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

Improvement of Co-Composting by a combined pretreatment Ozonation/Ultrasonic process in stabilization of raw activated sludge

The enhancement of composting technology to stabilize sludge pretreated by ozonation and ultrasonic was tested for 35 days. Secondary sludge produced by biological process are characterized with endogenous residue and inert solid matter which inhibit fully degrade bacterial cell walls. The composting process was performed with sludge pretreated with ozonatian and ultrasonics and green waste in a ratio of 2:1. The composting characteristics was evaluated for different physico-chemical and microbiological parameters in five different reactors. A high degree of composting quality was achieved with respect to significant reduction in volatile solids (VS) (32), total organic carbon (TOC) (35.0), C/N ratio (23.74), total coliform (TC) (168) along with the substantial increase in availability of nutrients like N (1.2) and P (8.77). High removal efficiency of TC and Fecal Coliform (FC) were observed in composting results, where simultaneous ultrasonic and ozonation were considered as primary-stabilization process. Therefore, applying integrated ultrasonic/ozonation with composting system for sludge stabilization is potentially useful technology in sustainable land restoration practices to meet standards and produce soil conditioner. © 2020, The Author(s)

Off-line approximate dynamic programming for the vehicle routing problem with a highly variable customer basis and stochastic demands

We study a stochastic variant of the vehicle routing problem (VRP) arising in the context of domestic donor collection services. The problem we consider combines the following attributes. Customers requesting services are variable, in the sense that they are stochastic, but are not restricted to a predefined set. Furthermore, demand volumes are also stochastic and are observed upon visiting customers. The objective is to maximize the expected served demands while meeting vehicle capacity and time restrictions. We call this problem the VRP with a highly Variable Customer basis and Stochastic Demands (VRP-VCSD). We first propose a classical Markov Decision Process (MDP) formulation for the VRP-VCSD. The resulting model is, however, unusable due to the explosion in the dimension of the state and action spaces.To solve the VRP-VCSD, we propose a number of methodological contributions aimed at reducing the state and action spaces. We first reformulate the MDP as an MDP with a consecutive action selection procedure. In this formulation, we enforce the treatment of a single vehicle (as opposed to multiple vehicles) at each decision epoch. We then introduce an observation function that selects a subset of the available information, which is deemed relevant for the considered vehicle in each epoch. We develop a Q-learning algorithm called QN-CO. In particular, we use a continuous state representation and incorporate a two-layer artificial neural network to approximate the Q values. Furthermore, we propose an aggregation strategy yielding a fixed-size output. Finally, we enhance our algorithm with Replay Memory and a Double Q Network.We conduct a thorough computational analysis. Results show that QN-CO considerably outperforms five benchmark policies. Moreover, we show that QN-CO can compete with specialized methods developed for the particular case of the VRP-VCSD where customer locations and expected demands are known in advance

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

Genetic and Epigenetic landscape of Germline Stem Cells

Elucidating the critical epigenetics events involved in differentiation and reprogramming of cells to primordial germ cells (PGCs) is among the interesting issues in stem cell research. Here, I will talk about critical transcription factors and global hypomethylation in development of germ cells. Evidence strongly suggests that the earliest PGCs emerging in the E7.25 mouse embryo epiblast have a highly methylated genome, and high level of H3K9me2 in chromatin but during development, genome demethylated and patterns of histone codes changes dramatically. We designed a polycistroniclentiviral vector and overexpressed Stella, Oct4 and Nanos2 simultaneously in transduced cells; Increasing level of Prdm14, Nanog and decreasing of G9a expression is an interesting finding which might be considered as a primary step of reprogramming toward germline progenitor cells, here we propose decreasing H3K9me2 level as a consequence of G9a down regulation is a critical step which facilitated transition to different stemness state through creating a new epigenetic memory for the early germ cells.   Keywords: Epigenetic, hypomethylation, Germ line Stem Cells, polycistroniclentiviral vector

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

Construction and Quantitative Evaluation of a Dual Specific Promoter System for Monitoring the Expression Status of Stra8 and c-kit Genes.

Applications of genetic constructs with multiple promoters, which are fused with reporter genes and simultaneous monitoring of various events in cells, have gained special attention in recent years. Lentiviral vectors, with their distinctive characteristics, have been considered to monitor the developmental changes of cells in vitro. In this study, we constructed a novel lentiviral vector (FUM-M), containing two germ cell-specific promoters (Stra8 and c-kit), fused with ZsGreen and DsRed2 reporter genes, and evaluated its efficiency in different cells following treatments with retinoic acid and DMSO. Several cell lines (P19, GC-1 spg and HEK293T) were transduced with this vector, and functional capabilities of the promoters were verified by flow cytometry and quantitative RT-PCR. Our results indicate that FUM-M shows dynamic behavior in the presence and absence of extrinsic factors. A correlation was also observed between the function of promoters, present in the lentiviral construct and the endogenous level of the Stra8 and c-kit mRNAs in the cells. In conclusion, we recommend this strategy, which needs further optimization of the constructs, as a beneficial and practical way to screen chemical inducers involved in cellular differentiation toward germ-like cells

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