and advance energy storage capabilities. The first part will delve into the impact of the insulator-metal transition during lithiation, focusing on two distinctive Wadsley-Roth (WR) structures. Our findings underscore the critical role of disorder within these structures in determining kinetics and retained capacities for these anodes. The second part proposes a novel strategy leveraging the induction effect to reduce the operation voltage of Mo-oxide-based anodes. This reduction opens the door for Mo-based oxide anodes as an alternative to graphene. Understanding these key aspects can guide the search for alternatives to existing anodes for advancing the development of Li-ion batteries with enhanced performance in the energy storage field.
  • seminar
    Date:
    7 January
    2024
    Sunday
    Hours:
    15:00

    Chemical and Biological Physics Guest seminar

    Location: Gerhard M.J. Schmidt Lecture Hall
    participants: Dr Noam Shemesh
    Champalimaud Research Champalimaud Foundation, Lisbon

    Abstract

    In living systems, the tissue micro-architecture consists of myriad cellular and subcellular elements whose density, size/shape distributions, composition, and permeability, endow the tissue with its biological functionality. Dynamic transport mechanisms are further critical for maintaining homeostasis and supporting diverse physiological functions such as action potentials and biochemical signaling. Still, how these biophysical properties change over time and how they couple to activity, remains largely unknown. This is mainly due to the difficulty in mapping these properties in-vivo, longitudinally, and with sufficient specificity. Magnetic Resonance Imaging (MRI), with its capacity for longitudinal studies and wealth of microscopic information leading to multiple contrast mechanisms, provides an outstanding opportunity to decipher these phenomena. In this talk I will discuss our recent advances in diffusion and functional MRI, including novel pulse sequences and biophysical modeling of diffusion processes in the microscopic tissue milieu, which provide, for the first time, the sought-after specificity for density, size, and permeability of particular (sub)cellular elements in tissues. I will show new experiments in rodents proving unique power-laws predicted from biophysical models, revealing axon density and size, as well as cell body density and size, along with validations against ground-truth histology and applications in animal models of disease. Evidence for exchange between the intracellular and extracellular space will also be given, along with a first approach for quantitatively mapping permeability in tissue. I will also introduce correlation tensor MRI (CTI), a new approach for source-separation in diffusional kurtosis, that offers surrogate markers of neurite beading effects, thereby further enhancing specificity, especially in stroke. Finally, I will touch upon dynamic modulations of neural tissue microstructure upon neural activity, and provide evidence for the existence of a neuro-morphological coupling in diffusion-weighted functional MRI signals. Future vistas and potential applications will be discussed.
  • seminar
    Date:
    3 January
    2024
    Wednesday
    Hours:
    15:00
    -
    16:00

    Chemical and Biological Physics Guest seminar

    Location: Gerhard M.J. Schmidt Lecture Hall
    participants: Dr Ran Finkelstein
    Caltech

    Abstract

    Large arrays of trapped neutral atoms have emerged over the past few years as a promising platform for quantum information processing, combining inherent scalability with high-fidelity control and site-resolved readout. In this talk, I will discuss ongoing work with arrays of Alkaline-earth atoms. These divalent atoms offer unique properties stemming largely from their long-lived metastable states, which form the basis of the optical atomic clock. I will describe the design of a universal quantum processor based on clock qubits and its application in quantum metrology, and I will address the challenge of generating and benchmarking highly entangled states in an analog quantum simulator. First, we realize scalable local control of individual clock qubits, which we utilize to extend the Ramsey interrogation time beyond the coherence time of a single atom [1]. To realize a universal quantum processor, we demonstrate record high-fidelity two-qubit entangling gates mediated by Rydberg interactions, which we combine with dynamical reconfiguration to entangle clock probes in GHZ states and perform Ancilla-based detection [2]. We then use the narrow clock transition to measure and remove thermal excitations of atoms in tweezers (a technique known as erasure conversion) and generate hyperentangled states of motion and spin [3]. In the second part of the talk, I will describe a different approach for generating large scale entangled states in an analog quantum simulator configuration [4], including error mitigation [5] and benchmarking of a 60-atom simulator [6]. Together, these show the great promise and the large variety of experiments accessed with this emerging platform. [1] A. Shaw*, R. Finkelstein*, R. Tsai, P. Scholl, T. Yoon, J. Choi, M. Endres, Multi-ensemble metrology by programming local rotations with atom movements, arxiv:2303.16885, Nature Physics in press (2023). [2] R. Finkelstein, R. Tsai, A. Shaw, X. Sun, M. Endres, A universal quantum processor for entanglement enhanced optical tweezer clocks, in preparation. [3] P. Scholl*, A. Shaw*, R. Finkelstein*, R. Tsai, J. Choi, M. Endres, Erasure cooling, control, and hyper-entanglement of motion in optical tweezers, arXiv:2311.15580 (2023). [4] J. Choi, A. Shaw, I. Madjarov, X. Xie, R. Finkelstein, J. Covey, J. Cotler, D. Mark, H.Y. Huang, A. Kale, H. Pichler, F. Brandão, S. Choi, and M. Endres, Preparing random states and benchmarking with many-body quantum chaos, Nature 617 (2023) [5] P. Scholl, A. Shaw, R. Tsai, R. Finkelstein, J. Choi, M. Endres, Erasure conversion in a high-fidelity Rydberg quantum simulator, Nature 622 (2023). [6] A. Shaw, Z. Chen, J. Choi, D.K. Mark, P. Scholl, R. Finkelstein, A. Elben, S. Choi, M. Endres, Benchmarking highly entangled states on a 60-atom analog quantum simulator, arXiv:2308.07914 (2023).
  • seminar
    Date:
    2 January
    2024
    Tuesday
    Hours:
    11:15
    -
    12:15

    Enhanced Growth in Atomic Layer Deposition of Transition Metals: The Role of Surface Diffusion and Nucleation Sites

    Location: Gerhard M.J. Schmidt Lecture Hall
    participants: Dr. Amnon Rothman
    Chemical Engineering, Stanford University

    Abstract

    Noble metal thin films have attracted significant interest owing to their distinctive properties and structures, which make them ideal for applications in microelectronics, catalysis, energy, and photovoltaics. While several parameters influence the properties of these metals for such applications, the deposition process remains a critical factor. Atomic Layer Deposition (ALD) stands out as a prevalent deposition technique due to its surface-sensitive nature. The ALD process is characterized by its self-limiting surface reactions, promoting a layer-by-layer growth mechanism and allowing for precise control over film thickness and conformality. However, challenges arise in achieving continuous, pinhole-free noble metal ALD layers on oxide surfaces, often resulting in low film quality. These challenges can be traced back to the lack of adequate nucleation sites and the poor wettability of the low-surface energy substrates. The research studied the impact of substrate surface functionalization using organometallic molecules, such as trimethylaluminum (TMA) and diethylzinc (DEZ), on the nucleation and growth of Ru layers. The results reveal an enhancement in both nucleation density and the average diameter of the Ru nanoparticles deposited, and these improvements were attributed to an increase in both nucleation sites and elevated surface diffusivity. The latter effect is speculated to result from a reduction in the substrate's surface free energy. The study also examines the influence of substrate surface characteristics, including surface termination and crystallinity, on the nucleation and growth of Ru metal via ALD. The morphologies of the resulting Ru thin films are studied using scanning electron microscopy (SEM), atomic force microscopy (AFM), and grazing incidence small angle x-ray scattering (GISAXS). These analytical results are integrated with an experimental model to elucidate the differences in growth mechanisms observed across substrates. The findings underscore the importance of substrate choice in the ALD process and broaden our understanding of Ru metal growth. This research serves as an important step in optimizing the ALD process for various applications by tailoring substrate selection.
  • seminar
    Date:
    26 December
    2023
    Tuesday
    Hours:
    14:00
    -
    15:00

    The structure of protein complexes underlies co-translational assembly

    Location: Gerhard M.J. Schmidt Lecture Hall
    participants: Dr. Saurav Mallik
    Prof. Emmanuel Levy's lab Dept. of Chemical & Structural Biology WIS
  • seminar
    Date:
    26 November
    2023
    Sunday
    Hours:
    11:00

    Cancelled

    Location: Sussman Family Building for Environmental Sciences
    participants: Jianmin Chen
  • seminar
    Date:
    19 November
    2023
    Sunday
    Hours:
    11:00
    -
    12:00

    cancelled

    Location: Sussman Family Building for Environmental Sciences
    participants: Erwin Zehe
  • seminar
    Date:
    5 November
    2023
    Sunday
    Hours:
    11:00

    TBA

    Location: Sussman Family Building for Environmental Sciences
    participants: Paul O'Gorman
  • seminar
    Date:
    17 October
    2023
    Tuesday
    Hours:
    11:00

    Chemical and Biological Physics Guest seminar

    Location: Gerhard M.J. Schmidt Lecture Hall
    participants: Prof. Timur O. Shegai,Terry Debesh
    Chalmers University of Technology, Sweden

    Abstract

    Strong light-matter interactions are at the core of many electromagnetic phenomena. In this talk, I will give an overview of several nanophotonic systems which support polaritons – hybrid light-matter states, as well as try to demonstrate their potential usefulness in applications. I will start with transition metal dichalcogenides (TMDs) and specifically discuss one-dimensional edges in these two-dimensional materials (1-2). I will show that TMDs can be etched along certain crystallographic axes, such that the obtained edges are nearly atomically sharp and exclusively zigzag-terminated, while still supporting polaritonic regime. Furthermore, I will show that Fabry-Pérot resonators, one of the most important workhorses of nanophotonics, can spontaneously form in an aqueous solution of gold nanoflakes (3-4). This effect is possible due to the balance between attractive Casimir-Lifshitz forces and repulsive electrostatic forces acting between the flakes. There is a hope that this technology is going to be useful for future developments in self-assembly, nanomachinery, polaritonic devices, and perhaps other disciplines. References: 1) Nat. Commun., 11, 4604, (2020) 2) Laser & Photonics Rev., 17, 2200057, (2023) 3) Nature 597, 214-219, (2021) 4) Nat. Phys. 19, 271-278, (2023)
  • seminar
    Date:
    15 October
    2023
    Sunday
    Hours:
    11:00

    TBA

    Location: Sussman Family Building for Environmental Sciences
    participants: Dr. Katinka Bellomo
  • seminar
    Date:
    19 September
    2023
    Tuesday
    Hours:
    14:00
    -
    15:00

    How did the protoribosomes form the first peptide bonds – chemical and structural studies

    Location: Gerhard M.J. Schmidt Lecture Hall
    participants: Dr. Tanaya Bose
    Yonath Lab, Dept. of Chemical and Structural Biology, Weizmann Institute
  • seminar
    Date:
    14 September
    2023
    Thursday
    Hours:
    11:00

    Chemical and Biological and Ben May Seminar

    Location: Perlman Chemical Sciences Building
    participants: Prof. Cheol Ho Choi
    Kyungpook National University, South Korea

    Abstract

    A new quantum theory, MRSF-TDDFT (Mixed-Reference Spin-Flip Time-Dependent Density Functional Theory) has been developed*, which introduces the multi-reference advantages within the linear response formalism. The density functional theory (DFT) and linear response (LR) time dependent (TD)-DFT are of utmost importance for routine computations. However, the single reference formulation of DFT is suffering from the description of open-shell singlet systems such as diradicals and bond-breaking. LR-TDDFT, on the other hand, finds difficulties in the modeling of conical intersections, doubly excited states, and core-level excitations. Many of these limitations can be overcome by MRSF-TDDFT, providing an alternative yet accurate route for such challenging situations. Now the theory is combined with NAMD, QM/MM, Spin-Orbit Couplings, and Extended Koopman Theorem. Here, we highlight its performances by presenting our recent results by MRSF-TDDFT especially focusing on nonadiabatic molecular dynamics.
  • seminar
    Date:
    10 September
    2023
    Sunday
    Hours:
    11:00

    Quantifying the Global and Regional Contribution of Terrestrial Carbon Pools to the Land Sink

    Location: Sussman Family Building for Environmental Sciences
    participants: Yinon Bar-On
    California Institute of Technology

    Abstract

    Terrestrial sequestration of carbon has mitigated ≈30% of anthropogenic carbon emissions. However its distribution across different pools—live or dead biomass, and soil and sedimentary organic carbon— which has important implications for future climate change mitigation, remains uncertain. By analyzing global observational datasets of changes in terrestrial carbon pools, we are able to partition carbon that has been sequestered on land between 1992-2019 into live biomass and non-living organic carbon pools. We compare our observation-based estimates against predictions of global vegetation models and identify key processes that are not included in most models that can help align the models with observations. We find that most terrestrial carbon gains are sequestered as non-living organic matter, and thus more persistent than previously appreciated, with a substantial fraction linked to human activities such as river damming, wood harvest, and garbage disposal in landfills.
  • seminar
    Date:
    7 September
    2023
    Thursday
    Hours:
    11:00
    -
    12:00

    “Lessons From Nature: How to Get the Best out of Materials”

    Location: Gerhard M.J. Schmidt Lecture Hall
    participants: Prof. Mato Knez
    Ikerbasque, Basque Foundation for Science

    Abstract

    Processes in nature are often long-lasting, but they have a common goal, i.e., to advance structures or constructions. Especially for the composition of materials, it is worth having a closer look and mimic the natural concept for improving the properties of the known materials and in this way opening doors for new application fields. Among the concepts in nature there is the hybridization of materials, i.e., the blend of organic and inorganic materials with the goal of outperforming both constituting components. The engineering of such hybrid materials can be done in synthetic wet-chemical or in physical ways and often the results, i.e., the properties of the materials, will differ, even if their composition is identical. This may result from different qualities of interactions between the constituting materials. The quality of interactions can be controlled by the choice of the chemicals and/or the choice of hybridization process. Two recently developed approaches for hybridization base on vapor phase chemistry and are derived from atomic layer deposition (ALD) and result in hybrid thin film growth (molecular layer deposition, MLD) or subsurface hybridization of polymers (vapor phase infiltration, VPI). Both approaches open a plethora of new options for materials design for future applications. In this talk, some approaches of our group will be discussed that show great promise of vapor phase-grown hybrid films for innovation in technological fields beyond the microelectronics industry. Examples, where mechanical and electronic properties of polymeric materials have been significantly improved through nanoscale coatings and infiltration, will be shown. Furthermore, new concepts towards self-healing of semiconducting thin films, enabled by hybrid materials, will be shown. In most cases, the chemical or physical properties of the initial substrate are altered, typically improved, and new functionalities are added.
  • seminar
    Date:
    30 August
    2023
    Wednesday
    Hours:
    11:00
    -
    12:00

    Ultra-Repellent Aerophilic Surfaces Underwater”

    Location: Gerhard M.J. Schmidt Lecture Hall
    participants: Dr. Alexander B. Tesler
    Friedrich-Alexander-Universität Erlangen-Nürnberg, Germany

    Abstract

    Wetting describes the ability of liquids to maintain contact with a solid surface, a phenomenon that is ubiquitous in nature.1 However, in engineering and medical applications, contact of solid surfaces with aqueous media leads to undesirable phenomena such as corrosion, chemo- and biofouling, which have extremely negative economic, health, and environmental impacts. Therefore, control of wetting on solid surfaces is key to mitigating its detrimental effects. The latter can be achieved by minimizing the contact of the solid substrate with aqueous media, so-called superhydrophobic surfaces (SHS). Although SHS have been studied for decades to overcome wetting challenges,2 they are still rarely used in engineering applications. When immersed underwater, a special type of SHS can trap air on its surface, so-called air plastron, also known as an aerophilic surface. To date, plastrons have been reported to be impractical for underwater engineering due to their short lifetime. Here, I will describe aerophilic surfaces made of titanium alloy (Ti) with an extended lifetime of plastron conserved for months underwater.3 The extended methodology was developed to unambiguously describe the wetting regime on such aerophilic surfaces since conventional goniometric measurements are simply impractical. My aerophilic surfaces drastically reduce the adhesion of blood, and when immersed in aqueous media, prevent the adhesion of bacteria, and marine organisms such as barnacles, and mussels. Applying thermodynamic stability theories, we describe a generic strategy to achieve long-term stability of plastron on aerophilic surfaces for demanding and hitherto unattainable applications. (1) Quéré, D. Wetting and Roughness. Annual Review of Materials Research 2008, 38 (1), 71-99. (2) Cassie, A. B. D.; Baxter, S. Wettability of porous surfaces. Transactions of the Faraday Society 1944, 40, 546-551. (3) Tesler, A.B.;* Kolle, S.; Prado, L.H.; Thievessen, I.; Böhringer, D.; Backholm, M.; Karunakaran, B.; Nurmi, H.A.; Latikka, M.; Fischer, L.; Stafslien, S.; Cenev, Z.M.; Timonen, J.V.I.; Bruns, M.; Mazare, A.; Lohbauer, U.; Virtanen, S.; Fabry, B.; Schmuki, P.; Ras, R.H.A.; Aizenberg, J.; Goldmann, W.H. Long-Lasting Aerophilic Metallic Surfaces Underwater. Nature Materials 2023, accepted. *Corresponding author
  • seminar
    Date:
    15 August
    2023
    Tuesday
    Hours:
    14:00
    -
    15:00

    Intra-host evolution of HIV env after broadly-neutralizing antibody infusion

    Location: Gerhard M.J. Schmidt Lecture Hall
    participants: Dr. Frida Belinky
    Virus Persistence and Dynamics Section Immunology Laboratory Vaccine Research Center National Institute of Allergy and Infectious Diseases National Institutes of Health
  • seminar
    Date:
    23 July
    2023
    Sunday
    Hours:
    11:00

    Using weather regimes in the context of sub-seasonal forecasting for the Extratropics: the role of synoptic-scale processes in regime predictability, modulation by the MJO and stratosphere, and link to surface weather

    participants: Christian Grams
    Karlsruhe Institute of Technology

    Abstract

    Sub-seasonal forecasting aims to predict the mean weather conditions on weekly time-scales 2-6 weeks ahead. In the midlatitudes, lLarge-scale, quasi-stationary, recurrent, and persistent flow patterns, so-called weather regimes, explain sub-seasonal weather variability in the European region. However, forecast skill and predictability for regimes are mostly very poor on sub-seasonal forecast horizons. In this presentation we shed light on how synoptic-scale processes, affect the predictability and forecast skill of North Atlantic-European weather regimes. We focus on the upper-tropospheric divergent outflow due to latent heat release in ascending air streams, so-called warm conveyor belts (WCBs). We find evidence that a misrepresentation of diabatic WCB outflow at onset of regimes characterised by blocking anticyclones is likely the cause for vanishing regime skill on sub-seasonal time scales. At the same time results suggest that a correct representation of WCB activity might be a window of forecast opportunity for regimes. We further discuss how the occurrence of regimes is modulated by the state of the winter stratosphere and the MJO, which provide another window of forecast opportunity for weather regimes on sub-seasonal time scales. Interestingly, we find again that WCB activity related to synoptic-scale weather systems modulate the MJO teleconnections towards North America and Europe. We conclude that knowledge about physical and dynamical processes on synoptic scales is key for exploiting the potential windows of forecast opportunity for weather regimes on sub-seasonal time scales.
  • seminar
    Date:
    20 July
    2023
    Thursday
    Hours:
    11:00
    -
    12:00

    Solvent-Enhanced Symmetry-breaking and Singlet-Fission in the Covalently-Bound Tetracene Dimer and Calculation of Electronic States in TIPS-Pentacene

    Location: Gerhard M.J. Schmidt Lecture Hall
    participants: Prof. Hans Lischka
    Department of Chemistry & Biochemistry Texas Tech University

    Abstract

    In recent years, covalently bound dimers of chromophores have attracted significant interest as singlet fission (SF) material because of better control of coupling of different electronic states to the gateway 1(TT) by means of intramolecular vibrational modes.1 It has been shown that charge transfer (CT) plays a crucial role in mediating the S1-1(TT) interaction and their influence can be conveniently tuned by solvent polarity. Motivated by the experimental and theoretical work of Alvertis et al.,1 we have investigated the electronic states relevant to the SF for the covalently bound tetracene dimer with the goal to provide a broader picture of the occurring photodynamical processes.2 For that purpose, the second-order algebraic diagrammatic construction (ADC(2)) method in combination with the conductor-like screening model (COSMO) has been used. Vertical excitations and potential energy curves for excitonic and CT states along low-frequency symmetric and antisymmetric normal modes have been computed. These results have been combined with those obtained by density functional theory/multireference configuration interaction (DFT/MRCI) calculations for the 1(TT) state since its doubly-excited wavefunction is not accessible to the ADC(2) method. In the second part of the talk, DFT/MRCI calculations on dimer and trimer TIPS-Pn will be presented with the goal of a first theoretical understanding of the photodynamics of the 1(TT) state monitored by time-resolved mid-IR absorption spectroscopy.3
  • seminar
    Date:
    11 July
    2023
    Tuesday
    Hours:
    11:00
    -
    12:00

    Unconventional semiconductors and device architectures enabled by molecular design, doping and film morphology engineering

    Location: Gerhard M.J. Schmidt Lecture Hall
    participants: Prof. Antonio Facchetti
    Department of Chemistry and the Materials Research Center, Northwestern University

    Abstract

    Organic/printed electronics is a technology enabling the fabrication of mechanically flexible/stretchable electronic circuits and devices using low-temperature, possibly by additive, solution processing methodologies. In this presentation we report the development of novel materials, as well as thin-film processing and morphology engineering, for flexible and stretchable organic and inorganic thin film transistors, electrolyte gated transistors and circuits. On material development, we present that “soft” small-molecules and polymers can be synthesized by co-polymerizing naphthalenediimide (NDI) or diketopyrrolopyrrole (DPP) units with proper co-monomer building blocks or properly designed additives. Furthermore, we also report the fabrication of stretchable inorganic metal oxide fiber network by spry coating metal salts+thermally labile polymer formulations. New transistor architectures using semiconductor film porosity as the key element for enhancing mechanical flexibility and tune charge transport are also demonstrated. These films, combined with elastomeric pre-stretching, enables unprecedentedly stable current-output characteristic upon mechanical deformation, which are used for sensing analytes, strain, light, temperature and physiological parameters. Finally, we report our recent work on molecular n-doping of organic semiconductors using a novel strategy involving catalysts.
  • seminar
    Date:
    9 July
    2023
    Sunday
    Hours:
    11:00

    A Neolithic Tsunami Event along the Eastern Mediterranean Littoral: A Transdisciplinary Research at the Coast of Dor Israel

    Location: Sussman Family Building for Environmental Sciences
    participants: Gilad Steinberg
    University of California San Diego

    Abstract

    Tsunami events in antiquity had a profound influence on coastal societies. Six thousand years of historical records and geological data show that tsunamis are a common phenomenon affecting the eastern Mediterranean coastline. However, the possible impact of older tsunamis on prehistoric societies has not been investigated. Here we report, based on optically stimulated luminescence chronology, the earliest documented Holocene tsunami event, between 9.91 to 9.29 ka (kilo-annum), from the eastern Mediterranean at Dor, Israel. Tsunami debris from the early Neolithic is composed of marine sand embedded within fresh-brackish wetland deposits. Global and local sea-level curves for the period, 9.91–9.29 ka, as well as surface elevation reconstructions, show that the tsunami had a run-up of at least ~16 m and traveled between 3.5 to 1.5 km inland from the palaeo-coastline. Submerged slump scars on the continental slope, 16 km west of Dor, point to the nearby “Dor complex” as a likely cause. The near absence of Pre-Pottery Neolithic A-B archaeological sites (11.70–9.80 cal. ka) suggests these sites were removed by the tsunami, whereas younger, late Pre-Pottery Neolithic B-C (9.25–8.35 cal. ka) and later Pottery-Neolithic sites (8.25–7.80 cal. ka) indicate resettlement following the event. The significant run-up of this event highlights the disruptive impact of tsunamis on past societies along the Levantine coast.
  • seminar
    Date:
    27 June
    2023
    Tuesday
    Hours:
    14:00
    -
    15:00

    Functional studies of lysine ac(et)ylation using genetically encoded post-translational modifications

    Location: Gerhard M.J. Schmidt Lecture Hall
    participants: Prof. Eyal Arbely
    Department of Chemistry Ben Gurion University
  • seminar
    Date:
    22 June
    2023
    Thursday
    Hours:
    11:00
    -
    12:00

    Quo Vadis Small Molecule Drug Discovery?

    Location: Gerhard M.J. Schmidt Lecture Hall
    participants: Dr. Ingo Hartung
    Head of Medicinal Chemistry & Drug Design Global Research & Development Merck Healthcare KGaA
  • seminar
    Date:
    18 June
    2023
    Sunday
    Hours:
    11:00
    -
    12:00

    TBA

    Location: Sussman Family Building for Environmental Sciences
    participants: Tal Benaltabet
    The Hebrew University of Jerusalem
  • seminar
    Date:
    15 June
    2023
    Thursday
    Hours:
    11:00

    Chemical and Biological Physics Guest Seminar

    Location: Gerhard M.J. Schmidt Lecture Hall
    participants: Dr Gideon Segev
    School of Electrical Engineering, Tel Aviv University

    Abstract

    Even though highly selective ion pumps can be found in every living cell membrane, artificial, membrane-based ion selective separation is a longstanding unmet challenge in science and engineering. The development of a membrane-based ion separation technology can drive a dramatic progress in a wide range of applications such as: water treatment, bio-medical devices, extraction of precious metals from sea water, chemical sensors, solar fuels and more. In this seminar I will discuss our theoretical and experimental demonstration of ion pumps based on an electronic flashing ratchet mechanism. Electronic flashing ratchets are devices that utilize modulation in a spatially varying electric field to drive steady state current. Like peristaltic pumps, where the pump mechanism is not in direct contact with the pumped fluid, electronic ratchets induce net current with no direct charge transport between the power source and the pumped charge carriers. Thus, electronic ratchets can be used to pump ions in steady state with no electrochemical reactions between the power source and the pumped ions resulting in an “all electric” ion pump. Ratchet-based ion pumps (RBIPs) were fabricated by coating the two surfaces of nano-porous alumina wafers with gold forming nano-porous capacitor-like devices. The electric field within the nano-pores is modulated by oscillating the capacitors voltage. Thus, when immersed in solution, ions within the pores experience a modulating electric field resulting in ratchet-based ion pumping. The RBIPs performance was studied for various input signals, geometries, and solutions. RBIPs were shown to drive ionic current densities of several μA/cm2 even when opposed by an electrostatic force. A significant ratchet action was observed with input signal amplitudes as low as 0.1V thus demonstrating that RBIPs can drive an ionic current with no associated redox reactions. Simulations show that frequency dependent flux inversions in ratchet systems may pave the way towards ion selective RBIPs.
  • seminar
    Date:
    15 June
    2023
    Thursday
    Hours:
    00:00

    “Parahydrogen Enhanced Magnetic Resonance - a tale of spin physics, materials and catalysis”

    Location: Gerhard M.J. Schmidt Lecture Hall
    participants: Dr. Stefan Glogger
    Max Plank Institute for Multidisciplinary Sciences, Gottingen

    Abstract

    Catalysts are essential in increasing reaction rates of chemical reactions. They have not only shaped our modern world but are also used by nature in many biochemical reactions. Understanding catalytic mechanisms and developing new catalysts holds promise to e.g. solve energy challenges of our society. Before this background, I am developing new methodologies based on magnetic resonance to unravel processes in catalysis and work towards nano-materials in which nuclear spin states can be controlled during reactions. Thereby, I am making use of the technique of parahydrogen induced polarization, which is an enhancement technology in NMR, boosting signals by four orders of magnitude. This approach uses parahydrogen, a spin isomer of normal hydrogen gas that interacts with a catalyst and undergoes a chemical reaction. During this process, the spin order of parahydrogen is converted into largely enhanced magnetic resonance signals and acts as a spy molecule for the catalytic process. In recent years my group has pioneered the use of parahydrogen to study metalloenzymes and more in specific hydrogenases. Hydrogenases are considered nature's blueprint for efficient hydrogen activation catalysts. Although they represent an important class of enzymes, the catalytic mechanisms leading to hydrogen activation are not fully understood. My developed tools allowed for new insights that no other analytical technology could provide and thereby refined details of the catalytic mechanisms. Additionally, my group has been researching the development of nano-catalysts that can allow for maintaining the para-hydrogen spin order on surfaces. This promises on one side to develop new enhancement strategies in particular to boost the signal of mobile protons that can e.g. exchange with proteins or small molecules leading to their further enhancements in solution. On the other side, a precise control of nuclear spin states during chemical reactions in solution can allow for the future production of large quantities of spin-controlled chemicals such as para-water or formaldehyde in the para-state. These are chemicals found in e.g. interstellar clouds showing different ratios between ortho (triplet) and para (singlet) states as compared to earth and are thought to display different reactivities. Understanding the effect of nuclear spin states on reactions could lead to new application in chemical reactions and catalysis in the future.
  • seminar
    Date:
    13 June
    2023
    Tuesday
    Hours:
    14:00
    -
    15:00

    Translational Chemical Biology

    Location: Gerhard M.J. Schmidt Lecture Hall
    participants: Prof. Xiaoguang Lei
    Peking University
  • seminar
    Date:
    13 June
    2023
    Tuesday
    Hours:
    10:00
    -
    11:00

    Joint Chemical and Biological Physics and Molecular Chemistry and Materials Science Guest Seminar

    Location: Gerhard M.J. Schmidt Lecture Hall
    participants: Dr Yair Litman
    University of Cambridge

    Abstract

    ydrogen transfer reactions play a prominent role in nature and many technological applications. Despite appearing to be simple reactions, they constitute complex processes where nuclear quantum effects (NQE) such as zero-point energy and nuclear tunneling play a decisive role even at ambient temperature. In this talk, I will show how state-of-the-art methodologies based on the path integral formulation of quantum mechanics in combination with the density functional approximation provide the unique possibility to theoretically address these effects in complex environments. The first part of the talk will focus on the porphycene molecule in the gas phase and adsorbed on metallic surfaces. The porphycene molecule constitutes a paradigmatic example of a molecular switch and has recently received great attention due to its intriguing hydrogen dynamics. I will demonstrate how a correct treatment of NQE, as well as the inclusion of multidimensional anharmonic couplings, are essential to obtain qualitatively correct results regarding the non-trivial temperature dependence of the hydrogen transfer rates and vibrational spectra [1-3]. Finally, I shall also mention some of our recent results for hydrogen diffusion on metals for which non-adiabatic effects, in addition to NQE, play a significant role and can lead to “quantum localization” [4-6]. [1] Y. Litman, J. O. Richardson, T. Kumagai, and M. Rossi, J. Am. Chem. Soc. 141, 2526 (2019) [2] Y. Litman, J. Behler, and M. Rossi, Faraday Discuss. 221, 526 (2020) [3] Y. Litman and M. Rossi, Phys. Rev. Lett. 125, 216001 (2020) [4] Y. Litman, E. S. Pos. C. L. Box, R. Martinazzo, R. J. Maurer, and M. Rossi, J. Chem. Phys. 156, 194106 (2022) [5] Y. Litman, E. S. Pos. C. L. Box, R. Martinazzo, R. J. Maurer, and M. Rossi , J. Chem. Phys. 156, 194107 (2022) [6] O. Bridge, R. Martinazzo, S. C. Althorpe, Y. Litman, in preparation (2023)
  • seminar
    Date:
    11 June
    2023
    Sunday
    Hours:
    11:00
    -
    12:00

    Soft Matter and Biomaterials: Membrane remodelling in viral infection and migrasome formation

    Location: Perlman Chemical Sciences Building
    participants: Dr. Raya Sorkin
    School of Chemistry, TAU

    Abstract

    Fundamental understanding of physiological processes that occur at biological membranes, such as membrane fusion, necessitates addressing not only the biochemical aspects, but also biophysical aspects such as membrane mechanical properties and membrane curvature. In this talk, I will show how we combine membrane model systems, micropipette aspiration, optical tweezers and confocal fluorescence microscopy to study membrane shaping and membrane fusion processes. I will describe a new tool we developed, where we form membrane bilayers supported on polystyrene microspheres which can be trapped and manipulated using optical tweezers. Using this approach, we demonstrate successful measurements of the interaction forces between the Spike protein of SARS CoV-2 and its human receptor, ACE2. We further use bead-supported membranes interacted with aspirated vesicles to reveal the inhibitory effect of membrane tension on hemifusion. I will also describe a particular case of membrane shaping during the formation of the newly discovered organelle termed migrasome. We show that tetraspanin proteins involved in migrasome formation strongly partition into curved membrane tethers, and we reveal a novel, two-step process of migrasome biogenesis.
  • seminar
    Date:
    11 June
    2023
    Sunday
    Hours:
    11:00
    -
    12:00

    TBA

    Location: Sussman Family Building for Environmental Sciences
    participants: Yael Leshno
  • seminar
    Date:
    11 June
    2023
    Sunday
    Hours:
    10:00
    -
    11:00

    Probing nanocrystal photophysics with spectator excitons

    Location: Gerhard M.J. Schmidt Lecture Hall
    participants: Prof. Sanford Ruhman
    Institute of Chemistry, HUJI

    Abstract

    Femtosecond pump-probe experiments on nanocrystals are interpreted primarily in terms of state filling of the states involved in the intense band edge absorption features, and bi-exciton shifting which changes the resonance energy of the probe pulse due to presence of pump induced excitations. Results have been interpreted to show 1) that “hot” excitons will relax to the lowest available levels in the conduction band in ~1 ps, and 2) that said intense band edge exciton transition will be bleached linearly with excitons until the underlying states are completely filled. In the talk we describe a new approach involving “spectator excitons” to test these accepted views. It consists of comparing pump-probe experiments on pristine samples, with equivalent scans conducted on the same sample after it has been saturated in cold mono-excitons. We show how this method has uncovered previously unrecognized spin blockades in the relaxation of hot multi-exciton states in CdSe NCs, and simply detects stimulated emission signals even in presence of overlapping absorption. We report specific difficulties of applying this approach on perovskite crystals leading to controversial determination that in quantum confined CsPbBr3 bi-exciton interactions are positive (repulsive) and describe recent time resolved emission data which challenges this result.
  • seminar
    Date:
    7 June
    2023
    Wednesday
    Hours:
    10:30
    -
    11:30

    “How atoms jiggle and wiggle in energy materials”

    Location: Gerhard M.J. Schmidt Lecture Hall
    participants: Prof. David Egger
    Dept. Physics, Technical University of Munich

    Abstract

      Energy materials are crystalline, solid-state substances with technological applications in energy-conversion or storage devices that include solar cells and batteries. In our work, we are particularly interested in scenarios where these systems show unusual structural dynamical effects. These effects trigger many puzzling questions in regard to updated structure-property relations and improved theoretical understandings of these solids. In my talk, I will present our recent findings regarding theoretical treatments of structural dynamics in energy materials and how we may use them to improve our understanding of their finite-temperature properties. The results will focus on halide perovskite as well as nitride semiconductors and solid-state ion conductors, which we typically investigate in tandem with experiment.
  • seminar
    Date:
    6 June
    2023
    Tuesday
    Hours:
    14:00
    -
    15:00

    Microbiome Metabolites: Syntheses and Surprises

    Location: Gerhard M.J. Schmidt Lecture Hall
    participants: Prof. Karl Gademann
    Department of Chemistry University of Zurich
  • seminar
    Date:
    6 June
    2023
    Tuesday
    Hours:
    10:00
    -
    11:00

    Chemical and Biological Physics Guest Seminar

    Location: Perlman Chemical Sciences Building
    participants: Prof Magali Lingenfelder
    Max Planck-EPFL Laboratory for Molecular Nanoscience and Technology, Ecole Polytechnique Federale de Lausanne (EPFL)

    Abstract

    Our society faces a critical challenge in shifting from a reliance on carbon-based energy to sustainable renewable sources. A key step towards achieving clean energy lies in developing efficient catalysts that can convert chemical energy into electricity or use electrons to generate chemical energy. In our research group, we tackle these challenges by creating customized materials that draw inspiration from nature (biomimicry) and combine principles from interfacial chemistry and surface physics. For this presentation, I focus on the process of photosynthesis as inspiration for the design, characterization, and dynamic nature of functional interfaces that drive energy conversion processes such as CO2 electroreduction and water splitting. I will also discuss the application of cutting-edge scanning probe microscopy, which allows us to visualize dynamic electrochemical processes at the nanoscale (operando imaging). Additionally, I will highlight our use of unconventional strategies that leverage chiral molecules and abundant two-dimensional materials to enhance electrocatalytic conversion processes. (References : Nanoletters, 2021, 21, 2059; Nature Comm., 2022, 13, 3356, IJC 62, 11, 2022).
  • seminar
    Date:
    4 June
    2023
    Sunday
    Hours:
    11:00
    -
    12:00

    Paleoclimate reconstruction using speleothems in dry and cold regions.

    Location: Sussman Family Building for Environmental Sciences
    participants: Anton Vaks
    GSI, Israel
  • seminar
    Date:
    1 June
    2023
    Thursday
    Hours:
    14:00
    -
    15:00

    Ben May Lecutre Series

    Location: Stone Administration Building
    participants: Prof Nancy Makri
    University of Illinois at Urbana-Champaign

    Abstract

    The interplay among electronic coherence, vibrational damping, quantum dispersion, topological effects and thermal fluctuations leads to rich behaviors in the dynamics of excitation energy flow. We use real-time path integral methods developed in our group to perform fully quantum mechanical simulations of excitation energy transfer in large molecular aggregates. The systems are described through a Frenkel exciton Hamiltonian where all vibrational normal modes of each molecular unit and their coupling to the ground and excited electronic states are treated explicitly at any temperature. Simulations have been carried out in J aggregates of perylene bisimide, model dendrimers, and photosynthetic light harvesting complexes. Coherence maps offer powerful visualization tools that reveal the creation and destruction of quantum superpositions and enable a state-to-state pathway analysis of energy flow.
  • seminar
    Date:
    30 May
    2023
    Tuesday
    Hours:
    14:00
    -
    15:00

    Electrosome assembly: a first look at the structural principles underlying ion channel biogenesis

    Location: Gerhard M.J. Schmidt Lecture Hall
    participants: Prof. Daniel Minor
    Departments of Biochemistry & Biophysics University of California San Francisco
  • seminar
    Date:
    30 May
    2023
    Tuesday
    Hours:
    11:00
    -
    12:00

    Homogeneous (De)hydrogenative Catalysis for a Circular Economy

    Location: Gerhard M.J. Schmidt Lecture Hall
    School of Chemistry, University of St. Andrews, St. Andrews, KY169ST, UK

    Abstract

    The development of sustainable methods for the closed-loop production and recycling of plastics is an important challenge of current times. Reactions based on catalytic (de)hydrogenation are atom-economic, and sustainable routes for organic transformations.1 Using the following examples, this lecture will discuss the application of homogeneous (de)hydrogenative catalysis for the synthesis and degradation of polymers to enable a circular economy: (a) synthesis of polyamides/nylons from the ruthenium catalysed dehydrogenative coupling of diamines and diols and its reverse reaction i.e. hydrogenative depolymerisation of nylons,2 (b) synthesis of polyureas from the ruthenium/manganese catalysed dehydrogenative coupling of diamines3,4 and methanol, and its reverse reaction, i.e. hydrogenative depolymerisation of polyureas (Figure 1B)5, (c) Synthesis of polyethyleneimines from manganese catalysed coupling of ethylene glycol and ethylenediamine or the self-coupling of ethanolamine,6 and (d) Synthesis of polyureas and polyurethanes from the dehydrogenative coupling of diformamides and diamines/diols and its reverse reaction i.e. hydrogenative depolymerisation of polyureas and polyurethanes to diformamides and diamines/diols.7 Some applications of some of the polymers made using dehydrogenative processes in the field of batteries will also be discussed.8
  • seminar
    Date:
    28 May
    2023
    Sunday
    Hours:
    16:00
    -
    17:00

    Magnetic Resonance Seminar: "Quantum sensing of out-of-equilibrium systems with magnetic resonance”

    Location: Perlman Chemical Sciences Building
    participants: Dr. Gonzalo A. Alvarez
    Centro Atómico Bariloche, Instituto Balseiro & Instituto de Nanociencia y Nanotecnologia

    Abstract

    Reliable processing of quantum information is crucial for quantum technologies development. Characterizing the ubiquitous out-of-equilibrium quantum systems [1-3] is essential for designing optimal control and quantum sensing strategies. However, this task is highly challenging due to the complex high-order correlations and non-stationary nature. In this talk, I will present methods to characterize the decoherence of out-of-equilibrium quantum systems [1,4-6]. Using quantum simulations with Solid-State Nuclear Magnetic Resonance, we quantify "out-of-time order correlations" (OTOCs [2-3]) to define a critical threshold in disturbances to achieve reliable control of large quantum systems [1,4-5]. Furthermore, we develop a framework for quantum sensing the dynamics of out-of-equilibrium systems [6]. The sensor manifests spectral and non-Markovian properties, providing a quantum technology to probe time-correlation properties and mitigate the decoherence effects of non-stationary environments. [1] G. A. Alvarez, D. Suter, R. Kaiser. Science 349, 846 (2015). [2] R.J. Lewis-Swan, A. Safavi-Naini, A.M. Kaufman, A.M. Rey. Nat. Rev. Phys. 1, 627 (2019). [3] B. Swingle. Nat. Phys. 14, 988 (2018). [4] F.D. Dominguez, M.C. Rodriguez, R. Kaiser, D. Suter, G.A. Alvarez. Phys. Rev. A 104, 012402 (2021). [5] F.D. Dominguez, G.A. Alvarez. Phys. Rev. A 104, 062406 (2021). [6] M. Kuffer, A. Zwick, G.A. Alvarez. PRX Quantum 3, 020321 (2022).
  • seminar
    Date:
    28 May
    2023
    Sunday
    Hours:
    11:00
    -
    12:00

    Studying the role of fluids in the mantle through natural samples and experiments

    Location: Sussman Family Building for Environmental Sciences
    participants: Ronit Kesel
    Institute of Earth Sciences, The Hebrew University of Jerusalem

    Abstract

    Mantle fluids are the primary carriers of key volatile elements that make the Earth’s long-term planetary habitability possible. The interaction of such volatile-rich fluids with the mantle rocks, especially the sub-cratonic lithospheric mantle leads to alteration of the mantle as well as its melting. High-density fluids encased inside diamonds are the best natural representation of mantle fluid compositions, suggesting their compositions are saline, silicic or carbonatitic. However, the origin and role in the mantle as well as their role in altering the mantle are still unclear. In my research, we approach these questions by experimentally simulating the interaction of volatile-rich fluids with mantle rocks at known pressure and temperature relevant to the mantle. Examining different mixtures of volatiles (H2O and CO2) and mantle rocks (peridotite and eclogite), we attempt to understand the origin of each type of fluid found in diamonds as well as study the effect of such interaction on the mantle chemistry and mineralogy. Compiling many experimental studies reveals that fluids ranging from silicic to low-Mg carbonatitic are formed in systems of eclogite+H2O+CO2, the more CO2 in the system, the more carbonatitic the fluid is. Fluids ranging from low-Mg carbonatitic to high-Mg carbonatitic in nature are the results of the formation of fluids in the peridotite-H2O-CO2 system. The more CO2 in the system, the more high-Mg carbonatitic the fluid composition is. These results suggest that the various fluids found in the mantle result from changes in the bulk composition of the mantle rocks. The mantle rocks are significantly affected during percolation of such fluids through them. For example, experimentally interacting silicic fluid with peridotite demonstrated the formation of various metasomatic peridotites as a function of pressure and temperature, composing of amphibole and mica. The mineral assemblages, chemistry, and P-T conditions in the experiments are similar to those found in metasomatic xenoliths from Kimberly, South Africa, and surrounding localities.
  • seminar
    Date:
    23 May
    2023
    Tuesday
    Hours:
    14:00
    -
    15:00

    Advances of Liquid Biopsy Diagnostics and Structural Models in the Development of Data-Driven AI in Future Hospitals

    Location: Gerhard M.J. Schmidt Lecture Hall
    participants: Dr. Milana Frenkel-Morgenstern
    Azrieli Faculty of Medicine Bar-Ilan University
  • seminar
    Date:
    21 May
    2023
    Sunday
    Hours:
    11:00
    -
    12:00

    “ Programmatic and Deep Learning Analysis Pipelines for 4D-STEM Materials Science Experiments”

    Location: Gerhard M.J. Schmidt Lecture Hall
    participants: Dr. Colin Ophus
    Lawrence Berkeley National Laboratory, Berkeley

    Abstract

    Scanning transmission electron microscopy (STEM) is one of the most popular materials science methods to characterize the structure and chemistry of nanoscale samples, owing to its high resolution and many flexible operating modes. In a conventional STEM experiment, we focus the electron beam down to a probe from nanometer to sub-angstrom scale, and scan it over the sample surface while recording diffracted signals which are transmitted through the specimen. STEM can also record analytic signals such as x-rays generated by the electron beam to measure composition, or energy loss of the transmitted electrons to probe the electronic structure of samples. Conventional STEM imaging detectors experiments produce only a few intensity values at each probe position, but modern high-speed detectors allow us to measure a full 2D diffraction pattern, over a grid of 2D probe positions, forming a four dimensional (4D)-STEM dataset. These 4D-STEM datasets record information about the local phase, orientation, deformation, and other parameters, for both crystalline and amorphous materials. 4D-STEM datasets can contain millions of images and therefore require highly automated and robust software codes to extract the target properties. In this talk, I will introduce our open source py4DSTEM analysis toolkit, and show how we use these codes to perform data-intensive studies of material properties over functional length scales. I will also demonstrate some applications of modern machine learning tools, to perform measurements on electron diffraction patterns where property signals have been scrambled by multiple scattering of the electron beam.
  • seminar
    Date:
    21 May
    2023
    Sunday
    Hours:
    11:00
    -
    12:00

    Determining past lake temperatures in saline lake systems using fluid inclusions: an example from the Dead Sea

    Location: Sussman Family Building for Environmental Sciences
    participants: Niels Brall
    The Hebrew University of Jerusalem

    Abstract

    In recent decades, various temperature proxies have been developed and further established in the scientific community, at both low and high accuracy, however, not every method can be applied without restriction to all minerals or rocks. Evaporitic rocks, for example, are abundant chemical sediments at the Earth's surface that are deposited from supersaturated brines in marine, terrestrial, and lacustrine environments. Halite is the most abundant rock-forming mineral in this group, which during crystal formation entraps tiny water droplets (fluid inclusions, FIs) that store the chemical composition of the parent brine at a specific pressure-temperature dependent density. Such FIs are therefore excellent records of the original physicochemical conditions of the source brine. Brillouin spectroscopy (BS) is a novel laser-based technique that uses density fluctuations in FIs to directly measure entrapment temperatures and thus the initial brine temperature during crystal growth. In this seminar, the BS method will be introduced and two application cases will be presented using salt layers from the Dead Sea which were deposited during two interglacial periods. In addition to the basic principles, both the recommended sampling strategy and pitfalls along with associated limitations will be presented. The conclusion will be that the salt layers commonly deposited in the Dead Sea basin consist of two types that formed preferentially in summer (coarse-grained crystals) and winter (fine-grained crystals), which is mainly controlled by the degree of salt saturation of the lake water. Furthermore, it will be shown how (1) lake bottom temperatures have fluctuated seasonally (summer/winter), and that (2) paleo temperature trends can be reconstructed for an entire halite layer that was deposited during holomictic periods in the Dead Sea basin. This method is particularly promising for evaporites that formed near the surface if the material has not been affected by external processes such as tectonic burial/uplift, erosion, or mineral replacement.
  • seminar
    Date:
    18 May
    2023
    Thursday
    Hours:
    09:30
    -
    10:30

    Non-invasive Methods for Extracting Microstructural Information from Human Tissues: Implementation in a Clinical MRI Scanner

    Location: Gerhard M.J. Schmidt Lecture Hall
    participants: Ana Naamat
    Medical Physics Department, Bariloche Atomic Center

    Abstract

    Extracting quantitative information about tissue microstructure using non-invasive methods is an exceptional challenge in understanding disease mechanisms and enabling early diagnosis of pathologies. Magnetic Resonance Imaging (MRI) is a promising and widely used technique to achieve this goal, but it still provides low resolution to reveal details of the microstructure. Recently, we have developed methods to produce images with quantitative information about the microstructure based on selective probing of spin dephasing induced by molecular diffusion restriction in cavities of the tissue microstructure [1-3]. The feasibility of the theoretical method has been demonstrated so far by first-principles experiments and simulations on typical size distributions of white matter in the mouse brain [3]. As a next step towards practical implementation, we have implemented this method in clinical scanners [4]. In this work, I present the challenges and preliminary results of this implementation in both phantoms and human volunteers. These results open up a new avenue for MRI to advance in extracting quantitative, and fast microstructural information from images. [1] A. Zwick, D. Sueter, G. Kurizki, G. A. Álvarez, Phys. Rev. Applied 14, 024088, (2020). [2] M. Capiglioni, A. Zwick, P. Jiménez, G. A. Álvarez. Proc. Intl. Soc. Mag. Reson. Med. 29, 2036 (2021) [3] M. Capiglioni, A. Zwick, P. Jiménez and G. A. Álvarez, Phys. Rev. Applied 15, 014045 (2021). [4] E. Saidman, A. Zwick, S. Tambalo, T. Feiweier, J. Jovicich, G. A. Álvarez. Proc. Intl. Soc. Mag. Reson. Med. (2023)
  • seminar
    Date:
    15 May
    2023
    Monday
    Hours:
    11:00
    -
    12:00

    KENDREW LECTURE: Computational Structural Biology in the Era of Deep Learning

    Location: Gerhard M.J. Schmidt Lecture Hall
    participants: Prof. John Moult
    Institute of Bioscience and Biotechnology Research Department of Cell Biology and Molecular Genetics University of Maryland
  • seminar
    Date:
    14 May
    2023
    Sunday
    Hours:
    11:00
    -
    12:00

    Projecting the impacts of climate change on human society

    Location: Sussman Family Building for Environmental Sciences
    participants: Ram Fishman
    Tel Aviv University