• 1 Nov 2021 Journal Article Combustion and Flame

    Flame stabilization and local combustion modes in a cavity-based scramjet using different fuel injection schemes

    This paper investigates the impact of fuel distribution on flame stabilization and local combustion modes in a cavity-based scramjet. Two injection schemes with a global equivalence ratio of 0.4 are comparatively studied. Ethylene is injected only from upstream of the cavity in the first case, whereas in the second case 75% of the fuel is injected from upstream of the show more
  • 8 Sep 2021 Journal Article Journal of the American Chemical Society

    A Di-Copper-Peptoid in a Noninnocent Borate Buffer as a Fast Electrocatalyst for Homogeneous Water Oxidation with Low Overpotential

    Water electrolysis is a promising approach toward low-cost renewable fuels; however, the high overpotential and slow kinetics limit its applicability. Studies suggest that either dinuclear copper (Cu) centers or the use of borate buffer can lead to efficient catalysis. We previously demonstrated the ability of peptoids-N-substituted glycine oligomers-to stabilize show more
  • 3 Sep 2021 Journal Article

    Spatial Distribution of Solar Cell Parameters in Multigrain Halide-Perovskite Films: A Device Model Perspective

    Sapir Bitton, Qingzhi An, Yana Vaynzof, Nir Tessler
    The polycrystalline nature of perovskite thin films suggests that the nonradiative recombination losses may be grain size dependent. We use measured grain size distributions of methylammonium lead triiodide layers to describe the macroscopic solar cell as composed of multiple single grain size cells operating in parallel. Using a model, we show that the grain size show more
  • 1 Sep 2021 Journal Article Electrochimica Acta

    Single Flow Multiphase Flow Batteries: Theory

    Rona Ronen, Amir D Gat, Martin Z Bazant, Matthew E Suss
    Redox flow batteries are an emerging technology for stationary, grid-scale energy storage. Membraneless batteries in particular are explored as a means to reduce battery cost and complexity. Here, a mathematical model is presented for a membraneless electrochemical cell employing a single laminar flow between electrodes, consisting of a continuous, reactant-poor aqueous show more
  • 30 Aug 2021 Journal Article Nature Plants

    Cryo-EM photosystem I structure reveals adaptation mechanisms to extreme high light in Chlorella ohadii

    Ido Caspy, Ehud Neumann, Maria Fadeeva, Varda Liveanu, Anton Savitsky, Anna Frank, Yael Levi-Kalisman, Yoel Shkolnisky, Omer Murik, Haim Treves, Volker Hartmann, Marc M Nowaczyk, Wolfgang Schuhmann, Matthias Rögner, Itamar Willner, Aaron Kaplan, Gadi Schuster, Nathan Nelson, Wolfgang Lubitz, Rachel Nechushtai
    Photosynthesis in deserts is challenging since it requires fast adaptation to rapid night-to-day changes, that is, from dawn’s low light (LL) to extreme high light (HL) intensities during the daytime. To understand these adaptation mechanisms, we purified photosystem I (PSI) from Chlorella ohadii, a green alga that was isolated from a desert soil crust, and show more
  • 26 Aug 2021 Journal Article Journal of Power Sources Advances

    A surprising relation between operating temperature and stability of anion exchange membrane fuel cells

    Anion-exchange membrane fuel cells (AEMFCs) show substantially enhanced (initial) performance and efficiency with the increase of operational temperature (where typical values are below 80 °C). This is directly due to the increase in reaction and mass transfer rates with temperature. Common sense suggests however that the increase of ionomeric material chemical show more
  • 24 Aug 2021 Journal Article Chemistry of Materials

    Silver Tipping of CdSe@CdS Nanorods: How To Avoid Cation Exchange

    Cadmium chalcogenides–metal hybrid nanostructures play an important role in a wide range of applications and are key components in photocatalysis. Hence, great efforts have been devoted to the exploration of a variety of metal components, each offering different functionalities. Silver is a vital catalyst used in the production of major industrial chemicals, found in show more
  • 24 Aug 2021 Journal Article Applied Catalysis B: Environmental

    Multi-scale study on bifunctional Co/Fe–N–C cathode catalyst layers with high active site density for the oxygen reduction reaction

    Weikang Zhu, Yabiao Pei, John C Douglin, Junfeng Zhang, Haoyang Zhao, Jiandang Xue, Qingfa Wang, Ran Li, Yanzhou Qin, Yan Yin, Dario R Dekel, Michael D Guiver
    Recently, much work has been devoted to designing catalysts with high porosity and efficient active sites. Although very promising results are achieved using Co/Fe–N–C catalysts based on rotating disk electrode (RDE) tests, actual fuel cell performance is below expectations, probably due to insufficient understanding of the catalyst layer (CL). Therefore, catalyst design show more
  • 24 Aug 2021 Journal Article

    Bifunctional Oxygen Electrocatalysis on Mixed Metal Phthalocyanine-Modified Carbon Nanotubes Prepared via Pyrolysis

    Yogesh Kumar, Elo Kibena-Põldsepp, Jekaterina Kozlova, Mihkel Rähn, Alexey Treshchalov, Arvo Kikas, Vambola Kisand, Jaan Aruväli, Aile Tamm, John C Douglin, Scott J Folkman, Ilario Gelmetti, Felipe A Garcés-Pineda, José Ramón Galán-Mascarós, Dario R Dekel, Kaido Tammeveski
    Non-precious-metal catalysts are promising alternatives for Pt-based cathode materials in low-temperature fuel cells, which is of great environmental importance. Here, we have investigated the bifunctional electrocatalytic activity toward the oxygen reduction reaction (ORR) and the oxygen evolution reaction (OER) of mixed metal (FeNi; FeMn; FeCo) phthalocyanine-modified show more
  • 23 Aug 2021 Journal Article Angewandte Chemie

    Photoinduced Self-Assembly of Carbon Nitride Quantum Dots

    The study of nanocrystal self-assembly into superlattices or superstructures is of great significance in nanoscience. Carbon nitride quantum dots (CNQDs), being a promising new group of nanomaterials, however, have hardly been explored in their self-organizing behavior. Here we report of a unique irradiation-triggered self-assembly and recrystallization phenomenon of show more
  • 20 Aug 2021 Journal Article iScience

    Hydrogen evolution catalysis by terminal molybdenum-oxo complexes

    Stable complexes with terminal triply bound metal-oxygen bonds are usually not considered as valuable catalysts for the hydrogen evolution reaction (HER). We now report the preparation of three conceptually different (oxo)molybdenum(V) corroles for testing if proton-assisted 2-electron reduction will lead to hyper-reactive molybdenum(III) capable of converting protons show more
  • 12 Aug 2021 Journal Article Advanced Materials

    A Protein-Based Free-Standing Proton-Conducting Transparent Elastomer for Large-Scale Sensing Applications

    A most important endeavor in modern materials' research is the current shift toward green environmental and sustainable materials. Natural resources are one of the attractive building blocks for making environmentally friendly materials. In most cases, however, the performance of nature-derived materials is inferior to the performance of carefully designed synthetic show more
  • 12 Aug 2021 Journal Article Analytical Chemistry

    Utilization of FAD-Glucose Dehydrogenase from T. emersonii for Amperometric Biosensing and Biofuel Cell Devices

    Flavin-dependent glucose dehydrogenases (FAD-GDH) are oxygen-independent enzymes with high potential to be used as biocatalysts in glucose biosensing applications. Here, we present the construction of an amperometric biosensor and a biofuel cell device, which are based on a thermophilic variant of the enzyme originated from Talaromyces emersonii. The enzyme overexpression show more
  • 11 Aug 2021 Journal Article ACS Applied Materials & Interfaces

    Kinetic Resolution of Racemic Mixtures via Enantioselective Photocatalysis

    Despite the increasing demand for enantiopure drugs in the pharmaceutical industry, currently available chiral separation technologies are still lagging behind, whether due to throughput or to operability considerations. This paper presents a new kinetic resolution method, based on the specific adsorption of a target enantiomer onto a molecularly imprinted surface of show more
  • 3 Aug 2021 Journal Article Nature Communications

    High-Performance Photonic Transformers for DC Voltage Conversion

    Bo Zhao, Sid Assawaworrarit, Parthiban Santhanam, Meir Orenstein, Shanhui Fan
    Direct current (DC) converters play an essential role in electronic circuits. Conventional high-efficiency DC voltage converters, especially step-up type, rely on switching operation, where energy is periodically stored within and released from inductors and/or capacitors connected in a variety of circuit topologies. Since these energy storage components, especially show more
  • 3 Aug 2021 Journal Article Annual Review of Microbiology

    Microbial Rhodopsins: The Last Two Decades

    Andrey Rozenberg, Keiichi Inoue, Hideki Kandori, Oded Beja
    Microbial rhodopsins are diverse photoreceptive proteins containing a retinal chromophore and are found in all domains of cellular life and are even encoded in genomes of viruses. These rhodopsins make up two families: type 1 rhodopsins and the recently discovered heliorhodopsins. These families have seven transmembrane helices with similar structures but opposing show more
  • 2 Aug 2021 Journal Article ChemSusChem

    AZ31 Magnesium Alloy foils as thin Anodes for Rechargeable Magnesium Batteries

    Ananya Maddegalla, Ayan Mukherjee, J Alberto Blázquez, Eneko Azaceta, Olatz Leonet, Aroa R Mainar, Aleksey Kovalevsky, Daniel Sharon, Jean-Frédéric Martin, Dane Sotta, Yair Ein-Eli, Doron Aurbach, Malachi Noked
    In recent decades rechargeable Mg batteries (RMB) technologies have attracted much attention because the use of thin Mg foils anodes may enable to develop high energy density batteries. One of the most critical challenges for devolving RMB is finding suitable electrolyte solutions that enable efficient and reversible Mg cells operation. Most RMB studies concentrate show more
  • 2 Aug 2021 Journal Article Physics of Fluids

    Flow field characteristics of a confined, underexpanded transient round jet

    The flow field of an impulsively started round, confined nitrogen jet was investigated using combined high speed schlieren imaging and particle velocimetry (PIV) measurements. PIV measurements were carried out at five different, normalized times (55 ≤t≤ 392) relative to jet intrusion into a constant volume chamber. Between 100 show more
  • 1 Aug 2021 Journal Article Energy and Environmental Science

    Wasted photons: photogeneration yield and charge carrier collection efficiency of hematite photoanodes for photoelectrochemical water splitting

    Hematite (α-Fe2O3) is a leading photoanode candidate for photoelectrochemical water splitting. Despite extensive research efforts, the champion hematite photoanodes reported to date have achieved less than half of the maximal photocurrent predicted by its bandgap energy. Here we show that this underachievement arises, to a large extent, because of show more
  • 1 Aug 2021 Journal Article Organic and Hybrid Sensors and Bioelectronics XIV

    Bioderived electronics: utilizing proteins for making large scale assemblies exhibiting superior electronic and optoelectronic properties

    Nature uses proteins for a variety of functions, and among all others, their ability to form high-hierarchical structures as well as to mediate charges. We are inspired by these functions of proteins in nature and utilize proteins for the formation of large-scale conductive materials. We report here on a new family of conductive biopolymers using only sustainable and show more
  • 29 Jul 2021 Conference Paper 2021 IEEE Madrid PowerTech

    Assessing Energy Generation and Consumption Patterns in Times of Crisis: COVID-19 as a Case Study

    The COVID-19 pandemic and the preventive measures that followed it have significantly impacted generation and consumption patterns in power systems across the globe, calling for new tools to efficiently evaluate generation and load profiles. In this work, we propose one possible tool, which we name the smoothness index, that evaluates a profile based on both its load show more
  • 29 Jul 2021 Conference Paper 2021 IEEE Madrid PowerTech

    A Comparative Study on Graph-based Ranking Algorithms for Consumer-oriented Demand Side Management

    Abiodun E Onile, Juri Belikov, Eduard Petlenkov, Yoash Levron
    In the recent years, the impact of urban climate change and ever-expanding needs for electricity energy calls for urgent attention. Generally, electricity can be conserved by implementing efficiency models that handle effective utilization. To set and monitor energy conservation goals at consumer end, this study presents an innovative ranking approach as Demand Side show more
  • 29 Jul 2021 Conference Paper 2021 IEEE Madrid PowerTech

    Construction of Nonlinear Feedback Strategies for Energy Storage Systems: a Stochastic Dynamic Programming Approach

    Nilanjan Roy Chowdhury, Dmitry Baimel, Juri Belikov, Yoash Levron
    It is currently observed that rapid changes in generation and consumption can significantly impact the stability of a power system. In this light, this paper proposes a nonlinear feedback strategy for energy storage systems which operates under uncertainty conditions, and does not require statistical representations of future signals. We employ stochastic dynamic show more
  • 24 Jul 2021 Preprint arXiv

    Thermodynamics of light management in near-field thermophotovoltaics

    Georgia T Papadakis, Meir Orenstein, Eli Yablonovitch, Shanhui Fan
    We evaluate near-field thermophotovoltaic (TPV) energy conversion systems focusing in particular on their open-circuit voltage (Voc). Unlike previous analyses based largely on numerical simulations with fluctuational electrodynamics, here, we develop an analytic model that captures the physics of near-field TPV systems and can predict their performance metrics. Using show more
  • 22 Jul 2021 Journal Article ACS Applied Materials & Interfaces

    Electrospun Ion-Conducting Composite Membrane with Buckling-Induced Anisotropic Through-Plane Conductivity

    Fuel cell (FC) is an attractive green alternative for today's fuel combustion systems. In common FCs, a polymer electrolyte membrane selectively conducts protons but blocks the passage of electrons and fuel. Nafion, the current benchmark membrane material, has a superior conductivity owing to unique morphology comprising randomly oriented elongated ionic nanochannels show more
  • 21 Jul 2021 Journal Article Chemical Communications

    Combining polarized low-frequency Raman with XRD to identify directional structural motifs in a pyrolysis precursor

    Tal Ben Uliel, Eliyahu M Farber, Hagit Aviv, Wowa Stroek, Marilena Ferbinteanu, Yaakov R Tischler, David Eisenberg
    Long–range structures and dynamics are central to coordination chemistry, yet are hard to identify experimentally. By combining polarized low-frequency Raman spectroscopy with single crystal XRD to study barium nitrilotriacetate, a metal–organic coordination polymer and a useful pyrolysis precursor, we could assign Raman peaks experimentally to layer shear motions and show more
  • 19 Jul 2021 Journal Article Advanced Energy Materials

    Fast Charging of Lithium-Ion Batteries: A Review of Materials Aspects

    Manuel Weiss, Raffael Ruess, Johannes Kasnatscheew, Yehonatan Levartovsky, Natasha Ronith Levy, Philip Minnmann, Lukas Stolz, Thomas Waldmann, Margret Wohlfahrt-Mehrens, Doron Aurbach, Martin Winter, Yair Ein-Eli, Jürgen Janek
    Fast charging is considered to be a key requirement for widespread economic success of electric vehicles. Current lithium-ion batteries (LIBs) offer high energy density enabling sufficient driving range, but take considerably longer to recharge than traditional vehicles. Multiple properties of the applied anode, cathode, and electrolyte materials influence the fast-charging show more
  • 17 Jul 2021 Journal Article Biotechnology for Biofuels

    Cellulosic biofuel production using emulsified simultaneous saccharification and fermentation (eSSF) with conventional and thermotolerant yeasts

    Shannon M Hoffman, Maria Alvarez, Gilad Alfassi, Dmitry M Rein, Sergio Garcia-Echauri, Yachin Cohen, José L Avalos
    Future expansion of corn-derived ethanol raises concerns of sustainability and competition with the food industry. Therefore, cellulosic biofuels derived from agricultural waste and dedicated energy crops are necessary. To date, slow and incomplete saccharification as well as high enzyme costs have hindered the economic viability of cellulosic biofuels, and while show more
  • 15 Jul 2021 Journal Article Advanced Energy Materials

    Molecular Engineering Approaches to Fabricate Artificial Solid-Electrolyte Interphases on Anodes for Li-Ion Batteries: A Critical Review

    Roman G Fedorov, Sebastian Maletti, Christian Heubner, Alexander Michaelis, Yair Ein-Eli
    An intrinsic challenge of Li-ion batteries is the instability of electrolytes against anode materials. For anodes with a favorably low operating potential, a solid-electrolyte interphase (SEI) formed during initial cycles provides stability, traded off for capacity consumption. The SEI is mainly determined by the anode material, electrolyte composition, and formation show more
  • 15 Jul 2021 Journal Article Water Research

    Flow-electrode capacitive deionization: A review and new perspectives

    Fan Yang, Yunfei He, Leon Rosentsvit, Matthew E Suss, Xiaori Zhang, Tie Gao, Peng Liang
    Flow-electrode capacitive deionization (FCDI), as a novel electro-driven desalination technology, has attracted growing exploration towards brackish water treatment, hypersaline water treatment, and selective resource recovery in recent years. As a flow-electrode-based electrochemical technology, FCDI has similarities with several other electrochemical technologies such show more
  • 13 Jul 2021 Journal Article Chemical Engineering Journal Advances

    A high-temperature anion-exchange membrane fuel cell with a critical raw material-free cathode

    John C Douglin, Ramesh Kumar Singh, Saja Haj-Bsoul, Songlin Li, Jasper Biemolt, Ning Yan, John R Varcoe, Gadi Rothenberg, Dario R Dekel
    We present a first high-temperature anion-exchange membrane fuel cell (HT-AEMFC, operating at 105 °C) based on a critical raw material (CRM)-free cathode catalyst; at the same temperature, the anion-exchange membrane (AEM) has a high ex-situ hydroxide conductivity value of 201 mS cm−1. Our HT-AEMFC, containing a highly active nitrogen-doped carbon (N-doped-C) show more
  • 12 Jul 2021 Journal Article Sustainable Energy & Fuels

    Cellulose to Electricity Conversion by Bias-Free Biofuel Cell

    The conversion of biomass and other cellulose-based materials to clean energy has high promise for a sustainable world. Herein we present a green methodology to convert cellulose directly into electrical power output by utilizing cellulase complex and an enzymatic biofuel cell. An integrated FAD-dependent glucose dehydrogenase (FAD-GDH) based anode and a bilirubin show more
  • 9 Jul 2021 Journal Article Molecules

    Enhanced Electrochemical Performance of Supercapacitors via Atomic Layer Deposition of ZnO on the Activated Carbon Electrode Material

    Chongrui Wu, Fuming Zhang, Xiangshang Xiao, Junyan Chen, Junqi Sun, Dayakar Gandla, Yair Ein-Eli, Daniel Qi Tan
    Fabricating electrical double-layer capacitors (EDLCs) with high energy density for various applications has been of great interest in recent years. However, activated carbon (AC) electrodes are restricted to a lower operating voltage because they suffer from instability above a threshold potential window. Thus, they are limited in their energy storage. The deposition show more
  • 1 Jul 2021 Journal Article Chemical Science

    Long-range light-modulated charge transport across the molecular heterostructure doped protein biopolymers

    Somen Mondal, Nandan Ghorai, Soumyadip Bhunia, Hirendra N Ghosh, Nadav Amdursky
    Electron transfer (ET) across proteins is ubiquitous in nature, such as the notable photosynthesis example, where light-induced charge separation takes place within the reaction center, followed by sequential ET via intramolecular cofactors within the protein. Here, we introduce carbon dots (C-Dots), which are slowly gaining momentum in being game changers for next show more
  • 25 Jun 2021 Journal Article Macromolecular Rapid Communications

    Ligand Valency Effects on the Alkaline Stability of Metallopolymer Anion-Exchange Membranes

    Long-term stability is a key requirement for anion-exchange membranes (AEMs) for alkaline fuel cells and electrolyzers that is yet to be fulfilled. Different cationic chemistries are being exploited to reach such a goal, and metallopolymers present the unique advantage of chemical stability towards strong nucleophiles as compared to organic cations. Yet, the few show more
  • 24 Jun 2021 Journal Article Journal of Materials Chemistry A

    Functionalized gold-nanoparticles enhance photosystem II driven photocurrent in a hybrid nano-bio-photoelectrochemical cell

    The use of photosystem II (PSII) in hybrid bio-photoelectrochemical cells for conversion of solar energy to electrical current is hampered by PSII's narrow absorption cross-section and the generally poor electrical connection between isolated complex and different anode materials. Here, we merge isolated market-grade spinach PSII with 25 nm cystamine-2,6-dichlorobenzoquinone show more
  • 17 Jun 2021 Journal Article Journal of Power Sources

    Exploring the mechanical stability of manganese oxide as an electrocatalyst via in-situ surface stress and electrochemical quartz crystal microbalance studies

    Or Keisar, Yair Ein-Eli, Yair Cohen
    We report in this study on the combination of resonance frequency shift measurements with the use of Electrochemical Quartz Crystal Microbalance (EQCM), alongside in-situ electrochemical surface stress (ESS) analysis, which provides a comprehensive description of both the microscopic and macroscopic processes occurring on the surface of the oxygen reduction show more
  • 15 Jun 2021 Journal Article Building and Environment

    Thermal performance of sculptured tiles for building envelopes

    Since effective thermal insulation of buildings could significantly decrease energy consumption worldwide, this study examined the potential of concrete tiles with complex geometries at improving thermal performance in building envelopes. The study focused on air flow characteristics that occur near the external surface of the tile, and their influence on the rate of show more
  • 14 Jun 2021 Journal Article

    The effect of surface phase oxides on the properties of supported metals and catalysis

    Christine Khoury, Matthew M Montemore, Oz M Gazit
    Metal–support interactions have a strong and pivotal influence on catalyst properties. In many cases, these interactions can direct reaction activity, stability, and selectivity. Hence, controlling such interactions has high potential for enhancing catalytic performance. One approach to controlling metal–support interactions is to use a surface phase oxide, wherein a show more
  • 10 Jun 2021 Journal Article Frontiers for Young Minds

    Using Computers to Discover Materials That Generate Non-polluting Fuels

    Non-polluting fuels, such as hydrogen, are widely considered to be a promising way to decrease the environmental problems caused by the burning of fossil fuels. Finding materials that can help us to generate these “clean” fuels is a difficult and time-consuming process. Computer simulation technology is the most important tool in this area, because it helps scientists show more
  • 10 Jun 2021 Journal Article Journal of Physical Chemistry C

    Development of a Typical Distribution Function of Relaxation Times Model for Polymer Electrolyte Membrane Fuel Cells and Quantifying the Resistance to Proton Conduction within the Catalyst Layer

    In recent decades, polymer electrolyte membrane fuel cell (PEMFC) technologies have attracted research attention as promising candidates for next-generation energy conversion systems. This work deals with the effect of operating conditions and the construction of a typical model for PEMFCs, using electrochemical impedance spectroscopy (EIS) and distribution of relaxation show more
  • 3 Jun 2021 Journal Article Energy & Fuels

    Correlating Properties of the Mn2O3-Na2WO4/SiO2 Catalyst with Statistically Estimated Parameters for the Oxidative Coupling of Methane

    Baoting Huang, Naseem Hayek, Guanjie Sun, Sogol Mottaghi-Tabar, David S A Simakov, Oz M Gazit
    Identifying key catalyst parameters that govern catalytic performance is a main challenge for many reactions. The complex and convoluted behavior of the Mn2O3-Na2WO4/SiO2 catalyst for the oxidative coupling of methane (OCM) makes this task even more challenging. Herein, structure–function correlations are obtained show more
  • 1 Jun 2021 Journal Article Advanced Functional Materials

    Porphyrin Aerogel Catalysts for Oxygen Reduction Reaction in Anion‐Exchange Membrane Fuel Cells

    Noam Zion, John C Douglin, David A Cullen, Piotr Zelenay, Dario R Dekel, Lior Elbaz
    Platinum group metal (PGM)‐free catalysts for oxygen reduction reaction have shown high oxygen reduction reaction activity in alkaline media. In order to further increase the power density of anion‐exchange membrane fuel cells (AEMFCs), PGM‐free catalysts need to have a high site density to reach high current densities. Herein, synthesis, characterization, and utilization show more
  • 30 May 2021 Conference Paper 239th ECS Meeting With the 18th International Meeting on Chemical Sensors (IMCS)

    Continuum Approach for Studying Morphological Deformations of Multiple-Phase Organic Photovoltaic Cells

    Alon Z Shapira, Nir Gavish, Hannes Uecker, Arik Yochelis
    Optimizing the properties of the mosaic morphology of bulk heterojunction (BHJ) organic photovoltaics (OPV) is not only challenging technologically but also intriguing from the mechanistic point of view. Among the recent breakthroughs in studies of BHJ morphology, is the identification and utilization of a three-phase (donor/mixed/acceptor) BHJ, where the (intermediate) show more
  • 28 May 2021 Journal Article ACS Applied Nano Materials

    Effects of Microstructure and Neodymium Doping on Bi2Te3 Nanostructures: Implications for Thermoelectric Performance

    Gil Solomon, Erdong Song, Chhatrasal Gayner, Julio A Martinez, Yaron Amouyal
    We report on an intriguing aspect of the effects of microstructure and chemistry on thermoelectric (TE) transport properties of nanostructured Bi2Te3-based compounds that are associated with their topologically insulating (TI) nature. Nanograined n-type Bi2Te3 and Bi1.94Nd0.06Te3 samples were show more
  • 26 May 2021 Journal Article Soft Matter

    Enhanced ordering in length-polydisperse carbon nanotube solutions at high concentrations as revealed by small angle X-ray scattering

    Vida Jamali, Francesca Mirri, Evan G Biggers, Robert A Pinnick, Lucy Liberman, Yachin Cohen, Yeshayahu Talmon, Fred C MacKintosh, Paul van der Schoot, Matteo Pasquali
    Carbon nanotubes (CNTs) are stiff, all-carbon macromolecules with diameters as small as one nanometer and few microns long. Solutions of CNTs in chlorosulfonic acid (CSA) follow the phase behavior of rigid rod polymers interacting via a repulsive potential and display a liquid crystalline phase at sufficiently high concentration. Here, we show that small-angle X-ray show more
  • 21 May 2021 Journal Article Journal of Thermophysics and Heat Transfer

    Ultrasonic Temperature Compensating Method for Tracking Decomposition Front in Silica-Phenolic Thermal Protection Material

    Aleksander Zibitsker, Moshe Berreby, Dan Michaels, Ramin Shilav, Ilya Frisman
    This paper presents an ultrasonic method for tracking the decomposition front in ablating silica-phenolic thermal protection system material. The method exploits diffuse ultrasonic backscatter from the material microstructure to account for the temperature-dependent change of the speed of sound. The method is demonstrated in a series of ablation tests performed at a show more
  • 13 May 2021 Journal Article Small

    Template-Free Formation of Regular Macroporosity in Carbon Materials Made from a Folded Polymer Precursor

    Porous carbon materials attract great interest in a wide range of applications such as batteries, fuel cells, and membranes, due to their large surface area, structural and compositional tunability, and chemical stability. While micropores are typically obtained when preparing carbon materials by pyrolysis, the fabrication of mesoporous, and especially macroporous show more
  • 3 May 2021 Journal Article AIAA Journal

    Rotor Performance Enhancement Using Pulsed Plasma Actuation

    Single and multirotor drones are increasingly used for commercial and humanitarian applications, including product delivery [1], disaster relief [2], wildlife tracking [3], agriculture [4], andlab-on-a-drone functions [5]. Their main advantages include vertical takeoff and landing (VTOL) capability, hovering, and autonomous flight over difficult [6] and complex terrains show more
  • 2 May 2021 Journal Article Electric Power Systems Research

    New type of bridge fault current limiter with reduced power losses for transient stability improvement of DFIG wind farm

    Dmitry Baimel, Nilanjan Roy Chowdhury, Juri Belikov, Yoash Levron
    The paper presents a new active diode bridge fault current limiter (FCL) topology, and compares it to the classic diode bridge, Series Dynamic Breaking Resistor (SDBR), and active diode bridge FCL circuits. The comparison is done using a benchmark system that includes a 9 MW wind turbine with a doubly fed induction generator (DFIG), two 50 MW synchronous generators, and show more
  • 28 Apr 2021 Preprint arXiv

    Evidence for ultra long range energy transfer in organic photovoltaic donor-acceptor three dimensional films

    We report an ultra long range energy transfer in a layered donor:spacer:acceptor structures, which consist of the typical organic photovoltaic material system of P3HT as the donor and PCBM as the acceptor. By varying the thicknesses of spacer and acceptor layers we show that the energy transfer is to the full volume of the acceptor and not just to its nearest interface show more
  • 19 Apr 2021 Journal Article Nature Materials

    Extraction of mobile charge carrier photogeneration yield spectrum of ultrathin-film metal oxide photoanodes for solar water splitting

    Daniel A Grave, David S Ellis, Yifat Piekner, Moritz Kölbach, Hen Dotan, Asaf Kay, Patrick Schnell, Roel van de Krol, Fatwa F Abdi, Dennis Friedrich, Avner Rothschild
    Light absorption in strongly correlated electron materials can excite electrons and holes into a variety of different states. Some of these excitations yield mobile charge carriers, whereas others result in localized states that cannot contribute to photocurrent. The photogeneration yield spectrum, ξ(λ), represents the wavelength-dependent ratio between the contributing show more
  • 19 Apr 2021 Journal Article Journal of Power Sources

    A binary carbon-free aluminum anode for lithium-ion batteries

    Modern applications require high energy density lithium-ion batteries (LIBs), inciting the search for high capacity anode materials. Recently, Aluminum (Al) anodes have reemerged as Li-alloyed anode material, but so far have not presented sufficient performance with commercially acceptable mass loadings. Interestingly, the active material intrinsic conductivity is not show more
  • 16 Apr 2021 Journal Article Energy Conversion and Management

    Performance and pollutant emission of the reforming-controlled compression ignition engine – Experimental study

    The reforming-controlled compression ignition (RefCCI) is an innovative concept integrating the benefits of the low-temperature combustion engine and the High-Pressure Thermochemical Recuperation. This combination enables achieving high thermal efficiency in a wide operating range while mitigating pollutant emissions. This work reports for the first time on results of show more
  • 15 Apr 2021 Journal Article ACS Applied Materials & Interfaces

    Doped Organic Hole Extraction Layers in Efficient PbS and AgBiS2 Quantum Dot Solar Cells

    David Becker-Koch, Miguel Albaladejo-Siguan, Yvonne J Hofstetter, Olga Solomeshch, Darius Pohl, Bernd Rellinghaus, Nir Tessler, Yana Vaynzof
    The efficiency of PbS quantum dot (QD) solar cells has significantly increased in recent years, strengthening their potential for industrial applications. The vast majority of state-of-the-art devices utilize 1,2-ethanedithiol (EDT)-coated PbS QD hole extraction layers, which lead to high initial performance, but result in poor device stability. While excellent performance show more
  • 12 Apr 2021 Journal Article Applied Physics Letters

    Intrinsic-polarization origin of photoconductivity in MAPbI3 thin films

    Hybrid halide perovskites (HHPs) exhibit exceptional photoelectric properties, facilitating highly efficient modern solar cells and photoconductive technologies. Both ion migration and intrinsic spontaneous polarization have been proposed as the main source of enhanced photoelectric activity, but the exact origin of the advantageous properties has remained elusive. Here show more
  • 6 Apr 2021 Technical Paper SAE Technical Paper Series

    Power and Efficiency Characteristics of a Hybrid Electrochemical-ICE Cycle

    Power and efficiency characteristics of a hybrid cycle combining an electrochemical device (Fuel-Cell) and an internal combustion engine (ICE) were analyzed using the low-dissipation model. The low-dissipation model links energy dissipation with the energy transfer rate through the cycle. In the considered cycle, the electrochemical device transforms chemical potential show more
  • 6 Apr 2021 Journal Article Frontiers in Energy Research

    Synergy of Oxygen Plasma and Al2O3 Atomic Layer Deposition on Improved Electrochemical Stability of Activated Carbon-Based Supercapacitor

    Fuming Zhang, Guanghui Song, Dayakar Gandla, Yair Ein-Eli, Daniel Qi Tan
    As a conventional electrode material of electric double-layer capacitors (EDLC), activated carbon (AC) still faces challenges to exhibit high capacitance. To address this problem, herein, we introduce a combined method of oxygen plasma and Al2O3 tomic layer deposition (ALD) on AC electrodes to reduce the impedance and improve the cycle stability show more
  • 5 Apr 2021 Journal Article IEEE Transactions on Power Delivery

    Minimal Output Impedance Required for Stability of Grid-Supporting Inverters

    In the field of power system dynamics, a main challenge is to properly tune the inverter control parameters, where one important parameter is the inverter's output impedance, physical or virtual. In this work, we provide a proof showing that a minimal output impedance must be used in order to keep the system stable. Although this result is well-known among practicing show more
  • 1 Apr 2021 Journal Article ACS Applied Energy Materials

    Effect of the Synthetic Method on the Properties of Ni-Based Hydrogen Oxidation Catalysts

    Elena S Davydova, Maidhily Manikandan, Dario R Dekel, Svein Sunde
    The latest progress in alkaline anion-exchange membranes has led to the expectation that less costly catalysts than those of the platinum-group metals may be used in anion-exchange membrane fuel cell devices. In this work, we compare structural properties and the catalytic activity for the hydrogen-oxidation reaction (HOR) for carbon-supported nanoparticles of Ni show more
  • 24 Mar 2021 Journal Article Physical Chemistry of Semiconductor Materials and Interfaces XX

    Small grains as recombination hot spots in perovskite solar cells

    Qingzhi An, Fabian Paulus, David Becker-Koch, Changsoon Cho, Qing Sun, Andreas Weu, Sapir Bitton, Nir Tessler, Yana Vaynzof
    Non-radiative recombination in the perovskite bulk and at its interfaces prohibits the photovoltaic performance from reaching the Shockley-Queisser limit. While interfacial recombination has been widely discussed and demonstrated, bulk recombination and especially the influence of grain boundaries remain under debate. Most studies explore the role of grain boundaries show more
  • 17 Mar 2021 Journal Article Applied Materials Today

    Revealing and excluding the root cause of the electronic conductivity in Mg-ion MgSc2Se4 solid electrolyte

    MgSc2Se4 is a promising magnesium-ion solid electrolyte possessing a high room temperature Mg+2 conductivity (~ 10−4 S/cm). MgSc2Se4 also has demonstrated considerably high electronic conductivity (10−5÷10−8 S/cm). Such high electronic conductivity substantially restricts the applications of show more
  • 16 Mar 2021 Journal Article Electric Power Systems Research

    Open source dataset generator for power quality disturbances with deep-learning reference classifiers

    Ram Machlev, A Chachkes, Juri Belikov, Yuval Beck, Yoash Levron
    In recent years power quality monitoring tools are becoming a necessity, and many studies focus on detection and classification of Power Quality Disturbances (PQD)s. However, presently a core obstacle that prevents the direct comparison of such classification techniques is the lack of a standard database that can be used as a benchmark. In this light, we propose here show more
  • 5 Mar 2021 Journal Article Journal of Fluid Mechanics

    The interaction of a particle and a polymer brush coating a permeable surface

    Coating of filtration membranes with a polymer brush holds great promise for efficiently preventing the deposition of fouling particles. The polymer chains are compressed by incoming particles, carried with the permeation flow towards the membrane, and consequently exert a repulsive force that acts to keep the particles away from the membrane surface. Here, we theoretically show more
  • 4 Mar 2021 Journal Article Nanoscale

    Bifunctional PGM-free metal organic framework-based electrocatalysts for alkaline electrolyzers: trends in the activity with different metal centers

    Wenjamin Moschkowitsch, Shmuel Gonen, Kapil Dhaka, Noam Zion, Hilah C Honig, Yoed Tsur, Maytal Caspary Toroker, Lior Elbaz
    In order to solely rely on renewable and efficient energy sources, reliable energy storage and production systems are required. Hydrogen is considered an ideal solution as it can be produced electrochemically by water electrolysis and renewably while no pollutants are released when consumed. The most common catalysts in electrolyzers are composed of rare and expensive show more
  • 2 Mar 2021 Journal Article Polymer International

    One-pot emulsion templating for simultaneous hydrothermal carbonization and hydrogel synthesis: porous structures, nitrogen contents and activation

    Porous carbons are of interest for a wide range of advanced‐technology ‘green’ energy applications including fuel cells, hydrogen storage, supercapacitors and batteries. Functional groups, heteroatoms and a more accessible hierarchical porous structure would be advantageous for many of these applications. This paper describes the generation of carbonaceous monoliths show more
  • 26 Feb 2021 Journal Article International Journal of Heat and Mass Transfer

    Acoustic-driven droplet evaporation: beyond the role of droplet-gas relative velocity

    Acoustic waves can be used for high-precision evaporation of droplets, allowing for fine control over the droplet diameter. Previous works considered the acoustic field as simply a means for generating relative velocity u1 between a droplet and its surrounding gas, which convects heat and mass from the droplet while oscillating. In the present work show more
  • 15 Feb 2021 Journal Article ChemistryOpen

    Atomic Layer Deposition (ALD) of Alumina over Activated Carbon Electrodes Enabling a Stable 4 V Supercapacitor Operation

    Designing high voltage (>3 V) and stable electrochemical supercapacitors with low self‐discharge is desirable for the applications in modern electronic devices. This work demonstrates a 4 V symmetric supercapacitor with stabilized cycling performance through atomic layer deposition (ALD) of alumina (Al2O3) on the surface of activated carbon (AC) show more
  • 9 Feb 2021 Chemsuschem

    Optimization of Ni-Co-Fe-Based Catalysts for Oxygen Evolution Reaction by Surface and Relaxation Phenomena Analysis

    Trimetallic double hydroxide NiFeCo-OH is prepared by coprecipitation, from which three different catalysts are fabricated by different heat treatments, all at 350 °C maximum temperature. Among the prepared catalysts, the one prepared at a heating and cooling rate of 2 °C min-1 in N2 atmosphere (designated NiFeCo-N2 -2 °C) displays the show more
  • 8 Feb 2021 Journal Article Energy

    Feedback for energy conservation: An info-gap approach

    Diverse types of feedback to energy consumers have been studied for reducing energy use. The effect of feedback on energy consumption ranges from nil to substantial, and formulating a feedback program faces great uncertainty. The challenge is to choose the feedback program to reliably achieve a specified reduction in energy use. The major uncertainty is in consumers’ show more
  • 26 Jan 2021 Journal Article Materials Horizons

    Bridging the thermodynamics and kinetics of temperature-induced morphology evolution in polymer/fullerene organic solar cell bulk heterojunction

    Artem Levitsky, Sebastian Alexander Schneider, Eugen Rabkin, Michael F Toney, Gitti L Frey
    The performance of organic solar cells (OSC) critically depends on the morphology of the active layer. After deposition, the active layer is in a metastable state and prone to changes that lead to cell degradation. Here, a high efficiency fullerene:polymer blend is used as a model system to follow the temperature-induced morphology evolution through a series of thermal show more
  • 22 Jan 2021 Journal Article Advanced Functional Materials

    High Performance Core/Shell Ni/Ni(OH)2 Electrospun Nanofiber Anodes for Decoupled Water Splitting

    Decoupled water splitting is a promising new path for renewable hydrogen production, offering many potential advantages such as stable operation under partial-load conditions, high-pressure hydrogen production, overall system robustness, and higher safety levels. Here, the performance of electrospun core/shell nickel/nickel hydroxide anodes is demonstrated in an show more