61 research outputs found

    Bacterial-foraging optimization algorithm for non-hazardous plant layouts

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    PresentationThe following article approaches a safe plant layout design problem based on a bacterial-foraging optimization algorithm. Our approach finds the position in the two dimensional plane for each main process unit and evaluates the possibility of secondary contention for pertinent units, in order to minimize capital costs associated to equipment loss, piping, secondary contention, and usage of area. Fire and Explosion hazard is considered as the relevant safety aspect for distribution, and it is assessed through Dow’s Fire and Explosion Index. The proposed solution approach provides an alternative to hard-optimization methods, by allowing greater flexibility in accounting for both safety and economic aspects, while providing high quality solutions in a limited computation time. The aim of our proposed solution approach is to provide support to expert decision-making during the early plant layout design steps. A case study based on an acrylic-acid production plant, which has been used by several other papers that appeared in the literature, serves the purposes of showing the appropriateness and effectiveness of the method

    Métodos discretos basados en quimiotaxis de bacterias y algoritmos genéticos para solucionar el problema de la distribución de planta en celdas de manufactura.

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    This paper presents the mono-objective and multi-objective solution to the cell manufacturing layout problem using two new discrete hybrid algorithms based on bacterial chemotaxis and genetic algorithms. The proposed models simultaneously solve the issues that constitute the problem of the layout of manufacturing cells: the formation of the cells and the inter- and intra-cell layout, considering the clustering of cells, and the cost of transportation and material handling. The performance of the proposals was evaluated with benchmark problems of manufacturing cells, traveling salesman problem and a multi-objective version of knapsack problem. The mono-objective results were compared with GA, BFOA and Bacterial-GA, while the multi-objective results were compared with well-known algorithms NSGA2 and SPEA2, obtaining better performances in both cases.Este trabajo presenta la solución mono-objetivo y multi-objetivo del problema de la distribución de planta en celdas de manufactura a través de dos nuevos algoritmos híbridos discretos basados en quimiotaxis de bacterias y en algoritmos genéticos. Los modelos propuestos resuelven simultáneamente los dos inconvenientes que constituyen el problema de la distribución de planta en celdas de manufactura: la formación de las celdas y la distribución de planta intra e inter celdas, considerando el agrupamiento de las celdas y el costo de transporte y manipulación de materiales. El desempeño de las propuestas se evaluó con problemas de prueba de distribución de planta de celdas de manufactura, agente viajero (TSP) y el caso multi-objetivo del problema de las mochilas. Los resultados mono-objetivo se compararon con AG, BFOA y Bacterial-GA, mientras que los resultados multi-objetivo se compararon con los reconocidos algoritmos NSGA2 y SPEA2 en los que se obtuvo un mejor desempeño en los dos casos

    Integrated Electronics for Molecular Biosensing

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    This thesis, Integrated electronics for molecular biosensing, focuses on different approaches to sense the presence and activity of a specific analyte by using integrated electronic platforms. The aim of the first platform is to detect the enzyme telomerase. Telomerase causes the elongation of telomeres, which are part of the chromosomes, and determines the lifespan of cells. Telomerase expression is a marker of malignity in tumoral cells and its evaluation can be exploited for early diagnosis of many types of cancer cells. To detect the telomerase enzyme, a CMOS (complementary metal-oxide semiconductor) biosensor based on CMFET (Charge-Modulated Field Effect Transistor) able to measure kinetics of DNA replication and telomerase reaction was developed. The sensor can be functionalized by immobilizing single strands of DNA that contain the telomeric sequence, used as probes. If telomerase is present, the probes will be elongated by the enzyme and the charge on the sensing area will change, which reflects in a variation of the output current or voltage. The chip includes three different readout schemes (voltage, current- and time-based), each of which has different measuring ranges and operating conditions. The measured data is then digitized, stored, and can be sent off-chip through SPI (Serial Peripheral Interface) protocol. A total of 1024 biosensors have been integrated in a single chip with a size of 10x10 mm2. Each sensor can be independently addressed and functionalized by an electrochemical procedure using an integrated potentiostat, thus requiring no external equipment. Although the sensors have been tailored and optimized to perform telomerase detection, the sensing areas can be functionalized to be used with different analytes. This feature turns the chip into a complete bioassay platform. The second part of this work rises from the idea that bacteria, like Escherichia coli, can detect analytes in solution even at extremely low concentrations and change their movement through a process called chemotaxis, to move towards chemical gradients in the solution. E. coli moves by rotating its flagella either clockwise (for random tumbles) or counterclockwise (for straight runs, when it senses a chemical it is attracted to). Therefore, observing bacteria flagellar rotation can give enough information on the presence of a specific analyte in the solution. To electronically detect bacteria movement, an active surface covered in electrodes has been designed. By measuring the impedance between each pair of electrodes through an integrated LIA (lock-in amplifier), it is possible to know how a single bacterium is moving. By that, the presence or absence of the analyte can be deduced, thus effectively turning bacteria into chemical sensors

    A Review of Platforms for the Development of Agent Systems

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    Agent-based computing is an active field of research with the goal of building autonomous software of hardware entities. This task is often facilitated by the use of dedicated, specialized frameworks. For almost thirty years, many such agent platforms have been developed. Meanwhile, some of them have been abandoned, others continue their development and new platforms are released. This paper presents a up-to-date review of the existing agent platforms and also a historical perspective of this domain. It aims to serve as a reference point for people interested in developing agent systems. This work details the main characteristics of the included agent platforms, together with links to specific projects where they have been used. It distinguishes between the active platforms and those no longer under development or with unclear status. It also classifies the agent platforms as general purpose ones, free or commercial, and specialized ones, which can be used for particular types of applications.Comment: 40 pages, 2 figures, 9 tables, 83 reference

    Opinions and Outlooks on Morphological Computation

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    Morphological Computation is based on the observation that biological systems seem to carry out relevant computations with their morphology (physical body) in order to successfully interact with their environments. This can be observed in a whole range of systems and at many different scales. It has been studied in animals – e.g., while running, the functionality of coping with impact and slight unevenness in the ground is "delivered" by the shape of the legs and the damped elasticity of the muscle-tendon system – and plants, but it has also been observed at the cellular and even at the molecular level – as seen, for example, in spontaneous self-assembly. The concept of morphological computation has served as an inspirational resource to build bio-inspired robots, design novel approaches for support systems in health care, implement computation with natural systems, but also in art and architecture. As a consequence, the field is highly interdisciplinary, which is also nicely reflected in the wide range of authors that are featured in this e-book. We have contributions from robotics, mechanical engineering, health, architecture, biology, philosophy, and others

    Industrial lab-on-a-chip: design, applications and scale-up for drug discovery and delivery

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    Microfluidics is an emerging and promising interdisciplinary technology which offers powerful platforms for precise production of novel functional materials (e.g., emulsion droplets, microcapsules, and nanoparticles as drug delivery vehicles- and drug molecules) as well as high-throughput analyses (e.g., bioassays, detection, and diagnostics). In particular, multiphase microfluidics is a rapidly growing technology and has beneficial applications in various fields including biomedicals, chemicals, and foods. In this review, we first describe the fundamentals and latest developments in multiphase microfluidics for producing biocompatible materials that are precisely controlled in size, shape, internal morphology and composition. We next describe some microfluidic applications that synthesize drug molecules, handle biological substances and biological units, and imitate biological organs. We also highlight and discuss design, applications and scale up of droplet- and flow-based microfluidic devices used for drug discovery and delivery. © 2013 Elsevier B.V. All rights reserved

    Biofabricated Constructs of Carbon-based Nanoparticles with Mesenchymal Stem Cells for Orthopedic Repair

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    Breakthroughs in tissue engineering are moving at a rapid rate especially in the regenerative bone biofabrication. Technology growth in the field of additive manufacturing (AM) such 3D bioprinting which provides the ability to create biocompatible 3D construct on which a cell source could be seeded is an encouraging substitute to autologous grafts. This present research aims to biofabricate a construct for bone tissue engineering using AM technology. The biocompatible material was chosen corresponding to bones extracellular matrix (ECM) composition, which demonstrates an inorganic and organic development phase: Poly (lactic-glycolic acid) was chosen as the polymeric matrix of the compound, due to its bioactivity, biocompatibility, and ability to regulate biodegradability to support cell and bone function; graphene-nanoparticle was chosen for mechanical and organic reinforcement to support the mineral phase of the ECM. A commercial 3D bioprinter called the Aether 1 was used. The printer is a pneumatic based printer, which allows printing from hydrogels to thermo polymers. The bioprinter is located in the Regenerative Medicine Lab in the Large Animal Clinical Sciences. The first part of our study was to show the relationship of mesenchymal stem cells and graphene-nanoparticles. This was to evaluate the ECM layout on the graphene for biocompatibility and establish markers for supporting osteogenesis. Second part of the research dealt with finding a safe solvent to melt the different molar ratios of PLGA and the blending in of graphene-nanoparticles for low thermodynamic and low-pressure printing. This work dealt with the characterization, constating in the evaluation of different extrusion speeds, pressure values and nozzle diameters to construct a 3D print for testing the biocompatibility and cellular behavior. The final study was to utilize the 3D constructs in a long bone segmental defect model to characterize its in vivo capabilities. This work proved that the biofabrication of the PLGA+graphene blend could be achieved and repeatable with 3D bioprinting, supports cellular behavior for regeneration and provided results in the long bone defect study

    Opinions and Outlooks on Morphological Computation

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