Investigation of the anticorrosion performance of lignin coatings after crosslinking with triethyl phosphate and their adhesion to a polyurethane topcoat

This study investigates the anticorrosion properties of sustainable organic coatings, which were prepared by dissolution of two different types of technical lignins - organosolv lignin (OL) and kraft lignin (KL) - in an organic solvent and applied onto iron-phosphated steel by airassisted spray coating. Influence of triethyl phosphate (TEP) as a crosslinking agent for lignin and its effect on the anticorrosion properties of coatings during 24 h of immersion in 3.5% NaCl were investigated. Results obtained from electrochemical impedance spectroscopy (EIS) of coated steels suggest that the initial protection performance (1 h immersion) of non-crosslinked OL is higher than that of KL. Nevertheless, KL coatings that contained TEP and were heat-treated at elevated temperature (180 °C) demonstrated the best overall anticorrosion performance. In contrast, a similar trend was not observed for OL coatings, which indicates that the structural properties of lignin may be a crucial factor in applicability of TEP as a crosslinking agent. In addition, a layer of polyurethane was applied on all the different types of lignin coatings prepared and their adhesion characteristics were studied by crosscut adhesion measurements (ISO 2409). These adhesion results revealed that neither KL-TEP nor OL-TEP coatings demonstrate proper adhesive characteristics with a polyurethane (PU) topcoat and consequently these coatings are not suitable for utilization as a primer coating for the PU topcoat studied

Statistical analysis of E-jet print parameter effects on Ag-nanoparticle ink droplet size

In this paper, we have studied the print parameter effects on electrohydrodynamic inkjet (E-jet) resolution using statistical analysis. In order to make the E-jet manufacturing process feasible, the effect of printing parameters on the ejected droplet size must be modelled and optimized. To this end, there exist two approaches: parameter effects can be modelled using theoretical calculations or they can be generated directly from empirical data using statistical analysis. The first option has been explored by multiple research groups, whereas the latter has received less interest. In this article, the effect of printing parameters on the width of AC-pulsed E-jet deposited Ag-nanoparticle ink droplets are investigated using design of experiments (DoE) approach and statistical analysis. As a result, a statistical model for deposited droplet width is generated using four print parameters (print height, bias voltage, peak voltage and frequency) as predictors. The model can predict 94.24% of the measured width variation with a standard deviation of 1.05 μm.acceptedVersionPeer reviewe

The Efficiency of Compost and Vermicompost Reactors for Stabilizing Organic Waste and Municipal Sewage Sludge

BACKGROUND AND OBJECTIVE: Unsystematic waste and sewage sludge disposal is a major public health threat. Today, the use of easy, inexpensive, and natural treatment such as compost is one of the main priorities for the treatment of these materials. METHODS: In this experimental study, organic waste samples were prepared from household waste and sludge samples were prepared from municipal sewage treatment plant. Reactors R1 and R2 (for compost and vermicompost, waste), and R3 and R4 (for compost and vermicompost, waste and sewage sludge mixtures) were selected. Waste and sludge stabilization were evaluated by some indexes such as: (C/N), (VS), (TOC) and (TC), (FC) and (TP) and (TN). FINDINGS: The level of VS in R1, R2, R3 and R4 decreased from 89.09, 89.09, 85.29 and 85.29 to 75.58, 64.04, 62.75 and 61.22, respectively. C/N values in R1, R2, R3 and R4 reached 28.08, 22.48, 21.31, and 18.60 during the process. Fecal coliforms in R2, R3 and R4 decreased by 100, 93 and 99%, respectively. The vermicompost quality in R2 and R4 reactors was better than other reactors, but the R4 reactor reached this condition one week earlier. CONCLUSION: According to the results of this study, vermicompost reactor containing organic waste and sewage sludge is well-prepared for the high rate stage of composting process. In order to achieve optimal composting conditions in accordance with valid standards, the composting stage should be included in the work plans

Suppression of dsRNA response genes and innate immunity following Oct4, Stella, and Nanos2 overexpression in mouse embryonic fibroblasts

International audienceThe self-renewal capacity of germline derived stem cells (GSCs) makes them an ideal source for research and use in clinics. Despite the presence of active gene network similarities between embryonic stem cells (ESCs) and GSCs, there are unanswered questions regarding the roles of evolutionary conserved genes in GSCs. To determine the reprogramming potential of germ cell- specific genes, we designed a polycistronic gene cassette expressing Stella, Oct4 and Nanos2 in a lentiviral-based vector. Deep transcriptome analysis showed the activation of a set of pluripotency and germ-cell-specific markers and the downregulation of innate immune system. The global shut down of antiviral genes included MHC class I, interferon response genes and dsRNA 2′-5′-oligoadenylate synthetase are critical pathways that has been affected. Individual expression of each factor highlighted suppressive effect of Nanos2 on genes such as Isg15 and Oasl2. Collectively, to our knowledge this is the first report showing that Nanos2 could be considered as an immunosuppressive factor. Furthermore, our results demonstrate suppression of endogenous retrotransposons that harbor immune response but further analysis require to uncover the correlation between transposon suppression and immune response in germ cell development. © 2018 Elsevier Lt

Architectural modifications for flexible supercapacitor performance optimization

We have developed material and architectural alternatives for flexible supercapacitors and investigated their effect on practical performance. The substrate alternatives include paperboard as well as various polyethylene terephthalate (PET) films and laminates, with aqueous NaCl electrolyte used in all devices. In all the supercapacitors, activated carbon is used as the active layer and graphite ink as the current collector, with various aluminium or copper structures applied to enhance the current collectors’ conductivity. The capacitance of the supercapacitors was between 0.05 F and 0.58 F and their equivalent series resistance (ESR) was from <1 Ω to 14 Ω, depending mainly on the current collector structure. Furthermore, leakage current and self- discharge rates were defined and compared for the various architectures. The barrier properties of the supercapacitor encapsulation have a clear correlation with leakage current, as was clearly shown by the lower leakage in devices with an aluminium barrier layer. A cycle life test showed that after 40000 charge-discharge cycles the capacitance decreases by less than 10%