Browsing by Keyword "Applied Mathematics"
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Item Compact and cost effective instrument for detecting drug precursors in different environments based on fluorescence polarization(SPIE-INT SOC OPTICAL ENGINEERING, 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA, 2013) Antolín-Urbaneja, Juan Carlos; Eguizabal, I.; Briz, N.; Dominguez, A.; Estensoro, Patxi; Secchi, A.; Varriale, A.; Di Giovanni, S.; D´Auria, S.; Tecnalia Research & Innovation; ROBOTICA_AUTOMA; TECNOLOGÍAS DE HIDRÓGENO; SG; MAQUINAS; GENERALSeveral techniques for detecting chemical drug precursors have been developed in the last decade. Most of them are able to identify molecules at very low concentration under lab conditions. Other commercial devices are able to detect a fixed number and type of target substances based on a single detection technique providing an absence of flexibility with respect to target compounds. The construction of compact and easy to use detection systems providing screening for a large number of compounds being able to discriminate them with low false alarm rate and high probability of detection is still an open concern. Under CUSTOM project, funded by the European Commission within the FP7, a stand-alone portable sensing device based on multiple techniques is being developed. One of these techniques is based on the LED induced fluorescence polarization to detect Ephedrine and Benzyl Methyl Keton (BMK) as a first approach. This technique is highly selective with respect to the target compounds due to the generation of properly engineered fluorescent proteins which are able to bind the target analytes, as it happens in an “immune-type reaction”. This paper deals with the advances in the design, construction and validation of the LED induced fluorescence sensor to detect BMK analytes. This sensor includes an analysis module based on high performance LED and PMT detector, a fluidic system to dose suitable quantities of reagents and some printed circuit boards, all of them fixed in a small structure (167mm x 193mm x 228mm) with the capability of working as a stand-alone application.Item Development of a resistivity standard for polymeric materials used in photovoltaic modules(SPIE, 2015) Kempe, Michael D.; Miller, David C.; Nobles, Dylan L.; Sakurai, Keiichiro; Tucker, John; Bokria, Jayesh G.; Shioda, Tsuyoshi; Nanjundiah, Kumar; Yoshihara, Toshio; Birchmier, Jeff; Zubillaga, Oihana; Wohlgemuth, John H.; Dhere, Neelkanth G.; Jones-Albertus, Rebecca; Wohlgemuth, John H.; SISTEMAS FOTOVOLTAICOSPhotovoltaic (PV) modules, operate at high voltages and elevated temperatures, and are known to degrade because of leakage current to ground. Related degradation processes may include: electric/ionic corrosion, electrochemical deposition, electromigration, and/or charge build-up in thin layers. The use of polymeric materials with a high resistivity is known to reduce the rate of potential induced degradation processes. Because of this, PV materials suppliers are placing increased importance on the encapsulant bulk resistivity, but there is no universally accepted method for making this measurement. The development of a resistivity test standard is described in this paper. We have performed a number of exploratory and round-robin tests to establish a representative and reproducible method for determining the bulk resistivity of polymeric materials, including encapsulation, backsheet, edge seals, and adhesives. The duration of measurement has been shown to greatly affect the results, e.g., an increase as great as 100X was seen for different measurement times. The standard has been developed using measurements alternating between an on and off voltage state with a weighted averaging function and cycle times of an hour.Item Feasibility of Storing Latent Heat with Liquid Crystals. Proof of Concept at Lab Scale(2016-05) Bayon, Rocio; Coco, Silverio; Barcenilla, Maria; Espinet, Pablo; Imbuluzqueta, Gorka; Hidalgo, Jokin; Rojas, Esther; SISTEMAS FOTOVOLTAICOS; VALORIZACIÓN DE RESIDUOSIn this work, the first experimental results of thermotropic liquid crystals used as phase change materials for thermal storage are presented. For that purpose, the n = 10 derivative from the family of 4-n-alkoxybiphenyl-4-carboxylic acids has been prepared. Different techniques like polarized-light microscopy, differential scanning calorimetry, thermogravimetric analysis and rheological measurements have been applied for its characterization. Having a mesophase/isotropic transition temperature around 251 degrees C, a clearing enthalpy of 55 kJ/kg, a thermal heat capacity of around 2.4 kJ/kg and a dynamic viscosity lower than 0.6 Pas, this compound fulfills the main requirements for being considered as latent heat storage material. Although further studies on thermal stability are necessary, the results already obtained are both promising and encouraging since they demonstrate de viability of this new application of liquid crystals as thermal storage media.Item In-situ steel solidification imaging in continuous casting using magnetic induction tomography(2020-03-12) Soleimani, Manuchehr; Li, F; Spagnul, S; Palacios, J; Barbero, J; Gutierrez, T; Viotto, A; Centros PRE-FUSION TECNALIA - (FORMER); PROMETAL; CIRMETAL: Solidification process in continuous casting is a critical part of steel production. The speed and quality of the solidification process determines the quality of final product. Computational fluid dynamics (CFD) simulations are often used to describe the process and design of its control system, but so far, there is no any tool that provides an on-line measurement of the solidification front of hot steel during the continuous casting process. This paper presents a new tool based on magnetic induction tomography (MIT) for real time monitoring of this process. The new MIT system was installed at the end of the secondary cooling chamber of a casting unit and tested during several days in a real production process. MIT is able to create an internal map of electrical conductivity of hot steel deep inside the billet. The image of electrical conductivity is then converted to temperature profile that allows the measurement of the solid, mushy and liquid layers. In this study, such a conversion is done by synchronizing in one time step the MIT measurement and the thermal map generated with the actual process parameters available at that time. The MIT results were then compared with the results obtained of the CFD and thermal modelling of the industrial process. This is the first in-situ monitoring of the interior structure during a real continuous casting.Item Laser hybrid joining of plastic and metal components for lightweight components(SPIE-INT SOC OPTICAL ENGINEERING, 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA, 2015) Rauschenberger, J.; Cenigaonaindia, A.; Keseberg, J.; Vogler, D.; Gubler, U.; Liébana, F.; Dorsch, Friedhelm; COMPOSITEPlastic-metal hybrids are replacing all-metal structures in the automotive, aerospace and other industries at an accelerated rate. The trend towards lightweight construction increasingly demands the usage of polymer components in drive trains, car bodies, gaskets and other applications. However, laser joining of polymers to metals presents significantly greater challenges compared with standard welding processes. We present recent advances in laser hybrid joining processes. Firstly, several metal pre-structuring methods, including selective laser melting (SLM) are characterized and their ability to provide undercut structures in the metal assessed. Secondly, process parameter ranges for hybrid joining of a number of metals (steel, stainless steel, etc) and polymers (MABS, PA6.6-GF35, PC, PP) are given. Both transmission and direct laser joining processes are presented. Optical heads and clamping devices specifically tailored to the hybrid joining process are introduced. Extensive lap-shear test results are shown that demonstrate that joint strengths exceeding the base material strength (cohesive failure) can be reached with metal-polymer joining. Weathering test series prove that such joints are able to withstand environmental influences typical in targeted fields of application. The obtained results pave the way toward implementing metal-polymer joints in manufacturing processes.Item On Nonlinear Model Predictive Control for Energy-Efficient Torque-Vectoring(2021-01) Parra, Alberto; Tavernini, Davide; Gruber, Patrick; Sorniotti, Aldo; Zubizarreta, Asier; Perez, Joshue; Tecnalia Research & Innovation; CCAMA recently growing literature discusses the topics of direct yaw moment control based on model predictive control (MPC), and energy-efficient torque-vectoring (TV) for electric vehicles with multiple powertrains. To reduce energy consumption, the available TV studies focus on the control allocation layer, which calculates the individual wheel torque levels to generate the total reference longitudinal force and direct yaw moment, specified by higher level algorithms to provide the desired longitudinal and lateral vehicle dynamics. In fact, with a system of redundant actuators, the vehicle-level objectives can be achieved by distributing the individual control actions to minimize an optimality criterion, e.g., based on the reduction of different power loss contributions. However, preliminary simulation and experimental studies – not using MPC – show that further important energy savings are possible through the appropriate design of the reference yaw rate. This paper presents a nonlinear model predictive control (NMPC) implementation for energy-efficient TV, which is based on the concurrent optimization of the reference yaw rate and wheel torque allocation. The NMPC cost function weights are varied through a fuzzy logic algorithm to adaptively prioritize vehicle dynamics or energy efficiency, depending on the driving conditions. The results show that the adaptive NMPC configuration allows stable cornering performance with lower energy consumption than a benchmarking fuzzy logic TV controller using an energy-efficient control allocation layer.Item A random-key encoded harmony search approach for energy-efficient production scheduling with shared resources(2015-11-02) Garcia-Santiago, C.A.; Del Ser, Javier; Upton, C.; Quilligan, F.; Gil-Lopez, S.; Salcedo-Sanz, Sancho; IAWhen seeking near-optimal solutions for complex scheduling problems, meta-heuristics demonstrate good performance with affordable computational effort. This has resulted in a gravitation towards these approaches when researching industrial use-cases such as energy-efficient production planning. However, much of the previous research makes assumptions about softer constraints that affect planning strategies and about how human planners interact with the algorithm in a live production environment. This article describes a job-shop problem that focuses on minimizing energy consumption across a production facility of shared resources. The application scenario is based on real facilities made available by the Irish Center for Manufacturing Research. The formulated problem is tackled via harmony search heuristics with random keys encoding. Simulation results are compared to a genetic algorithm, a simulated annealing approach and a first-come-first-served scheduling. The superior performance obtained by the proposed scheduler paves the way towards its practical implementation over industrial production chains.