Semicontinuous copolymerization of 80/20 wt % [2‐(acryloyloxy)ethyl]trimethyl ammonium chloride/acrylamide in an inverse microemulsion at high comonomer concentrations

The semicontinuous inverse microemulsion copolymerization of 80/20 wt % [2‐(acryloyloxy)ethyl]trimethylammonium chloride/acrylamide in an isoparaffin solvent at high comonomer concentrations (30–42 wt %) was studied with a mixture of nonionic surfactants (Crill 43 and Softanol 90) as the emulsifier and sodium metabisulfite as the initiator. The influence of the total comonomer concentration (TCC), emulsifier concentration (EC), hydrophilic–lipophilic balance (HLB), isopropyl alcohol (chain‐transfer agent) concentration (IPC), and crosslinking agent concentration (CAC) on the weight‐average molar mass (M_w), absolute viscosity (BV), and viscometric structuring index (VSI) of the obtained copolymers was analyzed. M_w and BV increased with TCC and HLB and decreased with EC. At the higher TCC, M_w decreased with IPC; meanwhile, at the lower TCC, M_w increased with IPC above 0.5 wt %. VSI increased with TCC, HLB, and IPC and decreased with EC. VSI increased dramatically with CAC, whereas BV showed a peak at the CAC of 10 ppm. In the absence of both chain‐transfer and crosslinking agents, M_w increased linearly with VSI, and this suggests that linear copolymers of very high M_w values cannot be obtained by inverse microemulsion copolymerization, at least for high TCCs. The results are explained in terms of both the collapsed state of the copolymer chains inside the latex particles and changes in the interface structure and composition. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Anti-SOD1 Nanobodies That Stabilize Misfolded SOD1 Proteins Also Promote Neurite Outgrowth in Mutant SOD1 Human Neurons

ALS-linked mutations induce aberrant conformations within the SOD1 protein that are thought to underlie the pathogenic mechanism of SOD1-mediated ALS. Although clinical trials are underway for gene silencing of SOD1, these approaches reduce both wild-type and mutated forms of SOD1. Here, we sought to develop anti-SOD1 nanobodies with selectivity for mutant and misfolded forms of human SOD1 over wild-type SOD1. Characterization of two anti-SOD1 nanobodies revealed that these biologics stabilize mutant SOD1 in vitro. Further, SOD1 expression levels were enhanced and the physiological subcellular localization of mutant SOD1 was restored upon co-expression of anti-SOD1 nanobodies in immortalized cells. In human motor neurons harboring the SOD1 A4V mutation, anti-SOD1 nanobody expression promoted neurite outgrowth, demonstrating a protective effect of anti-SOD1 nanobodies in otherwise unhealthy cells. In vitro assays revealed that an anti-SOD1 nanobody exhibited selectivity for human mutant SOD1 over endogenous murine SOD1, thus supporting the preclinical utility of anti-SOD1 nanobodies for testing in animal models of ALS. In sum, the anti-SOD1 nanobodies developed and presented herein represent viable biologics for further preclinical testing in human and mouse models of ALS.     

Adaptive sun tracking algorithm for incident energy maximization and efficiency improvement of PV panels

In recent times, sun tracking systems are being increasingly employed to enhance the efficiency of photovoltaic panels by constantly tracking the elevation and azimuth angles of the sun. In this paper, a novel adaptive digital signal processing and control algorithm is presented that optimizes the overall PV system output power by adjusting the position angles of the solar panel on both the elevation and azimuth axes. Since the proposed approach is adaptive in nature, the optimal position angles for the solar panel are iteratively computed using the adaptive gradient ascent method, until the incident solar radiation, and hence the output power is maximized. Furthermore, a Taylor’s series approximation is employed for generating a unique optimal position angle increment/decrement at each iteration. Simulation results show that the proposed technique demonstrates fast convergence and excellent tracking accuracy at all times of the day.     

Oxime-catalyzed formation of functionalized 1,3-oxathiolanes from aryl isothiocyanates and oxiranes

An efficient synthesis of N-(5-alkyl-1,3-oxathiolan-2-ylidene)arylamines via a one-pot reaction between arylisothiocyanates and substituted oxiranes in the presence of catalytic amount of pyridine-2-carbaldehyde oxime is described.     

Synthesis and Structural Characterization of G-SBA-IDA,G-SBA-EDTA and G-SBA-DTPA Modified Mesoporous SBA-15 Silica and Their Application for Removal of Toxic Metal Ions Pollutants

Silicon - Modified mesoporous SBA-15 silica materials (G-SBA-IDA, G-SBA-EDTA and G-SBA-DTPA) (where IDA, EDTA and DTPA represent iminodiacetic acid, ethylenediaminetetraacetic acid and...     

Electrochemistry of poly(vinylferrocene) modified electrodes in aqueous acidic media

A cyclic voltammetric study of the electrochemistry and chemical stability of the poly(vinylferrocene) (PVFc) redox couple, coated on a gold substrate, in aqueous solutions of H₂SO₄, HClO₄ and HCl was carried out. It was found that the anodic peak potential (E_pa) did not depend on the acid concentration in the range (1.0 × 10⁻² to 1.0 × 10⁻⁷ mol L⁻¹). However, the E_pa values shifted linearly to less positive potentials when investigated in more concentrated acid solutions in the range 1–5 mol L⁻¹. The slope of the E_pa versus acid concentration graph was found to be in the order H₂SO₄ > HCl > HClO₄. In this regard PVFc behaved very similar to 1,1′-bis(11-mercaptoundecyl)ferrocene (Fc(C₁₁SH)₂) except for its chemical stability. In H₂SO₄ media the PVFc was found to be much less stable than 1,1′-Fc(C₁₁SH)₂. The dependence of E_pa on acid concentration could be used to monitor state of charge of lead-acid batteries. However, for this application Fc(C₁₁SH)₂ would be a better choice because of its superior chemical stability.     

Hardware-In-the-Loop for on-line identification and control of three-phase squirrel cage induction motors

This paper describes a strategy for identification and control of three-phase squirrel cage induction motors. The strategy in this work is divided into 3 stages: on-line identification, off-line controller design, and on-line control. First, the transfer function is identified on-line. Next, the controller design is performed in a pure simulation environment using the identified transfer function. Finally, the designed controller is applied to the real system.Simulation and experimental results are presented to show the validity of the proposed strategy. Advantages of the proposed strategy include high accuracy in the identified system, simplicity, and low cost.     

Poly(ethylene oxide)‐based block copolymer electrolytes for lithium metal batteries

Nanostructured block copolymer electrolytes (BCEs) based on poly(ethylene oxide) (PEO) are considered as promising candidates for solid‐state electrolytes in high energy density lithium metal batteries (LMBs). Because of their self‐assembly properties, they confer on electrolytes both high mechanical strength and sufficient ionic conductivity, which linear PEO cannot provide. Two types of PEO‐based BCEs are commonly known. There are the traditional ones, also called dual‐ion conducting BCEs, which are a mixture of block copolymer chains and lithium salts. In these systems, the cations and anions participate in the conduction, inducing a concentration polarization in the electrolyte, thus leading to poor performances of LMBs. The second family of BCEs are single‐lithium‐ion conducting BCEs (SIC‐BCEs), which consist of anions being covalently grafted to the polymer backbone, therefore involving conduction by lithium ions only. SIC‐BCEs have marked advantages over dual‐ion conducting BCEs due to a high lithium ion transference number, absence of anion concentration gradients as well as low rate of lithium dendrite growth. This review focuses on the recent developments in BCEs for applications in LMBs with particular emphasis on the physicochemical and electrochemical properties of these materials. © 2018 Society of Chemical Industry     

Large electrocaloric effect in lead-free Ba1-xCaxTi1-yZryO3 ceramics under strong electric field at room-temperature

In this study, lead-free Ba_1-xCa_xZr_yTi_1-yO₃ (BCTZ(x, y)) ceramics were prepared by means of the classic solid-state reaction method. The morphotropic phase transition (MPB) from the orthorhombic to the tetragonal phase (O-T) was identified in this composition. Besides, the identification of those two structures at room temperature (RT) was made possible thanks to an X-ray diffraction (XRD) study. In order to determine the phase transitions dielectric measurements were conducted. Based on Maxwell equation, the electrocaloric (EC) effect in the studied ceramics was performed via the indirect method. The compositions gave maximum EC temperature changes (ΔT) at above their T_C on application of a 3?kV/mm electric field. These temperature changes are ΔT?=?0.565?K at T_EC=?392?K, ΔT?=?0.548?K at T_EC=?365?K and ΔT?=?0.235?K at T_EC=?307?K for BCZT(10%,5%), BCZT(13%,10%) and BCZT(20%,15%), respectively. At RT, these compositions provided a very interesting EC coefficient (ξ?=?ΔT/ΔE) compared to the pure BaTiO₃ (BT). These values, lying between 0.105 Kmm/kV and 0.188Kmm/kV for ΔE?=?3?kV/mm, are also greater than those related to some lead-based ferroelectric.     

Investigation of the physico‐mechanical properties of electrospun PVDF/cellulose (nano)fibers

The electro‐activity and mechanical properties of PVDF depends mainly on the β‐phase content and degree of crystallinity. In this study, cellulose fibers were used to improve these characteristics. This could be achieved because the hydroxyl groups on cellulose would force the fluorine atoms in PVDF to be in the trans‐conformation, and the cellulose particles could act as nucleation centers. Electrospinning was used to prepare the PVDF/cellulose (nano)fibrous films, and this improved the total crystallinity and the formation of β‐crystals. However, the presence and amount of cellulose in PVDF were found to have little influence on the β‐phase content and on the total crystallinity of PVDF. Improvements in the extent of crystallinity and the β‐phase content were primarily brought about by the chain‐ and crystal orientation as a result of electrospinning. The thermal stability of PVDF in the composites slightly increased with increasing cellulose content in the composites up to 1.0 wt %, while the modulus and tensile strength significantly increased up to the same filler level. The dielectric storage permittivity also increased with increasing cellulose content, but the presence of cellulose had no influence on the dynamics of the γ‐ and β‐relaxations of the PVDF. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43594.