Assessment of supercapacitive performance of europium tungstate nanoparticles prepared via hydrothermal method

Nano-sized europium tungstate particles were prepared by reacting europium nitrate hexahydrate and sodium tungstate solutions, and the structures, morphology and optical properties of the product were evaluated by XRD, FT-IR, SEM, and UV–Visible techniques. The Eu₂(WO₄)₃ nanoparticles were evaluated as potential materials for constructing supercapacitor electrodes using the results of cyclic voltammetry, galvanostatic charge/discharge (GCD) and electrochemical impedance spectroscopy and the electrodes were found to have a specific capacitance (SC) value of 347 F g^?1 in a 2.0 M H₂SO₄ electrolyte at a scan rate of 2 mV s^?1. The electrodes were further studied at the GCD at a current density of 1 A g^?1, and the SC of the building material was found to be 282 F g^?1. The cycling durability of the electrodes was also found to be excellent. After 4000 cycles the SC values of the electrodes were found to reach 129%. The preparation method and the resulting nano-particles, were hence found to be promising for high performance energy applications.     

Microfluidic Synthesis of Ultrasmall Chitosan/Graphene Quantum Dots Particles for Intranasal Delivery in Alzheimer's Disease Treatment

Nanoparticles (NPs) based therapies for Alzheimer's disease (AD) attract interest due to their ability to pass across or bypass the blood-brain barrier. Chitosan (CS) NPs or graphene quantum dots (GQDs) are promising drug carriers with excellent physicochemical and electrical properties. The current study proposes the combination of CS and GQDs in ultrasmall NP form not as drug carriers but as theranostic agents for AD. The microfluidic-based synthesis of the CS/GQD NPs with optimized characteristics makes them ideal for transcellular transfer and brain targeting after intranasal (IN) delivery. The NPs have the ability to enter the cytoplasm of C6 glioma cells in vitro and show dose and time-dependent effects on the viability of the cells. IN administration of the NPs to streptozotocin (STZ) induced AD-like models lead to a significant number of entrances of the treated rats to the target arm in the radial arm water maze (RAWM) test. It shows the positive effect of the NPs on the memory recovery of the treated rats. The NPs are detectable in the brain via in vivo bioimaging due to GQDs as diagnostic markers. The noncytotoxic NPs localize in the myelinated axons of hippocampal neurons. They do not affect the clearance of amyloid β (Aβ) plaques at intercellular space. Moreover, they showed no positive impact on the enhancement of MAP2 and NeuN expression as markers of neural regeneration. The memory improvement in treated AD rats may be due to neuroprotection via the anti-inflammation effect and regulation of the brain tissue microenvironment that needs to be studied.     

Quantum discord protection of a two-qutrit V-type atomic system from decoherence by partially collapsing measurements

In this paper, by exploiting the weak measurement and quantum measurement reversal procedure, we propose a scheme to show how one can protect the geometric quantum discord (GQD) of a two-qutrit V-type atomic system each of which interacts with a dissipative reservoir independently. We examine the scheme for the GQD of the initial two-qutrit Werner and Horodecki states for different classes of weak measurement strengths. It is found out that the presented protocol enables us to suppress decoherence due to the amplitude damping channel and preserve the quantum discord of the two-qutrit system successfully.     

Requirement of system–reservoir bound states for entanglement protection

In this work, a genuine mechanism for entanglement protection of a two- qubit system interacting with a dissipative common reservoir is investigated. Based on generating a bound state for the system–reservoir, we show that stronger bound state in the energy spectrum can be created by adding another non-interacting qubits into the reservoir. It turns out that obtaining higher degrees of boundedness in the energy spectrum leads to a better protection of two-qubit entanglement against the dissipative noises. Also, it is figured out that the formation of bound state not only exclusively determines the long-time entanglement protection, irrespective to the Markovian and non-Markovian dynamics, but also performs the same task for reservoirs with different spectral densities.     

Inferential closed‐loop control of particle size and molecular weight distribution in emulsion polymerization of styrene

In this work, simultaneous inferential control of particle size distribution (PSD) and molecular weight distribution (MWD) in a semi‐batch emulsion polymerization reactor of styrene has been addressed. Using a comprehensive dynamic model for PSD and MWD predictions and performing a sensitivity analysis, it has been revealed that free surfactant and chain transfer agent (CTA) concentrations in the reactor are the most suitable candidates for inferential control of PSD and MWD, respectively. To control concentrations of these species in the reactor, their inlet feed flow rates are used as manipulated variables. It is assumed that the concentration of CTA is measured infrequently and therefore an open‐looped observer, based on the reaction calorimetry, has been designed to estimate the CTA concentration. The infrequent measurements of CTA concentration are used to correct its estimation. As the online measuring of the ionic free surfactant concentration is also difficult, solution conductivity which is a good indication of free surfactant concentration is used for control purposes. Simulation results show that the performance of the proposed control scheme is satisfactory even in the presence of model mismatch. POLYM. ENG. SCI., 2010. © 2010 Society of Plastics Engineers     

Sodium status and the metabolic syndrome: A systematic review and meta-analysis of observational studies

The prevalence of metabolic syndrome (MetS) has been greatly increased, worldwide. In recent years, investigators have proposed that sodium might contribute to the development of metabolic syndrome; however, the published data were conflicting. The present systematic review aimed to summarize the evidence from observational studies in this regard. We conducted a systematic search for relevant observational studies investigating the association between sodium status and MetS, published until June 2017 in electronic databases including PubMed, EMBASE, Scopus and Google Scholar. Summary effects were derived using random effects model. After screening the records, seventeen publications with 66,274 participants were eligible to be included in the systematic review and meta-analysis. The analysis revealed that subjects with MetS have significantly higher levels of sodium compared to healthy controls (Hedges' g = 0.21, 95% CI: 0.12, 0.29, I² = 68.6). Subgroup analyses revealed that the difference was significant when the sodium status was assessed using urinary sodium levels. The random effects meta-regression analysis also revealed that body sodium level increases with the number of MetS components. Furthermore, participants with highest dietary/urinary or serum sodium levels had 37% higher chance of developing MetS when compared with participants with the lowest sodium levels (OR = 1.37 95%CI: 1.31, 1.42, I² = 86.9). The current meta-analysis revealed that higher sodium input into the body is directly associated with the likelihood of MetS. Prospective cohort studies and well-designed randomized clinical trials considering the effect of sodium restricted diets on the risk of MetS as an outcome are necessary to represent the causal association.     

Evaluation of the performance of heat pump-assisted distillation of an ethanol–water mixture

The process of separation of an ethanol–water mixture was simulated. A heat pump system was then implemented on the distillation column with the highest energy requirements in the process. Complete elimination of hot and cold utilities of the pretreatment column was obtained through an improved system by application of a heat pump at a compressor work of 406.6 kW. Installation of the heat pump system on the pretreatment column of the system results in a reduction of 10.7% of annual operating costs and 6.6% of the total annual costs (TAC). However, the capital costs of the process will enhance by 22.6%.     

A higher-order micro-beam model with application to free vibration

The free vibration of micro-beams is analyzed employing three different beam models. The previously obtained equations of motion for Bernoulli–Euler and Timoshenko models are solved analytically. A higher-order model is devised, which satisfies the lateral boundary conditions of micro-beams. The equations of motion with associated boundary conditions are derived by means of Hamilton's principle. The generalized differential quadrature method is used for the solution of the equations. The first five natural frequencies are obtained for micro-beams with three length-scale parameter/height ratios and five different boundary conditions.