4,532 research outputs found

    Process Calculi Abstractions for Biology

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    Several approaches have been proposed to model biological systems by means of the formal techniques and tools available in computer science. To mention just a few of them, some representations are inspired by Petri Nets theory, and some other by stochastic processes. A most recent approach consists in interpreting the living entities as terms of process calculi where the behavior of the represented systems can be inferred by applying syntax-driven rules. A comprehensive picture of the state of the art of the process calculi approach to biological modeling is still missing. This paper goes in the direction of providing such a picture by presenting a comparative survey of the process calculi that have been used and proposed to describe the behavior of living entities. This is the preliminary version of a paper that was published in Algorithmic Bioprocesses. The original publication is available at http://www.springer.com/computer/foundations/book/978-3-540-88868-

    Brane Calculi Systems: A Static Preview of their Possible Behaviour

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    We improve the precision of a previous Control Flow Analysis for Brane Calculi, by adding information on the context and introducing causality information on the membranes. This allows us to prove some biological properties on the behaviour of systems specified in Brane Calculi.Comment: Presented at MeCBIC 201

    Vibration Briquetting of Ash of Combined Heat and Power Plant

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    Ash and slag materials of combined heat and power plant (CHPP) are a unique resource that can be successfully used in construction, road and agricultural industries. However, their industrial use is accompanied with significant organizational and technical problems. Granulation of coal ashes improves the conditions of their storage and transportation, allows mechanizing and automating the subsequent use, increases productivity, improves the working conditions and reduces the loss of raw materials and finished products. This paper proposes a method of compacting of Seversk CHPP (Russia) ash by vibration briquetting using a number of binders (polyvinyl alcohol, glyoxal, liquid sodium glass). The main characteristics of Seversk CHPP ash such as chemical composition, particle size distribution, bulk density, content of unburnt carbon and radioactivity have been determined. Investigation of the effect of binder concentration on the static strength of granules revealed that the increase of binder concentration results in the growth of static strength of the dried granules that reaches a maximum at the concentration of 10 wt %: 0.28 MPa for polyvinyl alcohol, 0.63 MPa for glyoxal and 0.40 MPa for liquid sodium glass

    Vibration Briquetting of Ash of Combined Heat and Power Plant

    Get PDF
    Ash and slag materials of combined heat and power plant (CHPP) are a unique resource that can be successfully used in construction, road and agricultural industries. However, their industrial use is accompanied with significant organizational and technical problems. Granulation of coal ashes improves the conditions of their storage and transportation, allows mechanizing and automating the subsequent use, increases productivity, improves the working conditions and reduces the loss of raw materials and finished products. This paper proposes a method of compacting of Seversk CHPP (Russia) ash by vibration briquetting using a number of binders (polyvinyl alcohol, glyoxal, liquid sodium glass). The main characteristics of Seversk CHPP ash such as chemical composition, particle size distribution, bulk density, content of unburnt carbon and radioactivity have been determined. Investigation of the effect of binder concentration on the static strength of granules revealed that the increase of binder concentration results in the growth of static strength of the dried granules that reaches a maximum at the concentration of 10 wt %: 0.28 MPa for polyvinyl alcohol, 0.63 MPa for glyoxal and 0.40 MPa for liquid sodium glass

    An albumin-derived peptide scaffold capable of binding and catalysis

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    We have identified a 101-amino-acid polypeptide derived from the sequence surrounding the IIA binding site of human albumin. The polypeptide contains residues that make contact with ligands as warfarin in the parent protein, and eight cysteine residues to form disulfide bridges, which stabilize the polypeptide structure. Seventy-four amino acids are located in six [alpha]-helical regions, with the remaining amino acids forming six connecting coil/loop regions. Codon usage optimization was used to express a GST fusion protein in E. coli in yields as high as 4 mg/l. This fusion protein retains its structural integrity and aldolase activity, the ability to direct the stereochemical outcome of a diketone reduction, and its binding capacity to warfarin and efavirenz. Notably, this newly cloned polypeptide represents a valuable starting point for the construction of libraries of binders and catalysts with improved proficiency

    Dynamic Dependency Pairs for Algebraic Functional Systems

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    We extend the higher-order termination method of dynamic dependency pairs to Algebraic Functional Systems (AFSs). In this setting, simply typed lambda-terms with algebraic reduction and separate {\beta}-steps are considered. For left-linear AFSs, the method is shown to be complete. For so-called local AFSs we define a variation of usable rules and an extension of argument filterings. All these techniques have been implemented in the higher-order termination tool WANDA

    A Comparative Review of Binder-Containing Extrusion and Alternative Shaping Techniques for Structuring of Zeolites into Different Geometrical Bodies

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    Zeolites are crystalline metallosilicates displaying unique physicochemical properties with widespread applications in catalysis, adsorption, and separation. They are generally obtained by a multi-step process that starts with primary mixture aging, followed by hydrothermal crystallization, washing, drying, and, finally, a calcination step. However, the zeolites obtained are in the powder form and because of generating a pressure drop in industrial fixed bed reactors, not applicable for industrial purposes. To overcome such drawbacks, zeolites are shaped into appropriate geometries and desired size (a few centimeters) using extrusion, where zeolite powders are mixed with binders (e.g., mineral clays or inorganic oxides). The presence of binders provides good mechanical strength against crushing in shaped zeolites, but binders may have adverse impacts on zeolite catalytic and sorption properties, such as active site dilution and pore blockage. The latter is more pronounced when the binder has a smaller particle size, which makes the zeolite internal active sites mainly inaccessible. In addition to the shaping requirements, a hierarchical structure with different levels of porosity (micro-, meso-, and macropores) and an interconnected network are essential to decrease the diffusion limitation inside the zeolite micropores as well as to increase the mass transfer because of the presence of larger auxiliary pores. Thus, the generation of hierarchical structure and its preservation during the shaping step is of great importance. The aim of this review is to provide a comprehensive survey and detailed overview on the binder-containing extrusion technique compared to alternative shaping technologies with improved mass transfer properties. An emphasis is allocated to those techniques that have been less discussed in detail in the literature.</p
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