On the Error Resilience of Ordered Binary Decision Diagrams

Ordered Binary Decision Diagrams (OBDDs) are a data structure that is used in an increasing number of fields of Computer Science (e.g., logic synthesis, program verification, data mining, bioinformatics, and data protection) for representing and manipulating discrete structures and Boolean functions. The purpose of this paper is to study the error resilience of OBDDs and to design a resilient version of this data structure, i.e., a self-repairing OBDD. In particular, we describe some strategies that make reduced ordered OBDDs resilient to errors in the indexes, that are associated to the input variables, or in the pointers (i.e., OBDD edges) of the nodes. These strategies exploit the inherent redundancy of the data structure, as well as the redundancy introduced by its efficient implementations. The solutions we propose allow the exact restoring of the original OBDD and are suitable to be applied to classical software packages for the manipulation of OBDDs currently in use. Another result of the paper is the definition of a new canonical OBDD model, called {\em Index-resilient Reduced OBDD}, which guarantees that a node with a faulty index has a reconstruction cost $O(k)$, where $k$ is the number of nodes with corrupted index

Application of Mechanically Fluidized Reactors to Lignin Pyrolysis

Lignin has great potential for the production of aromatics currently derived from petroleum, since it is the most abundant source of aromatics in nature. At present, Kraft lignin is used as fuel within the pulping process but, alternatively, it could be converted to high-value chemicals using thermochemical processes such as pyrolysis. Kraft lignin, however, is a very cohesive and thermally sensitive powder with foaming and agglomerating tendency under reaction conditions. Therefore, new reactor designs are necessary to efficiently process this raw material. Consequently, a novel reactor design, designated as Mechanically Fluidized Reactor (MFR) has been developed to successfully process Kraft lignin. To select the optimal stirrer geometry for fast pyrolysis of biomass, its mixing characteristics have been investigated with a technique developed to monitor the aeration resulting from the formation of gases and vapours during pyrolysis. The performance of different stirrers has been compared in terms of time for complete pyrolysis and the best performance, i.e. shortest time, was achieved with a design incorporating a vertical blades stirrer. The mixing provided by this type of stirrer was also simulated by Discrete Element Method model. In this work, Kraft lignin has been successfully pyrolyzed in the MFR. However, during the reaction, the bed material becomes cohesive and it is not possible to observe the bed aeration generated by the pyrolysis gas and vapours. Different bed materials were tested with the purpose of improving the Kraft lignin behaviour. All the materials capable of improving the processability, resulted in a watery bio-oil, most likely due to the catalytic enhancement of cracking reactions. Kraft lignin was also mixed with birch wood in different proportions. The liquid yield decreased linearly with Kraft lignin content in the initial feed, whereas phenolic compounds in the liquid product were found to increase linearly with increasing Kraft lignin content. The liquid product was analyzed in terms of alkyl phenols, guaiacols, catechols and syringols by GCxGC-TOFMS. Hydrolysis lignin residues from bioethanol production were much easier to pyrolyze, as the bed material did not become cohesive. The high ash content of these feedstocks, when compared to Kraft lignin, reduced the liquid yield

Fundamental study and applications to biomass pyrolysis of the mechanically fluidized reactor

Lignin has great potential for the production of aromatics currently derived from petroleum, since it is the most abundant source of aromatics in nature. At present, Kraft lignin is used as fuel within the pulping process but, alternatively, it could be converted to high-value chemicals using thermochemical processes such as pyrolysis. Kraft lignin, however, is a very cohesive and thermally sensitive powder with foaming and agglomerating tendency under reaction conditions. Consequently, a novel reactor design, designated as Mechanically Fluidized Reactor (MFR) has been developed to successfully process Kraft lignin. Please click Additional Files below to see the full abstract

DEM simulation of wood pellets dynamics in a mechanically fluidized reactor

The Mechanically Fluidized Reactor (MFR) is a novel technology developed to perform fast pyrolysis of solid biomass with particle size between 4 to 8 mm (1). The MFR has been developed to treat cohesive and thermally sensitive biomass materials. This technology does not require any fluidization gas, therefore the residence time of the vapors is solely controlled by their production rate. In order to get better process understanding and to optimize the process, the particle dynamics in the MFR has been numerically investigated in this contribution. The cylindrical apparatus with a stirrer consisting of vertical blades has been modeled (Fig. 1a). The simulations have been performed in the in-house developed simulation framework MUSEN (2), which is based on the Discrete Element Method (DEM). All particles in the apparatus (foamed glass beads and wood pellets) have been considered individually and for all particles the Newtonian equations of motion have been solved (Fig. 1b). Please click Additional Files below to see the full abstract

A computational study of the mechanism of the unimolecular elimination of α, β - unsaturated aldehydes in the gas phase

The 13th International Electronic Conference on Synthetic Organic Chemistry session Computational Chemistr

Case report: Pragmatic impairment in multiple sclerosis after worsening of clinical symptoms

Pragmatics, defined as the ability to integrate language and context to communicate effectively, may be impaired in Multiple Sclerosis (MS). We present the case of a patient with active secondary progressive MS who, after a first neuropsychological assessment that evidenced only a slight pragmatic impairment, suffered a sudden worsening of her clinical conditions, treated with corticosteroids. After this clinical worsening, her pragmatic abilities declined markedly, both in comprehension and production. This worsening was accompanied by a decline only in one attention task, in the context of an overall stable cognitive functioning. We conclude that pragmatics may be a domain particularly susceptible to cognitive worsening, highlighting the importance of its assessment in clinical practice

Farmed fish welfare during slaughter in Italy: survey on stunning and killing methods and indicators of unconsciousness

Information on slaughter procedures for farmed fish in aquaculture is limited, both in Europe and in Italy, due to a general lack of field data. The aim of this study was to gather information on the procedures used to slaughter fish in Italy and to discuss them considering the WOAH and EFSA recommendations on fish welfare. Using a questionnaire survey, data were collected by official veterinarians in 64 slaughtering facilities where 20 different species of fish were slaughtered. The main species slaughtered were rainbow trout (Oncorhynchus mykiss; 29/64), followed by European sea bass (Dicentrarchus labrax; 21/64), sea bream (Sparus aurata; 21/64), Arctic char (Salvelinus alpinus; 14/64), European eel (Anguilla anguilla; 11/64), sturgeon (Acipenser spp; 11/64), common carp (Cyprinus carpio; 6/64), and brown trout (Salmo trutta fario L.; 5/64). The most applied stunning/killing methods were “asphyxia in ice/thermal shock” and “electric in water bath,” followed by “percussion,” “asphyxia in air,” and “electric dry system.” After the application of the method, the assessment of the fish level of unconsciousness was practiced in 72% of the facilities using more than one indicator, with “breathing” and “coordinated movements” the most practiced. The collected data showed a discrepancy between the available recommendations about the welfare of fish at slaughter and what is practiced in many production sites, but for many species precise recommendations are still not available

Uso la plataforma H5P de creación de contenido interactivo como herramienta para la creación de un laboratorio de bioquímica virtual e interactivo

En este proyecto de innovación docente está diseñado para que el alumnado se acerque a un laboratorio de bioquímica virtual e interactivo y conozca los diferentes métodos y técnicas experimentales que se utilizan en ciertos análisis clínicos