Liquid Constituents Research Articles

Do ETFs increase the comovements of their underlying assets? Evidence from a switch in ETF replication technique

We investigate the impact of Exchange-Traded Funds (ETFs) on the comovements of their constituent securities using a novel identification that exploits the switch from synthetic to physical replication of a large French ETF. After the switch, constituent stocks experience greater commonality, in both returns and liquidity. For both the full sample of ETF constituents and the least liquid ETF constituents, a larger part of the variation in individual stock returns or liquidity is explained by market-wide variations. We present evidence that ETF creation and redemption is the transmission mechanism of the comovements. Moreover, we show that the comovements do not appear excessive.

Exploring the Effect of Ionic Liquid Conformation on the Selective CO2 Capture of Supported Ionic Liquid-Phase Adsorbents Based on ZIFs.

The CO2 adsorption capacity and the CO2/N2 selectivity of a series of Supported Ionic Liquid-Phase adsorbents (SILPs), including the novel inversely structured SILP "Inverse SILPs", are thoroughly investigated. ZIF-8, ZIF-69 and ZIF-70 were involved as the solid matrix, while ILs, having tricyanomethanide (TCM) as an anion and alkyl-methylimidazolium of different alkyl chain lengths (C2, C6, C8) as a cation, were used as the liquid constituents of the SILPs. The ultimate target of the work was to ratify a few recently reported cases of enhanced CO2 absorptivity in ILs due to their incorporation in ZIFs and to corroborate phenomena of CO2/N2 selectivity improvements in ZIFs, due to the presence of ILs. This ambiguity originates from the vague assumption that the pores of the ZIF are filled with the IL phase, and the free pore volume of a SILP is almost zero. Yet, through the integration of theoretical predictions with N2 porosimetry analysis of an actual sample, it is suggested that a thin layer of IL covered the exterior surface of a ZIF crystal. This layer could act as an impermeable barrier for N2, inhibiting the gas molecules from reaching the empty cavities laying underneath the liquid film during porosimetry analysis. This consideration is based on the fact that the solubility of N2 in the IL is very low, and the diffusivity at 77 K is negligible. In this context, the observed result reflects an averaged adsorptivity of both the IL phase and the empty pores of the ZIF. Therefore, it is incorrect to attribute the adsorption capacity of the SILP solely to the mass of the IL that 'hypothetically' nests inside the pore cavities. In fact, the CO2 adsorption capacity of SILPs is always less than the average adsorptivity of an ideal ZIF/IL mixture, where the two phases do not interact. This reduction occurs because some ZIF pores may become inaccessible, particularly when the IL forms a layer on the pore walls, leaving only a small empty core accessible to CO2 molecules. Additionally, the IL layer masks the active sites on the ZIF's pore walls. It should also be noted that the CO2/N2 selectivity increases only when the ZIF's pores are completely filled with the IL phase. This is because ILs have a higher CO2/N2 selectivity compared to the bare ZIF.

Evolution of asphalt performance under the coupled aging of ultraviolet, high temperature and water

During the service of asphalt pavement, it is affected by natural environmental factors for a long time, and the pavement performance declined. In order to simulate the cumulative effects of multiple aging components, the indoor "ultraviolet radiation, high temperature and water" multi-factor cyclic coupling aging test was designed. The properties of asphalt during cyclic coupled aging were measured by conventional physical properties tests, photoelectric colorimetric tests, and Fourier Transform Infrared Spectroscopy test. Then the surface morphology of asphalt was observed by camera and optical microscope. After asphalt aged, a large number of oxidation functional groups were formed, causing asphalt to become hard and brittle, adhesion to diminish, and surface roughness to increase. Ultraviolet light and high temperatures led to the exudation and dissolution of the liquid constituents within the asphalt, which were subsequently washed away by water. The thermal stress induced the shrinkage and wrinkle of the asphalt film, resulting in the formation of cracks. Under high temperatures, a limited number of cracks could potentially self-repair during the early stages of aging. Nevertheless, as the aging process progressed, the self-healing capacity of the asphalt diminished, leading to the widening and deepening of cracks. Concurrently, water infiltrated along the cracks into the inner layers of the asphalt, exacerbating the degradation of its properties.

A Mixture Model With Slip Velocity for Saturated Granular‐Liquid Free‐Surface Flows

AbstractIn this paper, a model is presented for modeling saturated granular‐liquid free‐surface flows, in which the volume‐averaged mixture bulk velocity is employed to derive the balance equations for the mass and momentum of mixture flow. Additionally, an evolution equation of the slip velocity between granular‐and liquid constituents is derived to describe the separation between these constituents. The frictional‐collisional constitutive relation for granular‐constituent is employed to determine the stress due to particles interaction. The governing equations for mixture flows are numerically solved by a finite difference two‐step projection method. The volume of fluid (VOF) method is employed to track the free surface of the mixture flow in the present numerical model. Good agreements between numerical results and experimental data are observed by modeling the dam‐break process of granular‐liquid mixture flow, dam‐break waves over the saturated erodible beds and surge waves induced by submarine landslides along an inclined plane. Furthermore, the difference between the volume‐averaged mixture bulk velocity and mass‐averaged mixture bulk velocity is found to vary as the instinct density ratio of granular‐constituent and liquid‐constituent and the volumetric concentration ns of the granular‐constituent, and the evolution in the slip velocity during the process of the settlement of sediments is numerically analyzed.

Digital Multiphase Composites via Additive Manufacturing.

Mechanical properties of traditional engineering materials are typically coupled to each other, presenting a challenge to practitioners with multi-dimensional material property requirements. In this work, continuous, independent control over multiple mechanical properties is demonstrated in composite materials realized using additive manufacturing. For the first time, composites additively manufactured from rigid plastic, soft elastomer, and liquid constituents are experimentally characterized, demonstrating materials which span four orders of magnitude in modulus and two orders of magnitude in toughness. By forming analytical mappings between relative concentrations of constituents at the microscale and resulting macroscale material properties, inverse material design is enabled; the method is showcased by printing artifacts with prescribed toughness and elasticity distributions. The properties of these composites are placed in the context of biological tissues, showing they have promise as mechanically plausible tissuemimics.

(General Student Poster Award Winner, 1st Place) Accelerated Estimation of Chemical and Sensory Liquid Attributes Using an AI-Assisted Electrochemical Electronic Tongue

Electronic tongues based on arrays of potentiometric sensors bears promises for enabling portable and fast analysis of complex liquids by leveraging low-selectivity and high-sensitivity of the inherent sensing materials. Thus, they have been studied and developed to target multiple applications, including analysis of chemical compositions or for untargeted quality control in the food industry. A key element to enable practical use of electronic tongues, however, has often been the analysis and interpretation of their combinatorial response due to the cross-sensitivity of the employed sensors. Indeed, disentangling the effect of multiple liquid constituents on the potentiometric response is the main associated challenge. The present contribution aims at studying the feasibility and accuracy of employing this class of sensors to both the quantification of multiple analytes in water as well as prediction of sensory attributes in coffee samples. A proof-of-concept system comprises an integrated array of miniaturized polymeric sensors and an electronic board records 15 differential voltages, produced by the interaction with both ionic and organic constituents of liquids, and can transmit them via Bluetooth to an external device. An automated pipeline performs pre-processing, hand-crafted feature extraction and training of machine learning models that can be then deployed on the cloud or edge device (e.g., smartphone). The same array can be then reconfigured to address a new specific task by leveraging new potentiometric data collection and applying the automated data analysis. In particular, the device presented herein employed 16 polymeric sensors that were electrodeposited on conventional electroless nickel immersion gold (ENIG) electrodes. The conductive polymers (PEDOT, PPy, PANI and PAPBA) were synthesized by chronoamperometry or cyclic voltammetry and enriched with doping agents for enhanced sensitivity. Differential voltages between these polymeric sensors were measured during the transition of the sensor array from a reference solution to a test solution, thereby obviating the need for a conventional reference electrode. Indeed, the use of low-selective sensors for potentiometric measurements does not require integration of reference electrodes, which are known to be unpractical for remote sensing applications. The analysis of the potentiometric response revealed deviations from linear sensitivities, showing non-Nernstian voltage trends when varying concentration of target analytes. Training data were obtained by alternatively immersing the sensor array in reference (120 s) and test (60 s) solutions continuously using an automated test rig. In addition to the conventional approach of measuring the equilibrium potential after a certain settling time, the complete evolution of the potentiometric signal in time could provide richer information that could be useful for building calibration models. Hence, hand-crafted features were extracted from time series recorded during sensor training in order to reduce the dimension of data and describe the complete voltage perturbation of the sensor during transition between reference and test solution. If exposed to enough “known liquid examples”, the sensor array can learn patterns to perform accelerated qualitative and quantitative analysis. The device has demonstrated enhanced discrimination of various mixtures and was proved able to predict beverage sensory properties after intensive training with samples with known sensory attributes. Firstly, the sensitivity to multiple ionic species was estimated in model mixtures obtained following an Orthogonal Experimental Design (OED) for a set of four metal ions, including Al3+, Cu2+, Na+ and Fe3+, and another set comprising Ca2+, Mg2+ and Na+. The former experiment demonstrated that non-linear regression models, such as a Random Forest of Extra Trees, can cope with non-linearity of the sensor response and yielded better performances than widely used multivariate regression model i.e., Multiple Linear Regression (MLR). The mean relative quantification error varied between 1% for Fe3+ and 44% for Na+ in the concentration range 1-10 mg/L. The second mixture set was used instead to unveil the cross-sensitive response of the sensor array, build a quantification model to predict major cations in mineral water and proving the importance of feature selection for data-driven sensors. Overall, the sensor showed comparable accuracy to ICP-MS (MRE 12-24%) but with a drastic reduction of cost and processing time. Finally, the same sensor array configuration was also used to test 12 coffee samples, which were also evaluated by a sensory panel through 5 taste attributes. Regression models were built to map instrument response to sensory data and Extra-Tree algorithm yielded the highest performances with a MRE varying from 8% to 21% depending on coffee sample and validation scheme. Thus, it was demonstrated that data-driven sensor arrays could be also valuable alternative tools for accelerated evaluation of beverage sensory characteristics and support food innovation processes. Figure 1

Modelling growth and formation of thrombi: a multiphasic approach based on the theory of porous media

AbstractAortic dissection (AD) has a high mortality rate. About 40% of the people with type B AD do not live for more than a month. The prognosis of AD is quite challenging. Hence, we present a triphasic model for the formation and growth of thrombi using the theory of porous media (TPM). The whole aggregate is divided into solid, liquid and nutrient constituents. The constituents are assumed to be materially incompressible and isothermal, and the whole aggregate is assumed to be fully saturated. Darcy’s law describes the flow of fluid in the porous media. The regions with thrombi formation are determined using the solid volume fraction. The velocity- and nutrient concentration-induced mass exchange is defined between the nutrient and solid phases. We introduce the set of equations and a numerical example for thrombosis in type B AD. Here we study the effects of different material parameters and boundary conditions. We choose the values that give meaningful results and present the model’s features in agreement with the Virchow triad. The simulations show that the thrombus grows in the low-velocity regions of the blood. We use a realistic 2-d geometry of the false lumen and present the model’s usefulness in actual cases. The proposed model provides a reasonable approach for the numerical simulation of thrombosis.

Efficacy of activated carbon filtration and ozonation to remove persistent and mobile substances – A case study in two wastewater treatment plants

Persistent and mobile (PM) substances are able to spread quickly in the water cycle and were thus identified as potentially problematic for the environment and water quality. If also toxic (PMT) or very persistent and very mobile (vPvM) their regulation under REACH as substances of very high concern is foreseen. Yet, knowledge on the effectiveness of advanced wastewater treatment in removing PM-substances from WWTP effluents is limited to few rather well-known chemicals. The occurrence and behavior of 111 suspected and known PM-substances was investigated in two wastewater treatment plants employing either powdered activated carbon (PAC, full-scale) or ozonation with subsequent sand/anthracite filtration (pilot-scale) and an additional granular activated carbon (GAC) filtration was investigated. 72 of the 111 PM-substances analyzed were detected at least once in the secondary effluent of either wastewater treatment plant, resulting in total concentrations of 104 μg/L and 40 μg/L, respectively. While PAC removed 32 % of PM-substances well, the total PM burden in the effluent was only reduced from 103 μg/L to 87 μg/L. Ozonation and the subsequent sand/anthracite filtration was able to reduce the PM burden in wastewater from 40 μg/L to 19 μg/L, showing a higher removal efficacy than PAC in this study. The additional GAC filtration further reduced the total PM-concentration to 13 μg/L. Among the investigated PM-chemicals detected were constituents of ionic liquids: The anion hexafluorophosphate was one of few chemicals that was detected in effluent concentrations >1 μg/L and could not be removed by the processes studied, showing that for some chemicals preventive actions may be required.

Multiphasic modelling of thrombus formation and growth based on the Theory of Porous Media

AbstractAortic dissection (AD) has a high mortality rate. 40% of the people with Type B Aortic Dissection do not live for more than a month. The prognosis of Aortic Dissection is quite challenging leading to an interest in computational methods to help with the decision‐making process for the treatment. The Theory of Porous Media (TPM) provides an excellent framework to describe the multiphasic structure of the thrombus. The whole aggregate is divided into solid, liquid and nutrient constituents. We assume the constituents to be materially incompressible, the whole aggregate to be fully saturated and under isothermal conditions. The balance equations of the constituents have coupling terms, also known as production terms, which take care of the interactions between the different phases. The volume fractions define the constituents. Therefore, the regions with thrombus are determined using the solid volume fraction. Darcy's law describes the flow of fluid in the porous media. We present the set of equations and a numerical example for thrombosis in Type B Aortic Dissection. We implement the equations in PANDAS, a finite element package designed to solve strongly coupled multiphase porous media problems.

Interactive effects of protonated nicotine concentration and device power on ENDS nicotine delivery, puff topography, and subjective effects.

Electronic nicotine delivery systems (ENDSs) produce an aerosol by heating a liquid that often contains nicotine. The nicotine can be protonated that may make the aerosol easier to inhale than freebase nicotine. This study's purpose is to determine, in cigarette smokers and ENDS users, the effects of three concentrations of protonated nicotine aerosolized at two different power settings. Forty-five participants (22 cigarette smokers and 23 ENDS users) completed some or all of six sessions that varied by liquid nicotine concentration (10, 15, or 30 mg/ml protonated nicotine) and device power (15 or 30 W). Participants took 10 puffs from each product and then used each product for 90 min ad libitum. Plasma nicotine concentration, subjective effects, and puff topography were measured. Results showed increases in plasma nicotine concentration in all conditions, with greater plasma nicotine increases in higher watt, higher nicotine concentration conditions, as well as greater nicotine delivery for ENDS users compared to cigarette smokers. For puff topography, puff duration and volume decreased as nicotine concentration and power increased, and ENDS users took longer and larger puffs than cigarette smokers. Participants rated the higher watt, higher nicotine concentration conditions as harsher and with more throat hit. Overall, these results suggest that device characteristics and liquid constituents interact to influence users' plasma nicotine delivery and should be considered together when regulating ENDS. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

New room temperature ionic liquids prepared from an old phosphine: Using branching and diastereomeric mixtures to inherently benefit physical properties

First reported in 1966–1967, the compound tri(2-ethylhexyl)phosphine appears to be a hidden gem for ionic liquids. Although this compound offers many potential intriguing properties that are inherent due to its branching and diastereomeric nature, there is only a single report employing this material as an ionic liquid constituent. Through quaternization and anion exchange, a total of 24 new room temperature ionic liquids were prepared containing bromide (Br−), bis(trifluoromethanesulfonyl)imide (Tf2N−), hexafluorophosphate (PF6−), and tetrafluoroborate (BF4−) anions. In addition to the usual analytical methods, the compounds’ physical properties such as density, solubility, viscosity, and surface tension were probed to ascertain their suitability for aerospace applications. Differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) were employed to study the thermal behavior of the materials focusing on phase transitions and degradation behavior. Remarkably, all ionic liquids prepared in this study are liquids at room temperature with relatively low viscosities and are soluble in many common organic solvents. Structure-property relationships were assessed, particularly focusing on the effect that the chain length appendage and/or anion type has on a given physical property. An updated synthetic procedure and characterization of the tri(2-ethylhexyl)phosphine starting material are provided. A new synthesis procedure for the starting material silver(I) tetrafluoroborate is also reported.

Solid‐Phase Extraction of the Aromatic By‐Products Obtained by Fast Pyrolysis of Pretreated Lignocellulose

AbstractPyrolysis is a recognized technology for lignocellulose conversion into bio‐based fuels, materials, and chemicals. In this work, pyrolysis liquids were obtained by fast pyrolysis of wood after pretreatment with diluted sulfuric acid. The pyrolysis liquids were separated by solid‐phase extraction with an anion exchange resin Lewatit VPOC 1074 as the stationary phase. The aromatic constituents of the pyrolysis liquids were adsorbed on the resin, while the sugar derivative fraction was eluted with water. Different desorption solvents were tested for batch and continuous elution of phenol derivatives. Most promising results were obtained for selective separation of phenol carboxylic acids by changing the ratio of water, methanol, and acetic acid in the solid‐phase extraction solvent system.

Study on Effectiveness of Intervention of a Vertical Flow Constructed Wetland in between Septic Tank and Soak Pit for the Treatment of Septic Tank Effluent

Septage comprises the solid and liquid constituents of any primary treatment system, including a Septic Tank. In this study, the wastewater collected from a septic tank is passed through a partially converted anaerobic filter, and a vertical flow constructed wetland (VFCW) before being sent to a soak pit. The main objective of this case study was to check the effectiveness of incorporating a VFCW between a septic tank and a soak pit to bring down the consequences created due to effluent seepage from soak pits to the groundwater. Conventionally, the effluent gets directly passed to soak pits after primary onsite treatment in the septic tank. The soak pit walls made of porous materials allow the gradual seepage of final effluent into the ground, polluting the groundwater reserves. We analyzed the septic tank effluent from 60 households wherein the effluent was let off into the soak pits. The various parameters analyzed with their averages were 393.83 ± 293.41 mg.L-1 for COD, 151.48 ± 94.37 mg.L-1 for BOD, 30.81 ± 13.05 mg.L-1 for NO3-, 23.35 ± 13.54 mg.L-1 for PO43-, 7.35 ± 0.31 for pH, 184.05 ± 163.20 mg.L-1 for TSS, 3.05 x 107± 2.04 x 108 CFU.100mL-1 for TC. Therefore, it is certain that the final effluent being sent into soak pits after primary treatment does not meet the Central Pollution Control Board (CPCB) discharge standards. In this case study, we were able to obtain final effluent values after VFCW treatment as 55.72 mg.L-1 for COD, 12.12 mg.L-1 for BOD, 10.2 mg.L-1 for NO3-, 3.74 mg.L-1 for PO43-, 7.41 for pH, 8.37 mg.L-1 for TSS, 379.27 mg.L-1 for TS and 51.9 CFU.100mL-1 for TC. With this case study, we were able to resolve this impediment by bringing down the values of all the parameters considered while analyzing under the limits of discharge standards set by CPCB. The removal efficiency of COD, BOD, NO3-, PO43-, pH, TSS, and TC after wetland was found to be 89.46%, 88.051, 63.484, 44.37%, 3.41%, 98.47%, 97.71%, 97.19% respectively. The study has proven that with the introduction of another decentralized treatment system between a septic tank and soak pit, it is safe to dispose of the effluent into soak pits, thereby reducing the chances of groundwater pollution considerably.

Effect of the interaction between wood constituents and swelling liquid on the creep properties of wood during drying

Abstract This study aimed to clarify the effect of the interactions between the swelling liquid and wood constituents on the creep behavior during drying. Creep tests were conducted during drying of four sample groups (untreated, acetylated, delignified, and hemicellulose-extracted samples) that were swollen using water, one organic liquid, or water-organic mixtures. The largest creep deformation was measured for the hemicellulose-extracted samples, followed by delignified, untreated, and acetylated samples. Apart from the acetylated samples, all treated samples tended to have large creep deformation in water-organic mixtures. For the acetylated samples, the creep deformation was small, except in case of acetone. These differences in the creep deformation behavior are mainly due to the differences in the glass-transition temperature of lignin as a result of the interaction between the wood constituents and the swelling liquid. The considerable increase in creep deformation due to hemicellulose-extraction suggests that hemicellulose, which interacts with lignin and cellulose, reduces the fluidity of the wood due to liquid desorption during creep measurements.

Confinement induced frustration in a one-dimensional lattice gauge theory

Coupling dynamical charges to gauge fields can result in highly non-local interactions with a linear confining potential. As a consequence, individual particles bind into mesons which, in one dimension, become the new constituents of emergent Luttinger liquids (LLs). Furthermore, at commensurate fillings, different Mott-insulating states can be stabilized by including nearest-neighbour (NN) interactions among charges. However, rich phase diagrams expected in such models have not been fully explored and still lack comprehensive theoretical explanation. Here, by combining numerical and analytical tools, we study a simple one-dimensional lattice gauge theory at half-filling, where U(1) matter is coupled to gauge fields and interacts through NN repulsion. We uncover a rich phase diagram where the local NN interaction stabilizes a Mott state of individual charges (or partons) on the one hand, and an LL of confined mesons on the other. Furthermore, at the interface between these two phases, we uncover a highly frustrated regime arising due to the competition between the local NN repulsion and the non-local confining interactions, realizing a pre-formed parton plasma. Our work is motivated by the recent progress in ultracold atom experiments, where such simple model could be readily implemented. For this reason we calculate the static structure factor which we propose as a simple probe to explore the phase diagram in an experimental setup.

Effects of sawdust and adhesive type on the properties of rice husk particleboards

This study set out to investigate the effects of adhesive type, rice husk and sawdust proportions on the properties of composite particleboards. Specimens of 200 × 200 × 24 mm were made by blending 500 g of rice husks with each adhesive type at a mass ratio of 1:1. The rest of the specimens of similar dimensions were prepared with addition of sawdust in the range of 10–40 wt%, while maintaining the ratio of biomass particles to adhesive at 1:1. Three commercial synthetic adhesives Fevicol (FV), Ponal (PA) and woodfix (WF) were used. The particle-adhesive mixtures were molded into a mat which was subsequently cold pressed at 10 MPa and left to dry in air. Density, water absorption (WA), linear expansion (LE), thickness swelling (TS), modulus of elasticity (MOE), modulus of rupture (MOR) and screw holding capacity of the specimens were evaluated. Adhesives were found to have over 42% solid content, with similar liquid constituents but in varying proportions. FTIR library search for the spectra of FV, PA and WF revealed correlations of 82.5%, 78.6% and 50.2%, respectively with polyvinyl-acetate. The developed boards had density 510–610 kg/m3, MOE 13–26 MPa, TS 9–31%, LE 3–7%. These properties suit them for furniture boards and sound proofing. The properties improved with increasing proportion of sawdust. FV and PA-bonded particleboards exhibited higher stability and strengths than WF-bonded particleboards due to higher concentrations of polyvinyl-acetate in the latter. Blending 40 wt% sawdust, 10 wt% rice husk with 50 wt% of either FV or PA showed better prospects.

Incorporation of liquid phase into solid particle packing model for precise design of low water/binder cement-based composites (LW/B-CC): Modelling and experiments

This paper addresses a novel method for the precise mixture design of low water/binder cement-based composites (LW/B-CC) by incorporating the liquid phase into a solid particle packing model. To achieve this goal, a typical LW/B-CC material, ultra-high performance concrete (UHPC), is used to clarify and verify this design method. More exactly, an optimized mixture of UHPC can be obtained by the following steps: Firstly, the water film thickness (WFT) is implanted into the modified Anderson and Andreasen model to obtain the optimized solid constituents proportions; then, a WFT predicted model based on D-optimal design approach is built; finally, proportions of liquid constituents (superplasticizer (SP) and water) are determined by the solution of simultaneous equations. To demonstrate the superior performance of the newly designed UHPC, its micro-meso-macro properties are evaluated in detail. The experimental results reveal that except water, the addition of SP can also significantly increase the WFT in UHPC. Moreover, the newly designed UHPC has advanced pore structure in all micro, meso and macro scales, where the total porosity is 7.07%, thereby contributing to excellent compressive strength (134.2 MPa). Additionally, some new insights are proposed to understand the development of LW/B-CC microstructure and strength by combining centroplasm effect, water film theory and particle packing theory. Overall, this research highlights the feasibility on optimized design of LW/B-CC incorporating the liquid constituents, which could further perfect the fundamental design theory of LW/B-CC materials.

Low-cost gel polymeric electrolytes for electrochromic applications

Solid-state ionic conductors embodying either protons or lithium ions are very attractive for large-area electrochromic (EC) devices. In this work, aiming at the preparation of a gel polymer electrolyte (GPE), two cheaper and non-toxic commercial resins are used: a urethane-based prepolymer (NOA65) and a vinyl acetate-based resin (MASTIFLEX). They are employed as host matrices to trap the liquid constituents, made of lithium perchlorate-propylene carbonate (LiClO 4 -PC). Thermogravimetric analyses indicate that both resins show excellent thermal performance. Several GPE formulations are investigated with respect to electrical and optical properties, varying the polymer-to-liquid ratio and LiClO 4 concentration. The EC devices made with the two GPEs are also characterized in terms of optical contrast, switching kinetics and repetitive switching cycles. These activities made it possible to find the best formulations finally employed for the fabrication of 100 cm 2 large area EC devices. The obtained results demonstrate that low-cost GPEs based on commercial polymers are electrochemically stable as ion-conducting media for EC devices. • Two low cost polymeric resins have been used as gel polymer electrolytes for the fabrication of electrochromic devices. • Optimization of electrolytes formulation in order to maximize the ionic conductivity. • Fabrication of a 100 cm 2 large area electrochromic device.

Developmental Effects of Electronic Cigarette Use.

Electronic cigarettes have gained widespread acceptance among adolescents and young adults. As a result of this popularity, there are concerns regarding the potential harm of primary, secondhand and thirdhand electronic cigarette exposures on fetal and postnatal development. In vitro studies have shown that constituents in electronic cigarette liquids, including nicotine, flavorings, and carrier agents can alter cellular processes and growth. Additionally, aerosolized electronic cigarette emissions have been shown to disrupt organ development and immune responses in preclinical studies. In clinical studies, an association between electronic cigarette use and frequent respiratory symptoms, greater asthma severity and impaired mucociliary clearance has been demonstrated with adolescent and young adult users of electronic cigarettes having twice the frequency of cough, mucus production, or bronchitis compared to nonusers. Along with the popularity of electronic cigarette use, secondhand electronic cigarette exposure has increased substantially; with almost one-fourth of middle and high school children reporting exposure to secondhand vapors. The health consequences of secondhand electronic cigarette exposure on children and other vulnerable populations are poorly understood but detectable levels of cotinine have been measured in nonusers. Pregnant women and their offspring are another vulnerable group at increased risk for health consequences from electronic cigarette exposure. Nicotine crosses the placenta and can disrupt brain and lung development in preclinical studies. This article will focus on the physiological and health effects associated with primary or secondhand exposure to electronic cigarettes. It is expected that with ongoing availability of electronic cigarettes as well as the accumulation of additional follow-up time for long-term outcomes, the risks associated with exposure will become better clarified. © 2022 American Physiological Society. Compr Physiol 12:3337-3346, 2022.

Appraisal of dispersion damping functions for the effective fragment potential method

The effective fragment potential (EFP) is a polarizable force field whose physically-motivated functional form is parameterized in an automated way from ab initio calculations, and whose dispersion potential has been suggested as a correction for Hartree-Fock or density functional theory calculations. However, the parameter-free dispersion damping potentials that are currently used in EFP do not follow from a rigorous derivation and do not satisfy simple limits for the dispersion energy. We introduce several new damping expressions that correct these deficiencies, then evaluate their performance alongside existing damping functions using a new database of ionic liquid constituents. This data set, which we call IL195×8, consists of complete-basis coupled-cluster interaction energies for 195 ion pairs at each of 8 different intermolecular separations. Ultimately, we recommend a new parameter-free dispersion damping function as a replacement for the one that is currently used in EFP.