Single‐chain polymer nanoparticles via click crosslinking and effect of photoinduced radical combination on crosslink points

Folding of azide functionalized polymer chains was obtained via the copper‐catalyzed azide alkyne cycloaddition (CuAAC) methodology using a light‐responsive crosslinker as the ‘click’ component. Subsequently, crosslinked junction points were combined with a photoinduced radical combination strategy to achieve more compact nanoparticles. The resultant folding particles possess smaller particle sizes and higher glass transition temperature values compared to their linear analogues. Fourier transform IR spectroscopy, SEC, DSC, dynamic light scattering, ¹H NMR and TEM techniques were used for characterization. © 2020 Society of Chemical Industry     

Optimization of multiple input–output fuzzy membership functions using clonal selection algorithm

A clonal selection algorithm (CLONALG) inspires from clonal selection principle used to explain the basic features of an adaptive immune response to an antigenic stimulus. It takes place in various scientific applications and it can be also used to determine the membership functions in a fuzzy system. The aim of the study is to adjust the shape of membership functions and a novice aspect of the study is to determine the membership functions. Proposed method has been implemented using a developed CLONALG program for a multiple input–output (MI–O) fuzzy system. In this study, GA and binary particle swarm optimization (BPSO) are used for implementing the proposed method as well and they are compared. It has been shown that using clonal selection algorithm is advantageous for finding optimum values of fuzzy membership functions     

4.2 V Stack of metal oxide-polypyrrole-based composite electrodes and their power management

Polypyrrole (PPy)-based composites containing nanostructured VO _x, PbO _x, and MnO _x are galvanostatically synthesized on exfoliated graphite papers (1.0 and 6.25 cm²) formed as a result of the intercalation with their metals. Both intercalation and synthesis are performed in the synthesis solution containing metal(II)tetrafluoroborate salts, pyrrole monomer, HBF₄, H₂O, Triton-X 100 (TX100), and carboxymethyl cellulose (CMC). The mass loading of the composite at the electrode is maintained at 10 mg cm⁻². Symmetric and asymmetric unit cells are prepared in polyvinyl alcohol (PVA)/H₂SO₄ (1:1) gel electrolyte using composites synthesized on the treated graphite paper electrode. The electrical properties of these cells are examined by electrochemical impedance spectroscopy and their capacitive properties by cyclic voltammetry and galvanostatic-charge discharge test. The asymmetrical cell, prepared with PPy/PbO _x/CMC composite having energy density and cycle life better than others, exhibits 7.77 Wh kg⁻¹ and 0.51 kW kg⁻¹ at a working voltage of 1.4 V, considering the total mass of all sub-components. The three-cell asymmetric stack design, which is prepared using these composite-coated electrodes, achieves a coulombic efficiency of 76% at 4.2 V. Finally, an electronic control system (DC/DC buck-boost converter) is designed and implemented to manage the charge and discharge cycles of single-cell and bipolarly connected stack to operate the asymmetric supercapacitor arrays with high performance.     

Open and closed tube method for determination of resonance frequencies of nanofibrous membrane

Nanofibrous layer performs as a membrane that vibrates at low frequencies. This property is obtained by nano dimensions of the interfiber areas. Sound waves incident on the acoustic resonance membrane make the membrane oscillate, and the maximum amplitude occurs in the case of resonance. The structures based on the nanofibrous layers are employed for low-frequency sound absorption. The resonance of the nanofibrous elements allows acoustic energy to be converted into thermal energy. In this article, a nanofibrous layer was produced by electrostatic spinning from an aqueous solution of polyvinyl alcohol and the resonance effect of nanofibrous layer was studied. For this purpose, the new method developed for determination of resonance frequencies of a membrane was employed. The ultimate objective of the study was to assess the effect of mass per unit area on resonance frequencies of the membrane placed in an open and closed tube. The results indicated that the resonance frequencies of the membrane decreased with an increase of the mass per unit area of the nanofibrous membrane. Except for the lowest frequencies (first resonance peak), the resonant behavior of the membrane was affected by the resonance of tube.     

Cylinder Pressure Prediction of An HCCI Engine Using Deep Learning

Engine tests are both costly and time consuming in developing a new internal combustion engine.Therefore,it is of great importance to predict engine characteristics with high accuracy using artificial intelligence.Thus,it is pos-sible to reduce engine testing costs and speed up the engine development process.Deep Learning is an effective artificial intelligence method that shows high performance in many research areas through its ability to learn high-level hidden features in data samples.The present paper describes a method to predict the cylinder pressure of a Homogeneous Charge Compression Ignition(HCCI)engine for various excess air coefficients by using Deep Neural Network,which is one of the Deep Learning methods and is based on the Artificial Neural Network(ANN).The Deep Learning results were compared with the ANN and experimental results.The results show that the difference between experimental and the Deep Neural Network(DNN)results were less than 1％.The best results were obtained by Deep Learning method.The cylinder pressure was predicted with a maximum accuracy of 97.83％ of the experimental value by using ANN.On the other hand,the accuracy value was increased up to 99.84％ using DNN.These results show that the DNN method can be used effectively to predict cylinder pressures of internal combustion engines.     

Anodic polymerization of 2,5-di-(2-thienyl)-furan in ethanol

Poly(2,5-di-(2-thienyl)-furan) (PSOS) was synthesized via anodic polymerization of 2,5-di-(2-thienyl)-furan (SOS) in ethanol solution containing 0.2 M LiClO₄ as supporting electrolyte. The electrochemical and spectroelectrochemical properties were investigated using electroanalytical and UV–vis spectroscopic techniques, respectively. The band gap of the polymer film was found as 2.22 eV and the film was successfully switched between black oxidized state and orange neutral state. Fluorescence and electrochemical impedance spectroscopy (EIS) studies were also performed.     

Synthesis of chitosan beads as boron sorbents

Parameters, such as pH, temperature, initial boron concentration, adsorbent dosage, and ionic strength, affecting boron adsorption onto chitosan beads were examined in this study. The following values were obtained as the optimum conditions in our studied ranges: pH 8.0, temperature = 308 K, amount of chitosan beads = 0.15 g, initial boron concentration = 4 mg L⁻¹, and ionic strength = 0.1 M NaCl]. The adsorption kinetics were also examined in terms of three kinetic models: the pseudo‐first‐order, pseudo‐second‐order, and intraparticle diffusion models. The pseudo‐second‐order kinetic model showed very good agreement with the experimental data. Intraparticle plots seemed to have two steps and indicated multilinearity. Equilibrium data were evaluated with nonlinear and linear forms of the Langmuir and Freundlich equations. The experimental data conformed to the Freundlich equation on the basis of the formation of multilayer adsorption. To characterize the synthesized chitosan beads, we used Fourier transform infrared (FTIR) spectroscopy and scanning electron microscopy (SEM) analyses. As shown by FTIR analysis, the boron species may have interacted with the NH₂ groups on chitosan. Microparticles of about 5 μm appeared in the SEM micrographs of the chitosan beads. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Of microparticles and bacteria identification--(resonance) Raman micro-spectroscopy as a tool for biofilm analysis

Confocal resonance Raman microscopy is a powerful tool for the non-invasive analysis of complex biological aggregates without preparation and prior knowledge of the samples. We present the capabilities of confocal resonance Raman microscopy with a spatial resolution of 350 nm² × 2.0 μm and excitation times of 1 s and less per recorded spectrum. Granules sampled from two sequencing batch reactors (SBR) for anaerobic ammonium oxidization (anammox) were regularly mapped in vivo for three months after SBR startup. Uncultured microorganisms and mineral particles were tracked throughout operation and identified in situ by their (resonance) Raman spectra. Co-existing microcolonies of Nitrosomonae formed the outer layer of anammox granules. Polymorph TiO₂ microparticles were found embedded in the outer layer of granules overgrown with purple bacteria, indicating bacterial response to the variant toxicity of the mineral phase.     

Osteogenic activities of polymeric soybean oil-g-polystyrene membranes

A novel biocompatible copolymer membrane was synthesized and characterized for use in guided bone regeneration using polymeric soybean oil-g-polystyrene (PSO-g-PS) graft copolymer which was successfully obtained by free radical polymerization of styrene initiated by PSO peroxide as a macroinitiator at 80 °C. Osteoblastic cellular activities of MC3T3-E1 cells on PSO-g-PS membranes with different soybean oil composition (PSO-g-PS1, PSO-g-PS2, and PSO-g-PS3) were evaluated. Nuclear magnetic resonance (¹H NMR) spectra showed that PSO inclusion (mol%) was found to be 27, 69, and 51 % for PSO-g-PS1, PSO-g-PS2, and PSO-g-PS3 membranes, respectively. Superior biocompatibility of the PSO-g-PS membranes was determined compared to polystyrene tissue culture plates (TCPS) as positive control. Cell proliferation was enhanced on PSO-g-PS2 and PSO-g-PS3 membranes compared to PSO-g-PS1 membranes (p < 0.001), and a statistically significant higher ALP value of MC3T3-E1 cells on PSO-g-PS2 membranes (p < 0.05) suggested that proliferation and differentiation of preosteoblastic on PSO-g-PS membranes were enhanced with regard to soybean oil content within the membranes. Thus, the present study suggests that PSO-g-PS2 membranes, which showed a favorable biological environment for the preosteoblastic cells, can be well suited for bone tissue engineering applications.     

Buttermilk as milk powder and whey substitute in compound milk chocolate: Comparative study and optimisation

The aim of this study was to investigate the optimal concentration of milk, whey and buttermilk powder by using mixture design for the formulation of compound milk chocolate. The influence of buttermilk as a milk and whey substitute on the main physicochemical parameters of compound milk chocolate was investigated. The optimisation of the variables indicated that using 35.660% milk powder, 27.957% whey powder and 36.383% buttermilk produced the optimum milk chocolate with the highest desirability without undesirable changes in the quality properties. Chocolates containing equal amounts of buttermilk and milk powder and also equal amounts of whey powder and buttermilk powder demonstrated high consumer acceptability.