Resolution of rotational ambiguity for three-component systems

Soft modeling of multivariate data is a powerful method for the analysis of processes that cannot be described quantitatively by a chemical model. Soft modeling usually does not result in unique solutions. Thus, the determination of the range of feasible solutions is important. For two-component systems the determination of that range is well-understood; for three-component systems the task is remarkably more complex. We present a novel method that can be applied to any multivariate data set, irrespective of overlap or realistic noise level. The expansion to four components is indicated.     

Influence of ionic liquid concentration on the electromechanical performance of ionic electroactive polymer actuators

We have investigated influence of ionic liquid concentration on the electromechanical response of ionic electroactive polymer actuators. Actuators were fabricated from ionomeric membrane and doped with different concentrations of 1-ethyl-3-methylimidazolium trifluoromethanesulfonate ionic liquid. Samples were investigated for their electromechanical and electrochemical characteristics; and it was observed that the maximum electromechanical strain of approximately 1.4% is achieved at 22 wt% ionic liquid content. Increasing ionic liquid concentration results in saturation of the electrode–ionomer interface and formation of ionic double/multi layers, which in turn result an inward accumulation of ions; hence, generate strain in an undesired direction that deteriorates the electromechanical response of the actuator.     

Perceived indoor air quality in naturally ventilated primary schools in the UK: Impact of environmental variables and thermal sensation

Indoor air quality (IAQ) in classrooms has a significant impact on children's academic performance, health, and well-being; therefore, understanding children's perception of IAQ is vital. This study investigates how children's perception of IAQ is affected by environmental variables and thermal sensation. In total, 29 naturally ventilated classrooms in eight UK primary schools were selected and 805 children were surveyed during non-heating and heating seasons. Results show that air sensation votes (ASVs) are more correlated to CO₂ levels than to operative temperatures (T_op) during non-heating seasons and more correlated to T_op than CO₂ levels during heating seasons. The impact of T_op on ASVs decreases with an increase in CO₂ levels, and the effect of CO₂ levels on ASVs decreases with increase in T_op. The most favorable ASVs are given when children feel “cool” and have “as it is” preference. By keeping CO₂ < 1000 ppm and T_op within children's thermal comfort band, ASVs are improved by 43%. The study recommends that standards should consider the impact of both temperature and CO₂ levels on perceived IAQ. Perception of IAQ also affects children's overall comfort and tiredness levels; however, this influence is more significant on tiredness level than that on overall comfort level.     

Distinguished discriminatory separation of CO2 from its methane-containing gas mixture via PEBAX mixed matrix membrane

Highly selective separation of CO2 from its methane-containing binary gas mixture can be achieved by using Poly(ether-block-amide) (PEBAX) mixed matrix membranes (MMMs).According to FESEM and AFM analyses,silica-based nanoparticles were homogenously integrated within the polymer matrix,facilitating penetration of CO2 through the membrane while acting as barrier for methane gas.The membrane containing 4.6 wt％ fumed silica (FS) (PEBAX/4.6 wt％ FS) exhibits astonishing selectivity results where binary gas mixture of CO2/CH4 was used as feed gas.As detected by gas chromatography,in the permeate side,data showed a significant increase of CO2 permeance,while CH4 transport through the mixed matrix membrane was not detectable.Moreover,PEBAX/4.6 wt％ FS greatly exceeds the Robeson limit.According to data reported on CO2/CH4 gas pair separation in the literature,the results achieved in this work are beyond those data reported in the literature,particularly when PEBAX/4.6 wt％ FS membrane was utilized.     

Fabrication of a highly selective and sensitive Gd(III)-PVC membrane sensor based on N-(2-pyridyl)-N′-(4-nitrophenyl)thiourea

In this work we report the development of a highly selective and sensitive Gd(III) membrane based on N-(2-pyridyl)-N′-(4-nitrophenyl)thiourea (PyTu4NO₂) as an excellent neutral ion carrier. The Gd(III) sensor exhibits a Nernstian slope of 19.95 ± 0.3 mV per decade over the concentration range of 3.0 × 10⁻⁷ to 1.0 × 10⁻¹ M, and a detection limit of 3.0 × 10⁻⁷ M of Gd(III) ions. The potentiometric response of the sensor is independent of the solution pH in the range of 4.0–9.0. It manifests advantages of low detection limit, fast response time (10 s), and most significantly, very good selectivity with respect to a number of lanthanide ions (La, Ce, Sm, and Eu ions). It can be used at least for a period of 8 weeks without any significant divergences in its potential response. To assess its analytical applicability the proposed Gd(III) sensor was successfully applied as an indicator electrode in the titration of Gd(III) ion solutions with EDTA and for the determination of the fluoride ion in two mouth wash preparations. It was also used for the direct monitoring of Gd(III) ions in binary mixtures.     

Engineering a drug eluting ocular patch for delivery and sustained release of anti-inflammatory therapeutics

Ocular inflammation is commonly associated with eye disease or injury. Effective and sustained ocular delivery of therapeutics remains a challenge due to the eye physiology and structural barriers. Herein, we engineered a photocrosslinkable adhesive patch (GelPatch) incorporated with micelles (MCs) loaded with loteprednol etabonate (LE) for delivery and sustained release of drug. The engineered drug loaded adhesive hydrogel, with controlled physical properties, provided a matrix with high adhesion to the ocular surfaces. The incorporation of MCs within the GelPatch enabled solubilization of LE and its sustained release within 15 days. In vitro studies showed that MC loaded GelPatch supported cell viability and growth. In addition, subcutaneous implantation of the MC loaded GelPatch in rats confirmed its in vivo biocompatibility and stability within 28 days. This non-invasive, adhesive, and biocompatible drug eluting patch can be used as a matrix for the delivery and sustained release of hydrophobic drugs.     

A mechanistic study of the fire performance of the silica and zinc borate nanoparticles-incorporated intumescent coatings based on epoxy resin

An epoxy-based intumescent coating containing the silica and zinc borate nanoparticles was fabricated. The fire performance of the coating with the optimum formulation was investigated in terms of the changes in the physical and chemical structure of the formed char layer during the exposure to a temperature of 1000°C. The state of the chemical structure was analyzed by performing the Fourier-transform infrared spectroscopy, x-ray diffraction, and x-ray photoelectron spectroscopy analysis from the char layer at the three-time intervals of 10, 30, and 60 min of the heating process. The innovative Condorcet method was also employed to examine the changes in the physical structure of the formed char layer. Some instabilities were detected in the physical structure of the char layer in the middle period of heating. Moreover, a gradual formation of silicon carbide crystalline structure was observed on top of the surface, followed by its oxidation to silica over time. In contrast, in the bulk structure, silicon crystalline structures (Coesite) intensified with time. Boron nitride was also increasingly created on the top surface and in the bulk of the coating over the heating time. These findings proved the effective role of the silica and zinc-borate nanoparticles in the fire performance of epoxy-based intumescent coatings.