Oct 2022 • Forward Brillouin Scattering in Standard Optical Fibers: Single-Mode …, 2022
Avi Zadok, Hilel Hagai Diamandi, Yosef London, Gil Bashan
In this chapter, the analysis of forward stimulated Brillouin scattering in fibers comprised of multiple cores is presented. In such multi-core fibers, guided acoustic waves may be stimulated by optical fields in one core and induce photoelastic scattering of light waves in a different one. The photoelastic scattering leads to cross-phase modulation among optical fields in spatially distinct cores, which is mediated by the stimulation of guided acoustic modes. Cross-phase modulation may take place even among cores that are spaced far apart, where the direct coupling of optical power is arbitrarily weak. The process is quantified in terms of the spectrum of forward Brillouin scattering coefficient, defined earlier with respect to single-mode fibers. The spectrum of cross-phase modulation between the inner, on-axis core and an outer, off-axis core is mediated by guided acoustic modes of radial symmetry and torsional-radial …
Show moreOct 2022 • Biosensors
Ilan Merdler, Aviram Hochstadt, Eihab Ghantous, Lior Lupu, Ariel Borohovitz, David Zahler, Philippe Taieb, Ben Sadeh, Zeev Zalevsky, Javier Garcia-Monreal, Michael Shergei, Maxim Shatsky, Yoav Beck, Sagi Polani, Yaron Arbel
Background: The cost of heart failure hospitalizations in the US alone is over USD 10 billion per year. Over 4 million Americans are hospitalized every year due to heart failure (HF), with a median length of stay of 4 days and an in-hospital mortality rate that exceeds 5%. Hospitalizations of patients with HF can be prevented by early detection of lung congestion. Our study assessed a new contact-free optical medical device used for the early detection of lung congestion. Methods: The Gili system is an FDA-cleared device used for measuring chest motion vibration data. Lung congestion in the study was assessed clinically and verified via two cardiologists. An algorithm was developed using machine learning techniques, and cross-validation of the findings was performed to estimate the accuracy of the algorithm. Results: A total of 227 patients were recruited (101 cases vs. 126 controls). The sensitivity and specificity for the device in our study were 0.91 (95% CI: 0.86–0.93) and 0.91 (95% CI: 0.87–0.94), respectively. In all instances, the observed estimates of PPVs and NPVs were at least 0.82 and 0.90, respectively. The accuracy of the algorithm was not affected by different covariates (including respiratory or valvular conditions). Conclusions: This study demonstrates the efficacy of a contact-free optical device for detecting lung congestion. Further validation of the study results across a larger and precise scale is warranted.
Show moreOct 2022 • ECS Meeting Abstracts
Lior Elbaz, Wenjamin Moschkowitsch
Increasing the production capacity of electrical energy to fulfill the continuously rising global demand, while simultaneously trying to avoid greenhouse gas emissions in the process, and being environmentally sound, is one of the largest challenges of this era.One way to achieve it is to rely on hydrogen for energy storage. Nowadays, most of the hydrogen produced is mainly from fossil fuels, and the emission of detrimental gasses is only shifted. To get to a true green hydrogen, it is necessary to produce it in emissions-free processes.One method to achieve this is to use renewable energies in combination with electrochemical water electrolyzers, in which two distinct chemical reactions take place: the cathodic hydrogen evolution reaction (HER) and the anodic oxygen evolution reaction (OER). Both reaction require catalysts to execute at high rates, and while the HER is considered to be relatively facile and takes …
Show moreOct 2022 • ACS Applied Materials & Interfaces
Anat Itzhak, Xu He, Adi Kama, Sujit Kumar, Michal Ejgenberg, Antoine Kahn, David Cahen
The interfaces between inorganic selective contacts and halide perovskites (HaPs) are possibly the greatest challenge for making stable and reproducible solar cells with these materials. NiOx, an attractive hole-transport layer as it fits the electronic structure of HaPs, is highly stable and can be produced at a low cost. Furthermore, NiOx can be fabricated via scalable and controlled physical deposition methods such as RF sputtering to facilitate the quest for scalable, solvent-free, vacuum-deposited HaP-based solar cells (PSCs). However, the interface between NiOx and HaPs is still not well-controlled, which leads at times to a lack of stability and Voc losses. Here, we use RF sputtering to fabricate NiOx and then cover it with a NiyN layer without breaking vacuum. The NiyN layer protects NiOx doubly during PSC production. Firstly, the NiyN layer protects NiOx from Ni3+ species being reduced to Ni2+ by Ar plasma …
Show moreOct 2022 • Protein Science
Renana Schwartz, Sharon Ruthstein, Dan Thomas Major
Copper is an essential element in nature but in excess it is toxic to the living cell. The human metallochaperone Atox1 participates in copper homeostasis and is responsible for copper transmission. In a previous multiscale simulation study, we noticed a change in the coordination state of the Cu(I) ion, from 4 bound cysteine residues to 3, in agreement with earlier studies. Here we perform and analyse classical molecular dynamic simulations of various coordination states: 2, 3, and 4. The main observation is an increase in protein flexibility as a result of a decrease in coordination state. Additionally, we identified several populated conformations that correlate well with double electron‐electron resonance distance distributions or an X‐ray structure of Cu(I)‐bound Atox1. We suggest that the increased flexibility might benefit the process of ion transmission between interacting proteins. Further experiments can …
Show moreOct 2022 • Forward Brillouin Scattering in Standard Optical Fibers: Single-Mode …, 2022
Avi Zadok, Hilel Hagai Diamandi, Yosef London, Gil Bashan
Experimental characterization and applications of forward Brillouin scattering in various types of optical fibers are presented. Measurements are compared with the predictions of analysis and calculations whenever possible. Results include the forward Brillouin scattering spectra of bare and coated single-mode fibers, multi-core fibers, and polarization-maintaining fibers. Both intra-modal and inter-modal process in polarization-maintaining fibers are reported. The contributions of radial and torsional-radial modes are identified and classified. The interplay of forward Brillouin scattering and the Kerr effect is characterized as well. Position-integrated, point-measurement, and spatially distributed analyses of liquid media outside the fiber are demonstrated. The sensing of surrounding media is enabled by forward Brillouin scattering processes, even though guided light does not come in contact with such media. The …
Show moreOct 2022 • Optics Express
Keren Shemer, Gil Bashan, Elad Zehavi, Hilel Hagai Diamandi, Alon Bernstein, Kavita Sharma, Yosef London, David Barrera, Salvador Sales, Arik Bergman, Avi Zadok
Forward Brillouin scattering interactions support the sensing and analysis of media outside the cladding boundaries of standard fibers, where light cannot reach. Quantitative point-sensing based on this principle has yet to be reported. In this work, we report a forward Brillouin scattering point-sensor in a commercially available, off-the-shelf multi-core fiber. Pump light at the inner, on-axis core of the fiber is used to stimulate a guided acoustic mode of the entire fiber cross-section. The acoustic wave, in turn, induces photoelastic perturbations to the reflectivity of a Bragg grating inscribed in an outer, off-axis core of the same fiber. The measurements successfully analyze refractive index perturbations on the tenth decimal point and distinguish between ethanol and water outside the centimeter-long grating. The measured forward Brillouin scattering linewidths agree with predictions. The acquired spectra are unaffected by forward Brillouin scattering outside the grating region. The results add point-analysis to the portfolio of forward Brillouin scattering optical fiber sensors.
Show moreOct 2022 • Journal of The Electrochemical Society
Shalev Blanga, Reut Yemini, Eti Teblum, Merav Nadav Tsubery, Sarah Taragin, Malachi Noked
Lithium-sulfur batteries (LSBs) are considered a very attractive alternative to lithium-ion batteries due to their high theoretical capacity and the low cost of the active materials. However, the realization of LSBs remains hostage to many challenges associated with the cathode and anode response to the electrochemical conditions inside the battery cell. While working with LSBs, elemental sulfur undergoes multielectron reduction reactions until it is reduced to Li2S. The intermediate long chain lithium-polysulfide (LiPS) species are soluble, and hence diffuse through the electrolyte solution from the cathode side to the anode. This “shuttle” phenomenon is considered to be one of the main issues of LSB. Most effort in investigating LSBs has focused on the cathode side while few have considered the importance of the lithium anode reversibility and the separator role in preventing the “shuttle” phenomenon. In the current …
Show moreOct 2022 • Optics Continuum
Matan Slook, Saawan Kumar Bag, Moshe Katzman, Dvir Munk, Yuri Kaganovskii, Michael Rosenbluh, Naor Inbar, Inbar Shafir, Leroy Dokhanian, Maayan Priel, Mirit Hen, Elad Zehavi, Avi Zadok
Silicon-photonic integrated circuits are a pivotal technology for the continued growth of data communications. A main task of silicon photonics is the wavelength division multiplexing of communication channels to aggregate bandwidths that exceed the working rates available in electronics. In this work, we design and implement a 16-channel, wavelength division multiplexing device in silicon-on-insulator. The device operates at the O-band wavelengths, centered at 1310 nm, which are favored by many data center applications. The spacing between adjacent channels is 0.96 nm (167 GHz), close to those of dense wavelength division multiplexing standards in the 1550 nm wavelength range (C band). The layout consists of 15 Mach-Zehnder interferometers, cascaded in a four-stage tree topology. The differential phase delay within each interferometer is precisely trimmed post-fabrication, through local illumination of a photosensitive upper cladding layer of As 2 Se 3 chalcogenide glass. Trimming is performed subject to closed-loop feedback of transfer functions measurements. The devices can be useful in data center optical communications.
Show moreOct 2022 • Protein Science
Renana Schwartz, Sharon Ruthstein, Dan Thomas Major
Copper is an essential element in nature but in excess it is toxic to the living cell. The human metallochaperone Atox1 participates in copper homeostasis and is responsible for copper transmission. In a previous multiscale simulation study, we noticed a change in the coordination state of the Cu(I) ion, from 4 bound cysteine residues to 3, in agreement with earlier studies. Here we perform and analyse classical molecular dynamic simulations of various coordination states: 2, 3, and 4. The main observation is an increase in protein flexibility as a result of a decrease in coordination state. Additionally, we identified several populated conformations that correlate well with double electron‐electron resonance distance distributions or an X‐ray structure of Cu(I)‐bound Atox1. We suggest that the increased flexibility might benefit the process of ion transmission between interacting proteins. Further experiments can …
Show moreOct 2022 • Scientific Reports
Doron Duadi, Nadav Shabairou, Adi Primov-Fever, Zeev Zalevsky
Cilia motion is an indicator of pathological-ciliary function, however current diagnosis relies on biopsies. In this paper, we propose an innovative approach for sensing cilia motility. We present an endoscopic configuration for measuring the motion frequency of cilia in the nasal cavity. The technique is based on temporal tracking of the reflected spatial distribution of defocused speckle patterns while illuminating the cilia with a laser. The setup splits the optical signal into two channels; One imaging channel is for the visualization of the physician and another is, defocusing channel, to capture the speckles. We present in-vivo measurements from healthy subjects undergoing endoscopic examination. We found an average motion frequency of around 7.3 Hz and 9.8 Hz in the antero-posterior nasal mucus (an area rich in cilia), which matches the normal cilia range of 7–16 Hz. Quantitative and precise measurements of …
Show moreOct 2022 • Biomedical Photonics for Diabetes Research
Nisan Ozana, Zeev Zalevsky
241 11.3 243 11.4 Magneto-Optic Effect-Based Measurements..................................................................... 245 11.5 Speckle-Based Sensing of Chemicals by an Acoustic Excitation in Aqueous Solutions... 249 Remote Sensing of Tissue Perfusion in the Lower Limbs.................................................. 250 11.6 11.7 Summary............................................................................................................................ 251 252 Acknowledgments References
Show moreOct 2022 • Forward Brillouin Scattering in Standard Optical Fibers: Single-Mode …, 2022
Avi Zadok, Hilel Hagai Diamandi, Yosef London, Gil Bashan
Polarization-maintaining fibers support guided acoustic modes that are more complex than those of single-mode fibers, due to the presence of strain rods. Forward Brillouin scattering interactions in those fibers can be intra-modal as well as inter-modal. Intra-modal interactions involve the stimulation of guided acoustic waves by a pair of optical fields that co-propagate in a common principal axis. The intra-modal processes can lead to phase modulation of co-polarized optical probe signals, similar to standard single-mode fibers. The forward Brillouin scattering spectra differ between the two axes. In addition, acoustic modes stimulated through an intra-modal process in one axis may also modulate a probe wave in the orthogonal axis. Such inter-polarization cross-phase modulation is analogous to the dynamic gratings of backward Brillouin scattering in polarization-maintaining fibers. In inter-modal forward Brillouin …
Show moreOct 2022 • Communications Materials
Isaac Buchine, Irit Rosenhek-Goldian, Naga Prathibha Jasti, Davide R Ceratti, Sujit Kumar, David Cahen, Sidney R Cohen
Humidity is often reported to compromise the stability of lead halide perovskites or of devices based on them. Here we measure the humidity dependence of the elastic modulus and hardness for two series of lead halide perovskite single crystals, varying either by cation or by anion type. The results reveal a dependence on bond length between, hydrogen bonding with, and polarizability/polarization of these ions. The results show an intriguing inverse relation between modulus and hardness, in contrast to their positive correlation for most other materials. This anomaly persists and is strengthened by the effect of humidity. This, and our overall findings are ascribed to the materials’ unique atomic-scale structure and properties, viz nano-polar domains and strong dynamic disorder, yet high-quality average order. Our conclusions are based on comparing results obtained from several different nano-indentation …
Show moreOct 2022 • Advanced Science
Tianju Fan, Yujie Wang, Villa Krishna Harika, Amey Nimkar, Kai Wang, Xiaolang Liu, Meng Wang, Leimin Xu, Yuval Elias, Hadar Scalar, Munseok S Chae, Yonggang Min, Yuhao Lu, Netanel Shpigel, Doron Aurbach
Among extensively studied Li‐ion cathode materials, LiCoO2 (LCO) remains dominant for portable electronic applications. Although its theoretical capacity (274 mAh g−1) cannot be achieved in Li cells, high capacity (≤240 mAh g−1) can be obtained by raising the charging voltage up to 4.6 V. Unfortunately, charging Li‐LCO cells to high potentials induces surface and structural instabilities that result in rapid degradation of cells containing LCO cathodes. Yet, significant stabilization is achieved by surface coatings that promote formation of robust passivation films and prevent parasitic interactions between the electrolyte solutions and the cathodes particles. In the search for effective coatings, the authors propose RbAlF4 modified LCO particles. The coated LCO cathodes demonstrate enhanced capacity (>220 mAh g−1) and impressive retention of >80/77% after 500/300 cycles at 30/45 °C. A plausible mechanism …
Show moreOct 2022 • Journal of The Electrochemical Society
Lautaro Nicolás Acosta, Guillermo Garaventta, Mikhael Levi, Doron Aurbach, Victoria Flexer
Lithium-ion batteries are commonly charged following the constant current-constant voltage (CC-CV) protocol. Current flow during charging implies an equivalent ionic flow through the battery materials. Intercalation and de-intercalation of Li+ are accompanied by concentration gradients that are reflected by the rise in the cells' potentials that is required to maintain the constant current during the CC regime. In this work, two new pulsed charging protocols were tested. First, a square current pulse is applied to the cell until the cut-off voltage is reached, followed by a pulsed square voltage protocol (PV). The second methodology keeps the same current pulse; however, after the limiting voltage was reached, the pulsing regime consisted in alternating between a maximum voltage value and a minimum, non-zero, constant current value. Different voltage pulse widths and frequencies were tested, in order to study the …
Show moreOct 2022 • arXiv preprint arXiv:2210.07732
Yakov Bloch, Eliahu Cohen
The Cramer-Rao bound, satisfied by classical Fisher information, a key quantity in information theory, has been shown in different contexts to give rise to the Heisenberg uncertainty principle of quantum mechanics. In this paper, we show that the identification of the mean quantum potential, an important notion in Bohmian mechanics, with the Fisher information, leads, through the Cramer-Rao bound, to an uncertainty principle which is stronger, in general, than both Heisenberg and Robertson-Schrodinger uncertainty relations, allowing to experimentally test the validity of such an identification.
Show moreOct 2022 • Materials Research Bulletin
Naftali Kanovsky, Sarit Cohen, Shlomo Margel
Superhydrophobic coatings on polymeric films are in high demand due to their various real-world applications in a number of different fields. However, reported coatings lack durability or have complicated processes rendering them impractical. Here, tetraethylorthosilicate is polymerized via a modified Stöber method in the presence of a corona treated PP film (in-situ) which results in a thin silica-structured layer, covalently bonded to the PP film. Fluorocarbon silanes are then further reacted with the silica layer. The high surface roughness of the silica structures and low surface energy of the fluorocarbon silanes produce superhydrophobic surfaces. PP films coated with flake-like silica structures resulted in higher surface roughness and superhydrophobicity than the particle-like coating. Additionally, the flake-like silica coating exhibited good self-cleaning properties and durability to sandpaper abrasion tests. This …
Show moreOct 2022 • Journal of Personalized Medicine
Olga Girshevitz, Noa Cohen-Sinai, Alon Zahavi, Yoav Vardizer, Dror Fixler, Nitza Goldenberg-Cohen
We aimed to evaluate the types and concentrations of trace elements in tears of individuals living in urban and rural environments using particle induced X-ray emission (PIXE) and the possible association with exposure to air pollution and suggest a novel method for tear-based biomonitoring studies. This cross-sectional pilot study comprised 42 healthy subjects, 28 living in a rural area and 14 in an industrial city. Tears were collected with Schirmer paper and characterized by PIXE. Trace element concentrations from both eyes were averaged together with environmental pollution data. Main outcome measures were between-group differences in types and concentrations of trace elements in tears and comparison to environmental data. The rural group included 12/28 men, mean age 45.2 ± 14.8 years. The urban group consisted of 11/14 men of mean age 27 ± 5.9 years. Six rural and all urban were active smokers. Air pollution data showed more toxic elements in the rural environment. On PIXE analysis, chlorine, sodium, and potassium were found in similar concentrations in all samples. Normalizing to chlorine yielded higher values of aluminum, iron, copper, and titanium in the rural group; aluminum was found only in the rural group. The higher levels of certain trace elements in the rural group may, in part, be a consequence of exposure to specific environmental conditions. No direct association was found with air pollution data. PIXE is useful to analyze trace elements in tears, which might serve as a marker for individual exposure to environmental pollutants in biomonitoring studies.
Show moreOct 2022 • ACS nano
Avraham Twitto, Chen Stern, Michal Poplinger, Ilana Perelshtein, Sabyasachi Saha, Akash Jain, Kristie J Koski, Francis Leonard Deepak, Ashwin Ramasubramaniam, Doron Naveh
Metal–semiconductor interfaces are ubiquitous in modern electronics. These quantum-confined interfaces allow for the formation of atomically thin polarizable metals and feature rich optical and optoelectronic phenomena, including plasmon-induced hot-electron transfer from metal to semiconductors. Here, we report on the metal–semiconductor interface formed during the intercalation of zero-valent atomic layers of tin (Sn) between layers of MoS2, a van der Waals layered material. We demonstrate that Sn interaction leads to the emergence of gap states within the MoS2 band gap and to corresponding plasmonic features between 1 and 2 eV (0.6–1.2 μm). The observed stimulation of the photoconductivity, as well as the extension of the spectral response from the visible regime toward the mid-infrared suggests that hot-carrier generation and internal photoemission take place.
Show moreOct 2022 • Nature communications
Asaf Ashkenazy-Titelman, Mohammad Khaled Atrash, Alon Boocholez, Noa Kinor, Yaron Shav-Tal
The changes occurring in mRNA organization during nucleo-cytoplasmic transport and export, are not well understood. Moreover, directionality of mRNA passage through the nuclear pore complex (NPC) has not been examined within individual NPCs. Here we find that an mRNP is compact during nucleoplasmic travels compared to a more open structure after transcription and at the nuclear periphery. Compaction levels of nuclear transcripts can be modulated by varying levels of SR proteins and by changing genome organization. Nuclear mRNPs are mostly rod-shaped with distant 5'/3'-ends, although for some, the ends are in proximity. The latter is more abundant in the cytoplasm and can be modified by translation inhibition. mRNAs and lncRNAs exiting the NPC exhibit predominant 5’-first export. In some cases, several adjacent NPCs are engaged in export of the same mRNA suggesting 'gene gating' …
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