BINA

Fast charging is regarded as one of the most coveted technologies for commercial Li-ion batteries (LIBs), but the lack of suitable electrolytes with sufficient ionic conductivity and effective passivation properties hinders its development. Herein, we designed a mixed-solvent electrolyte (1 M LiPF6 in fluoroethylene carbonate/acetonitrile, FEC/AN, 7/3 by vol.) to overcome these two limitations by achieving an FEC-dominated solvation structure and an AN-rich environment. The specific AN-assisted Li+ hopping transport behavior shortens the Li+ diffusion time, doubling the ionic conductivity to 12 mS cm–1, thus endowing the graphite anode with >300 mAh g–1 at 20C and reversible (de)intercalation over a wide temperature range (from −20 to +60 °C). Furthermore, the designed electrolyte triples the capacity of the 1 Ah graphite||LiNi0.8Mn0.1Co0.1O2 (NMC811) pouch cells at 8C in comparison with the commercial …

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 …

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 …

The process of forward stimulated Brillouin scattering in standard single-mode fibers is described. The analysis brings together the electrostrictive stimulation of guided acoustic modes by a pair of co-propagating optical fields and the photoelastic scattering of the same two optical fields by the acoustic wave. The propagation of the optical fields is formulated in terms of nonlinear polarization components and coupled nonlinear wave equations. The solutions to the equation signify the coupling of optical power from the higher-frequency optical wave component to the lower-frequency one. Coupling is quantified by a nonlinear coefficient, with units of W−1 × m−1, the same one that was found earlier to describe spontaneous scattering processes. The stimulated Brillouin scattering between the pair of tones is also associated with the generation of spectral sidebands of increasing orders. The Brillouin scattering …

In the first chapter of this book, the opto-mechanical effect of forward Brillouin scattering is introduced within a broader context of propagation effects in fibers and of interactions between optical and acoustic waves. A review of linear and nonlinear scattering phenomena is provided, including the mechanisms of Rayleigh, Raman, and Brillouin scattering, and the optical Kerr effect. Scattering from short-period and long-period grating devices is discussed as well. The potential applications and implications of the various mechanisms in optical fiber communications, sensing, signal processing, and lasing are briefly addressed. Next, the physical principles of opto-mechanics are introduced. These include the stimulation of elastic waves by electrostrictive bulk forces and radiation pressures and the scattering of optical waves through photoelasticity and moving boundary effects. Specific formalisms are developed for the …

We present a complete numerical analysis and simulation of the full spatio-temporal dynamics of Kerr-lens mode-locking in a laser. This dynamic, which is the workhorse mechanism for generating ultrashort pulses, relies on the intricate coupling between the spatial nonlinear propagation and the temporal nonlinear compression. Our numerical tool emulates the dynamical evolution of the optical field in the cavity on all time-scales: the fast time scale of the pulse envelope within a single round trip, and the slow time-scale between round-trips. We employ a nonlinear ABCD formalism that fully handles all relevant effects in the laser, namely—self focusing and diffraction, dispersion and self-phase modulation, and space-dependent loss and gain saturation. We confirm the validity of our model by reproducing the pulse-formation in all aspects: The evolution of the pulse energy, duration, and gain during the entire cavity buildup, demonstrating the nonlinear mode competition in full, as well as the dependence of the final pulse in steady state on the interplay between gain bandwidth, dispersion, and self-phase modulation. The direct observation of the nonlinear evolution of the pulse in space-time is a key enabler to analyze and optimize the Kerr-lens mode-locking operation, as well as to explore new nonlinear phenomena.

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.

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 …

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.

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 …

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 …

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

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 …

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 …

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 …

MethodRat pups' brains were dissected and placed on a chilled petri dish. They then entered the experimental protocol. The suspended synaptosomes were divided equally into four experimental groups (control, high potassium" surrogate to hypoxic stimulation," cocaine, and cocaine+ high K). Reversed-phase high-performance liquid chromatography analyzed glutamate with fluorescent detectionResultsThe glutamate level was lowest in the cocaine-only group, with a level of 1.96× 10 4, compared to the control and high potassium group. However, combining cocaine with high potassium seemed to generate a synergistic effect, achieving the highest glutamate level of all groups with a value of 5.31× 10 4.

Most of the charge transport properties in halide perovskite absorbers are measured by transient measurements with pulsed excitations; however, most solar cells in real life function in steady-state conditions. In contrast to working devices that include selective contacts, steady-state measurements need as high as possible photoconductivity (σph), which is typically restricted to the absorber alone. In this paper, we enabled steady-state charge transport measurement using atomic layer deposition (ALD) to grow a conformal, ultra-thin (~4nm) ZnO electron transport layer that is laterally insulating due to its thickness. Due to the highly alkaline behavior of the ZnO surfaces, it readily reacts with Halide Perovskites (HaP). ALD process was used to form an Aluminum oxynitride (AlON) thin (~2nm) layer that passivates the ZnO-HaP interface. We show that the presence of the AlON layer prevents HaP degradation caused by …

Alkaline electrolyte membrane electrolyzers are a promising technology to efficiently produce clean hydrogen without the use of critical raw materials. At the heart of these electrolyzers are the electrocatalysts, which facilitate the cathodic and anodic reactions, with the latter oxygen evolution reaction (OER) being the most sluggish. In recent years, aerogels have become a very well-studied class of materials due to their unique properties, including very high surface area. Until now, aerogels have not been used to catalyze the OER by themselves but were mainly considered catalyst supports. Here, mixed-metal nickel–iron oxide aerogels were synthesized with a modified epoxide route synthesis and tested as OER catalysts. Depending on the Ni/Fe ratio, they show very high catalytic activity and low overpotential to reach 10 mA cm–2 (at η = 380 mV). This activity is beyond that of the existing state-of-the-art platinum …

The coherence holography offers an unconventional way to reconstruct the hologram where an incoherent light illumination is used for reconstruction purposes, and object encoded into the hologram is reconstructed as the distribution of the complex coherence function. Measurement of the coherence function usually requires an interferometric setup and array detectors. This paper presents an entirely new idea of reconstruction of the complex coherence function in the coherence holography without an interferometric setup. This is realized by structured pattern projections on the incoherent source structure and implementing measurement of the cross-covariance of the intensities by a single-pixel detector. This technique, named structured transmittance illumination coherence holography (STICH), helps to reconstruct the complex coherence from the intensity measurement in a single-pixel detector without an interferometric setup and also keeps advantages of the intensity correlations. A simple experimental setup is presented as a first step to realize the technique, and results based on the computer modeling of the experimental setup are presented to show validation of the idea.

An electrocatalyst composed of RuO2 surrounded by interfacial carbon, is synthesized through controllable oxidization‐calcination. This electrocatalyst provides efficient charge transfer, numerous active sites, and promising activity for pH‐universal electrocatalytic overall seawater splitting. An electrolyzer with this catalyst gives current densities of 10 mA cm−2 at a record low cell voltage of 1.52 V, and shows excellent durability at current densities of 10 mA cm−2 for up to 100 h. Based on the results, a mechanism for the catalytic activity of the composite is proposed. Finally, a solar‐driven system is assembled and used for overall seawater splitting, showing 95% Faraday efficiency.