Simulation Analysis of A Propane Recovery Plant from Using ASPEN PLUS

Natural gas is a good source of various hydrocarbon compounds, but, alkanes with three or more number of carbon atoms in there chain are of greater value as fuels as well as pure components. A cryogenic plant is setup to recover propane, butane, and other heavier alkanes with two operating distillation columns; de-methanizer and de-ethanizer. The available software Aspen Plus is used to simulate this cryogenic plant to serve the purpose of recovery .This software facilitates us to infer the impact of the operating variables on the efficiency of the plant. The use of cryogenic plants for this purpose is a latest project carried on just by a few companies, so the idea here is to analyse the operating variables to optimize the recover

Neurofibromatosis

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Biobased Latexes from Natural Oil Derivatives

International audienceVinyl monomers from eugenol (EBM) and guaiacol (GBM) were copolymerized in miniemulsion process with high oleic soybean oil-based (HOSBM) counterpart to yield latexes with higher biobased content. Fully renewable monomer feed yields a broad range of new emulsion polymers with the number-average molecular weight varying at 25,000-650,000 g/mol. Increasing GBM/EBM content in the reactive feed leads to increasing latex molecular weight due to the decreasing unsaturation degree (lower content of HOSBM). Monomer feed unsaturation effect found to be more pronounced for latexes from EBM and HOSBM, since GBM shows higher reactivity in free radical polymerization if compared to GBM. Presence of oil-derived unsaturated fragments in emulsion polymers provides an opportunity to crosslink latexes in a controlled way and adjust the resulting polymer networks mechanical properties. Biobased latexes from 25-90 wt.% of GBM/EBM and 10-75 wt.% of HOSBM were synthesized, characterized and tested in terms of thermomechanical properties of latex crosslinked films and coatings. It is demonstrated that characteristics of latex films and coatings are determined by nature and ratio of aliphatic oil residues of HOSBM and aromatic fragments of EBM/GBM in the macromolecular backbone. Incorporation of rigid fragments of GBM/EBM enhances Young's modulus of the films, whereas the soft plant oil-based units contribute to flexibility of films and coatings. All crosslinked latex films exhibited decent properties and performance in terms of hardness, impact resistance, as well as adhesion to the steel substrate. By combination of aliphatic fatty acid fragments of HOSBM with aromatic GBM/EBM structure, durable latexes can be synthesized with ability to balance thermomechanical properties of the latex polymer networks in a broad range

Potential neuroprotective role of astroglial exosomes against smoking-induced oxidative stress and HIV-1 replication in the central nervous system

Introduction: HIV-1-infected smokers are at risk of oxidative damage to neuronal cells in the central nervous system by both HIV-1 and cigarette smoke. Since neurons have a weak antioxidant defense system, they mostly depend on glial cells, particularly astrocytes, for protection against oxidative damage and neurotoxicity. Astrocytes augment the neuronal antioxidant system by supplying cysteine-containing products for glutathione synthesis, antioxidant enzymes such as SOD and catalase, glucose for antioxidant regeneration via the pentose-phosphate pathway, and by recycling of ascorbic acid. Areas covered: The transport of antioxidants and energy substrates from astrocytes to neurons could possibly occur via extracellular nanovesicles called exosomes. This review highlights the neuroprotective potential of exosomes derived from astrocytes against smoking-induced oxidative stress, HIV-1 replication, and subsequent neurotoxicity observed in HIV-1-positive smokers. Expert opinion: During stress conditions, the antioxidants released from astrocytes either via extracellular fluid or exosomes to neurons may not be sufficient to provide neuroprotection. Therefore, we put forward a novel strategy to combat oxidative stress in the central nervous system, using synthetically developed exosomes loaded with antioxidants such as glutathione and the anti-aging protein Klotho