30 resultados para Oil and gas application
em Universidad Politécnica de Madrid
Resumo:
The objective of this study was to evaluate the effects of increasing doses [0 (control: CON), 20, 60, 180 and 540 mg/L incubation medium] of garlic oil (GO) and cinnamaldehyde (CIN) on in vitro ruminal fermentation of two diets. Batch cultures of mixed ruminal microorganisms were inoculated with ruminal fluid from four sheep fed a medium-concentrate diet (MC; 50 : 50 alfalfa hay : concentrate) or four sheep fed a high-concentrate diet (HC; 15 : 85 barley straw : concentrate). Diets MC and HC were representative of those fed to dairy and fattening ruminants, respectively. Samples of each diet were used as incubation substrates for the corresponding inoculum, and the incubation was repeated on 4 different days (four replicates per experimental treatment). There were GO × diet-type and CIN × diet-type interactions (P < 0.001–0.05) for many of the parameters determined, indicating different effects of both oils depending on the diet type. In general, effects of GO were more pronounced for MC compared with HC diet. Supplementation of GO did not affect (P > 0.05) total volatile fatty acid (VFA) production at any dose. For MC diet, GO at 60, 180 and 540 mg/L decreased (P < 0.05) molar proportion of acetate (608, 569 and 547 mmol/mol total VFA, respectively), and increased (P < 0.05) propionate proportion (233, 256 and 268 mmol/mol total VFA, respectively), compared with CON values (629 and 215 mmol/mol total VFA for acetate and propionate, respectively). A minimum dose of 180 mg of GO/L was required to produce similar modifications in acetate and propionate proportions with HC diet, but no effects (P > 0.05) on butyrate proportion were detected. Methane/VFA ratio was reduced (P < 0.05) by GO at 60, 180 and 540 mg/L for MC diet (0.23, 0.16 and 0.10 mol/mol, respectively), and by GO at 20, 60, 180 and 540 mg/L for HC diet (0.19, 0.19, 0.16 and 0.08 mol/mol, respectively), compared with CON (0.26 and 0.21 mol/mol for MC and HC diets, respectively). No effects (P = 0.16–0.85) of GO on final pH and concentrations of NH3-N and lactate were detected. For both diet types, the highest CIN dose decreased (P < 0.05) production of total VFA, gas and methane, which would indicate an inhibition of fermentation. Compared with CON, CIN at 180 mg/L increased (P < 0.05) acetate proportion for the MC (629 and 644 mmol/mol total VFA for CON and CIN, respectively) and HC (525 and 540 mmol/mol total VFA, respectively) diets, without affecting the proportions of any other VFA or total VFA production. Whereas for MC diet CIN at 60 and 180 mg/L decreased (P < 0.05) NH3-N concentrations compared with CON, only a trend (P < 0.10) was observed for CIN at 180 mg/L with the HC diet. Supplementation of CIN up to 180 mg/L did not affect (P = 0.18–0.99) lactate concentrations and production of gas and methane for any diet. The results show that effectiveness of GO and CIN to modify ruminal fermentation may depend on diet type, which would have practical implications if they are confirmed in vivo.
Resumo:
In the current uncertain context that affects both the world economy and the energy sector, with the rapid increase in the prices of oil and gas and the very unstable political situation that affects some of the largest raw materials’ producers, there is a need for developing efficient and powerful quantitative tools that allow to model and forecast fossil fuel prices, CO2 emission allowances prices as well as electricity prices. This will improve decision making for all the agents involved in energy issues. Although there are papers focused on modelling fossil fuel prices, CO2 prices and electricity prices, the literature is scarce on attempts to consider all of them together. This paper focuses on both building a multivariate model for the aforementioned prices and comparing its results with those of univariate ones, in terms of prediction accuracy (univariate and multivariate models are compared for a large span of days, all in the first 4 months in 2011) as well as extracting common features in the volatilities of the prices of all these relevant magnitudes. The common features in volatility are extracted by means of a conditionally heteroskedastic dynamic factor model which allows to solve the curse of dimensionality problem that commonly arises when estimating multivariate GARCH models. Additionally, the common volatility factors obtained are useful for improving the forecasting intervals and have a nice economical interpretation. Besides, the results obtained and methodology proposed can be useful as a starting point for risk management or portfolio optimization under uncertainty in the current context of energy markets.
Resumo:
In this work, an analytical method was developed for the determination of pharmaceutical drugs inbiosolids. Samples were extracted with an acidic mixture of water and acetone (1:2, v/v) and supportedliquid extraction was used for the clean-up of extracts, eluting with ethyl acetate:methanol (90:10, v/v).The compounds were determined by gas chromatography?tandem mass spectrometry using matrix-match calibration after silylation to form their t-butyldimethylsilyl derivatives. This method presentsvarious advantages, such as a fairly simple operation for the analysis of complex matrices, the use ofinexpensive glassware and low solvent volumes. Satisfactory mean recoveries were obtained with thedeveloped method ranging from 70 to 120% with relative standard deviations (RSDs) ? 13%, and limitsof detection between 0.5 and 3.6 ng g?1. The method was then successfully applied to biosolids samplescollected in Madrid and Catalonia (Spain). Eleven of the sixteen target compounds were detected in thestudied samples, at levels up to 1.1 ?g g?1(salicylic acid). Ibuprofen, caffeine, paracetamol and fenofibratewere detected in all of the samples analyzed.
Resumo:
The Spanish National Library (Biblioteca Nacional de España1. BNE) and the Ontology Engineering Group2 of Universidad Politécnica de Madrid are working on the joint project ?Preliminary Study of Linked Data?, whose aim is to enrich the Web of Data with the BNE authority and bibliographic records. To this end, they are transforming the BNE information to RDF following the Linked Data principles3 proposed by Tim Berners Lee.
End-User Development Success Factors and their Application to Composite Web Development Environments
Resumo:
The Future Internet is expected to be composed of a mesh of interoperable Web services accessed from all over the Web. This approach has not yet caught on since global user-service interaction is still an open issue. Successful composite applications rely on heavyweight service orchestration technologies that raise the bar far above end-user skills. The weakness lies in the abstraction of the underlying service front-end architecture rather than the infrastructure technologies themselves. In our opinion, the best approach is to offer end-to-end composition from user interface to service invocation, as well as an understandable abstraction of both building blocks and a visual composition technique. In this paper we formalize our vision with regard to the next-generation front-end Web technology that will enable integrated access to services, contents and things in the Future Internet. We present a novel reference architecture designed to empower non-technical end users to create and share their own self-service composite applications. A tool implementing this architecture has been developed as part of the European FP7 FAST Project and EzWeb Project, allowing us to validate the rationale behind our approach.
Resumo:
We review the evolution, state of the art and future lines of research on the sources, transport pathways, and sinks of particulate trace elements in urban terrestrial environments to include the atmosphere, soils, and street and indoor dusts. Such studies reveal reductions in the emissions of some elements of historical concern such as Pb, with interest consequently focusing on other toxic trace elements such as As, Cd, Hg, Zn, and Cu. While establishment of levels of these elements is important in assessing the potential impacts of human society on the urban environment, it is also necessary to apply this knowledge in conjunction with information on the toxicity of those trace elements and the degree of exposure of human receptors to an assessment of whether such contamination represents a real risk to the city’s inhabitants and therefore how this risk can be addressed.
Resumo:
Program specialization optimizes programs for known valúes of the input. It is often the case that the set of possible input valúes is unknown, or this set is infinite. However, a form of specialization can still be performed in such cases by means of abstract interpretation, specialization then being with respect to abstract valúes (substitutions), rather than concrete ones. We study the múltiple specialization of logic programs based on abstract interpretation. This involves in principie, and based on information from global analysis, generating several versions of a program predicate for different uses of such predicate, optimizing these versions, and, finally, producing a new, "multiply specialized" program. While múltiple specialization has received theoretical attention, little previous evidence exists on its practicality. In this paper we report on the incorporation of múltiple specialization in a parallelizing compiler and quantify its effects. A novel approach to the design and implementation of the specialization system is proposed. The resulting implementation techniques result in identical specializations to those of the best previously proposed techniques but require little or no modification of some existing abstract interpreters. Our results show that, using the proposed techniques, the resulting "abstract múltiple specialization" is indeed a relevant technique in practice. In particular, in the parallelizing compiler application, a good number of run-time tests are eliminated and invariants extracted automatically from loops, resulting generally in lower overheads and in several cases in increased speedups.
Resumo:
The implementation of abstract machines involves complex decisions regarding, e.g., data representation, opcodes, or instruction specialization levéis, all of which affect the final performance of the emulator and the size of the bytecode programs in ways that are often difficult to foresee. Besides, studying alternatives by implementing abstract machine variants is a time-consuming and error-prone task because of the level of complexity and optimization of competitive implementations, which makes them generally difficult to understand, maintain, and modify. This also makes it hard to genérate specific implementations for particular purposes. To ameliorate those problems, we propose a systematic approach to the automatic generation of implementations of abstract machines. Different parts of their definition (e.g., the instruction set or the infernal data and bytecode representation) are kept sepárate and automatically assembled in the generation process. Alternative versions of the abstract machine are therefore easier to produce, and variants of their implementation can be created mechanically, with specific characteristics for a particular application if necessary. We illustrate the practicality of the approach by reporting on an implementation of a generator of production-quality WAMs which are specialized for executing a particular fixed (set of) program(s). The experimental results show that the approach is effective in reducing emulator size.
Resumo:
A number of data description languages initially designed as standards for trie WWW are currently being used to implement user interfaces to programs. This is done independently of whether such programs are executed in the same or a different host as trie one running the user interface itself. The advantage of this approach is that it provides a portable, standardized, and easy to use solution for the application programmer, and a familiar behavior for the user, typically well versed in the use of WWW browsers. Among the proposed standard description languages, VRML is a aimed at representing three dimensional scenes including hyperlink capabilities. VRML is already used as an import/export format in many 3-D packages and tools, and has been shown effective in displaying complex objects and scenarios. We propose and describe a Prolog library which allows parsing and checking VRML code, transforming it, and writing it out as VRML again. The library converts such code to an internal representation based on first order terms which can then be arbitrarily manipulated. We also present as an example application the use of this library to implement a novel 3-D visualization for examining and understanding certain aspects of the behavior of CLP(FD) programs.
Resumo:
Program specialization optimizes programs for known valúes of the input. It is often the case that the set of possible input valúes is unknown, or this set is infinite. However, a form of specialization can still be performed in such cases by means of abstract interpretation, specialization then being with respect to abstract valúes (substitutions), rather than concrete ones. This paper reports on the application of abstract múltiple specialization to automatic program parallelization in the &-Prolog compiler. Abstract executability, the main concept underlying abstract specialization, is formalized, the design of the specialization system presented, and a non-trivial example of specialization in automatic parallelization is given.
Resumo:
A range of methodologies and techniques are available to guide the design and implementation of language extensions and domainspecific languages. A simple yet powerful technique is based on source-tosource transformations interleaved across the compilation passes of a base language. Despite being a successful approach, it has the main drawback that the input source code is lost in the process. When considering the whole workflow of program development (warning and error reporting, debugging, or even program analysis), program translations are no more powerful than a glorified macro language. In this paper, we propose an augmented approach to language extensions for Prolog, where symbolic annotations are included in the target program. These annotations allow selectively reversing the translated code. We illustrate the approach by showing that coupling it with minimal extensions to a generic Prolog debugger allows us to provide users with a familiar, source-level view during the debugging of programs which use a variety of language extensions, such as functional notation, DCGs, or CLP{Q,R}.
Resumo:
In this paper, calculus of variations and combined blade element and momentum theory (BEMT) are used to demonstrate that, in hover, when neither root nor tip losses are considered; the rotor, which minimizes the total power (MPR), generates an induced velocity that varies linearly along the blade span. The angle of attack of every blade element is constant and equal to its optimum value. The traditional ideal twist (ITR) and optimum (OR) rotors are revisited in the context of this variational framework. Two more optimum rotors are obtained considering root and tip losses, the ORL, and the MPRL. A comparison between these five rotors is presented and discussed. The MPR and MPRL present a remarkable saving of power for low values of both thrust coefficient and maximum aerodynamic efficiency. The result obtained can be exploited to improve the aerodynamic behaviour of rotary wing micro air vehicles (MAV). A comparison with experimental results obtained from the literature is presented.
Resumo:
When users face a certain problem needing a product, service, or action to solve it, selecting the best alternative among them can be a dicult task due to the uncertainty of their quality. This is especially the case in the domains where users do not have an expertise, like for example in Software Engineering. Multiple criteria decision making (MCDM) methods are methods that help making better decisions when facing the complex problem of selecting the best solution among a group of alternatives that can be compared according to different conflicting criteria. In MCDM problems, alternatives represent concrete products, services or actions that will help in achieving a goal, while criteria represent the characteristics of these alternatives that are important for making a decision.
Resumo:
In this work, a unified algorithm-architecture-circuit co-design environment for complex FPGA system development is presented. The main objective is to find an efficient methodology for designing a configurable optimized FPGA system by using as few efforts as possible in verification stage, so as to speed up the development period. A proposed high performance FFT/iFFT processor for Multiband Orthogonal Frequency Division Multiplexing Ultra Wideband (MB-OFDM UWB) system design process is given as an example to demonstrate the proposed methodology. This efficient design methodology is tested and considered to be suitable for almost all types of complex FPGA system designs and verifications.
Resumo:
Las plantas industriales de exploración y producción de petróleo y gas disponen de numerosos sistemas de comunicación que permiten el correcto funcionamiento de los procesos que tienen lugar en ella así como la seguridad de la propia planta. Para el presente Proyecto Fin de Carrera se ha llevado a cabo el diseño del sistema de megafonía PAGA (Public Address and General Alarm) y del circuito cerrado de televisión (CCTV) en la unidad de procesos Hydrocrcaker encargada del craqueo de hidrógeno. Partiendo de los requisitos definidos por las especificaciones corporativas de los grupos petroleros para ambos sistemas, PAGA y CCTV, se han expuesto los principios teóricos sobre los que se fundamenta cada uno de ellos y las pautas a seguir para el diseño y demostración del buen funcionamiento a partir de software específico. Se ha empleado las siguientes herramientas software: EASE para la simulación acústica, PSpice para la simulación eléctrica de las etapas de amplificación en la megafonía; y JVSG para el diseño de CCTV. La sonorización tanto de las unidades como del resto de instalaciones interiores ha de garantizar la inteligibilidad de los mensajes transmitidos. La realización de una simulación acústica permite conocer cómo va a ser el comportamiento de la megafonía sin necesidad de instalar el sistema, lo cual es muy útil para este tipo de proyectos cuya ingeniería se realiza previamente a la construcción de la planta. Además se comprueba el correcto diseño de las etapas de amplificación basadas en líneas de alta impedancia o de tensión constante (100 V). El circuito cerrado de televisión (CCTV) garantiza la transmisión de señales visuales de todos los accesos a las instalaciones y unidades de la planta así como la visión en tiempo real del correcto funcionamiento de los procesos químicos llevados a cabo en la refinería. El sistema dispone de puestos de control remoto para el manejo y gestión de las cámaras desplegadas; y de un sistema de almacenamiento de las grabaciones en discos duros (RAID-5) a través de una red SAN (Storage Area Network). Se especifican las diferentes fases de un proyecto de ingeniería en el sector de E&P de hidrocarburos entre las que se destaca: propuesta y adquisición, reunión de arranque (KOM, Kick Off Meeting), estudio in situ (Site Survey), plan de proyecto, diseño y documentación, procedimientos de pruebas, instalación, puesta en marcha y aceptaciones del sistema. Se opta por utilizar terminología inglesa dado al ámbito global del sector. En la última parte del proyecto se presenta un presupuesto aproximado de los materiales empleados en el diseño de PAGA y CCTV. ABSTRACT. Integrated communications for Oil and Gas allows reducing risks, improving productivity, reducing costs, and countering threats to safety and security. Both PAGA system (Public Address and General Alarm) and Closed Circuit Television have been designed for this project in order to ensure a reliable security of an oil refinery. Based on the requirements defined by corporate specifications for both systems (PAGA and CCTV), theoretical principles have been presented as well as the guidelines for the design and demonstration of a reliable design. The following software has been used: EASE for acoustic simulation; PSpice for simulation of the megaphony amplification loops; and JVSG tool for CCTV design. Acoustic for both the units and the other indoor facilities must ensure intelligibility of the transmitted messages. An acoustic simulation allows us to know how will be the performance of the PAGA system without installing loudspeakers, which is very useful for this type of project whose engineering is performed prior to the construction of the plant. Furthermore, it has been verified the correct design of the amplifier stages based on high impedance lines or constant voltage (100 V). Closed circuit television (CCTV) ensures the transmission of visual signals of all access to facilities as well as real-time view of the proper functioning of chemical processes carried out at the refinery. The system has remote control stations for the handling and management of deployed cameras. It is also included a storage system of the recordings on hard drives (RAID - 5) through a SAN (Storage Area Network). Phases of an engineering project in Oil and Gas are defined in the current project. It includes: proposal and acquisition, kick-off meeting (KOM), Site Survey, project plan, design and documentation, testing procedures (SAT and FAT), installation, commissioning and acceptance of the systems. Finally, it has been presented an estimate budget of the materials used in the design of PAGA and CCTV.