Altering Mechanical Properties to Improve Electrode Contacts by Organic Modification of Silica-Based Ionogel Electrolytes for Sodium-Ion Batteries

Sodium-ion batteries (SIBs) are a possible candidate to create safe, sustainable, and cost-effective batteries. Solid sodium-ion conducting organically modified ionogel electrolytes are investigated. Silica-based ionogels typically consist of an ionic liquid electrolyte (ILE) confined within a silica matrix and possess high thermal stability, good ionic conductivity, safety, and good electrochemical stability. However, they readily deteriorate when stress is applied, decreasing the electrolyte's and battery's overall performance. The mechanical characteristics of silica can be improved using organic moieties, creating Ormosils®. Silica-based ionogels with phenyl-modified silanes improve the mechanical characteristics by a reduction of their Young's modulus (from 29 to 6 MPa). This is beneficial to the charge-transfer resistance, which decreases after implementing the electrolyte in half cells, demonstrating the improved interfacial contact. Most importantly, the phenyl groups change the interacting species at the silica interface. Cationic imidazolium species pi-stacked to the phenyl groups of the silica matrix, pushing the anions to the bulk of the ILE, which affects the ionic conductivity and electrochemical stability, and might affect the quality of the SEI in half cells. In essence, the work at hand can be used as a directory to improve mechanical characteristics and modify and control functional properties of ionogel electrolytes.     

Wave equation-based imaging of mode converted waves in ultrasonic NDI, with suppressed leakage from nonmode converted waves

The value of imaging techniques in ultrasonic nondestructive inspection (NDI) to find and characterize defects in steel components has already been demonstrated. The imaging techniques based on the integral representation of the wave equation, the Rayleigh integrals for wave field extrapolation, are becoming feasible and attractive due to advances in array technology and due to faster computers. Known implementations are the total focusing method (TFM), the synthetic aperture focusing method (SAFT), and the inverse wave field extrapolation method (IWEX). In principle, these techniques compensate propagation effects from sources to a scatterer such as a defect and propagation effects from the scatterer to receivers. Currently, this approach is applied to wave fronts of single modes (pure longitudinal or pure transversal). In practice, multiple wave fronts from the scatterer will be received as a result of mode conversion. These arrivals will not have the same arrival time because of the difference in sound velocity between longitudinal and transversal waves. Images of mode converted waves are obtained by choosing the appropriate sound velocity that corresponds with the mode-converted scattered wave in the imaging process. Therefore, the nonmode converted waves will image as leakage artifacts in the mode-converted images, and vice versa. This may lead to false interpretations. In this paper, such artifacts will be identified and explained with the help of an analytical example. Measurements from steel test pieces with a 4 MHz linear array transducer with 64 elements will be used to demonstrate the artifacts. Furthermore, a procedure to predict the artifacts and the subsequent suppression from the input measurements will be presented and demonstrated.     

Sequential Partial Ozonation for the Treatment of Wastewater Concentrate: Practical Implications From a Conventional and (Eco) Toxicological Perspective

This article compares multi-stage ozonation-biological treatment processes [O₃ - Biodegradation - O₃ - Biodegradation] and conventional partial ozonation processes [O₃ - Biodegradation] for the removal of S_COD and toxicity from a recalcitrant and toxic wastewater concentrate. Both direct (pH 7.5) and advanced (pH 11.5) ozonation are evaluated. Short-term estimation methods for biodegradability (respirometry) and toxicity (30 min Vibrio fisheri luminescence inhibition) are evaluated for their use in process control.     

A kinetic model for multicomponent wastewater substrate removal by partial ozonation and subsequent biodegradation

A kinetic model for multicomponent substrate removal by the partial ozonation process is presented. The model consists of a component describing the co-evolution of COD and BOD as a function of ozone dosage and a mass transfer based component describing ozone dosage as a function of time. A multiple zero order reaction concept is used to describe the multicomponent kinetic behaviour. The model has been verified experimentally by comparing stoichiometric ratio and ozone reaction rate of conventional partial ozonation processes and partial ozonation processes with intermittent biodegradation. The model is found to effectively describe the change in stoichiometry and reaction rate that typically occurs during ozonation processes. Intermittent biodegradation is found to have no effect on the instantaneous stoichiometric ratio or the instantaneous ozone reaction rate. This implicates that intermittent BOD removal results in an additional decrease in required ozonation time and ozone demand compared to the conventional partial ozonation process and in addition to the expected decrease resulting from BOD removal.     

A scalable WebRTC-based framework for remote video collaboration applications

Multimedia Tools and Applications - Remote video collaboration is common nowadays in conferencing, telehealth and remote teaching applications. To support these low-latency and interactive use...     

Object wave reconstruction by phase-plate transmission electron microscopy

A method is described for the reconstruction of the amplitude and phase of the object exit wave function by phase-plate transmission electron microscopy. The proposed method can be considered as in-line holography and requires three images, taken with different phase shifts between undiffracted and diffracted electrons induced by a suitable phase-shifting device. The proposed method is applicable for arbitrary object exit wave functions and non-linear image formation. Verification of the method is performed for examples of a simulated crystalline object wave function and a wave function acquired with off-axis holography. The impact of noise on the reconstruction of the wave function is investigated.