5,048 research outputs found
Proposal of a consistent framework to integrate geothermal potential classification with energy extraction
The classification of geothermal resources is dependent on the estimate of their corresponding geothermal potential, so adopting a common assessment methodology would greatly benefit operators, investors, government regulators and consumers.
Several geothermal classification schemes have been proposed, but, to date, no universally recognised standard exists. This is due to the difficulty in standardising fundamentally different geothermal source and product types. The situation is not helped by the accepted use of inconsistent jargon among the geothermal community. In fact, the term "geothermal potential" is often interpreted differently by different geothermal practitioners.
This paper highlights the importance of integrating the classification of geothermal potential with that of geothermal energy extraction from well-defined development projects. A structured progression, from estimates of in situ quantities for a given prospect to actual production, is needed. Employing a unique, unambiguous framework would ensure that the same resource cannot exist simultaneously under different levels of maturity of the estimate (as in double bookings of resources), which would let stakeholders better assess the level of risk involved and the steps needed for a geothermal potential to achieve commercial extraction
Experimental Validation of Multiphase Flow Models and Testing of Multiphase Flow Meters: A Critical Review of Flow Loops Worldwide
Around the world, research into multiphase flow is performed by scientists with hugely diverse backgrounds: physicists, mathematicians and engineers from mechanical, nuclear, chemical, civil, petroleum, environmental and aerospace disciplines. Multiphase flow models are required to investigate the co-current or counter-current flow of different fluid phases under a wide range of pressure and temperature conditions and in several different configurations. To compliment this theoretical effort, measurements at controlled experimental conditions are required to verify multiphase flow models and assess their range of applicability, which has given rise to a large number of multiphase flow loops around the world. These flow loops are also used intensively to test and validate multiphase flow meters, which are devices for the in-line measurement of multiphase flow streams without separation of the phases. However, there are numerous multiphase flow varieties due to differences in pressure and temperature, fluids, flow regimes, pipe geometry, inclination and diameter, so a flow loop cannot represent all possible situations. Even when experiments in a given flow loop are believed to be sufficiently exhaustive for a specific study area, the real conditions encountered in the field tend to be very different from those recreated in the research facility. This paper presents a critical review of multiphase flow loops around the world, highlighting the pros and cons of each facility with regard to reproducing and monitoring different multiphase flow situations. The authors suggest a way forward for new developments in this area
Overcoming challenges in the classification of deep geothermal potential
The geothermal community lacks a universal definition of deep geothermal systems. A minimum depth of 400 m is often assumed, with a further sub-classification into middle-deep geothermal systems for reservoirs found between 400 and 1000 m. Yet, the simplistic use of a depth cut-off is insufficient to uniquely determine the type of resource and its associated potential. Different definitions and criteria have been proposed in the past to frame deep geothermal systems. However, although they have valid assumptions, these frameworks lack systematic integration of correlated factors. To further complicate matters, new definitions such as hot dry rock (HDR), enhanced or engineered geothermal systems (EGSs) or deep heat mining have been introduced over the years. A clear and transparent approach is needed to estimate the potential of deep geothermal systems and be capable of distinguishing between resources of a different nature. In order to overcome the ambiguity associated with some past definitions such as EGS, this paper proposes the return to a more rigorous petrothermal versus hydrothermal classification. This would be superimposed with numerical criteria for the following: depth and temperature; predominance of conduction, convection or advection; formation type; rock properties; heat source type; requirement for formation stimulation and corresponding efficiency; requirement to provide the carrier fluid; well productivity (or injectivity); production (or circulation) flow rate; and heat recharge mode. Using the results from data mining of past and present deep geothermal projects worldwide, a classification of the same, according to the aforementioned criteria is proposed
Sull'inquadramento sistematico delle obbligazioni nella Parafrasi di Teofilo (e nelle Istituzioni giustinianee)
The contribution deals with the origin of the particular place assigned in the Paraphrase of Theophilos to Obligations in relation to the Institutional System \u2018personae-res-actiones\u2019. The Author suggests that the displacement of Obligations from the field of the res to the field of the actiones and the representation of Obligations as \u201cmothers of actions\u201d, instead of deriving from an existing idea of Theophilos or from a general byzantine view, is influenced by some passages of the Justinian\u2019s Institutions
La trattazione di Gai 3.140-141 sul pretium nella compravendita, tra 'regulae' e ius controversum
The text of Gaius\u2019 Institutes concerning the price of a sale contains a curious peculiarity. Gaius first of
all reports the requisites of the price in the form of peremptory rules, but soon afterwards he indicates
as consequence (nam...) a contrast of views: some jurists admit the relevance of a sale which doesn\u2019t
observe these requisites. The Author suggest that the (merely) apparent contradiction is an example
of the particular approach \u2018operativo-cautelare\u2019 of the whole work: Gaius wants to point out, in a
\u2018warning perspective\u2019, the conditions to be complied so that the effect of the legal transaction is sure
and beyond dispute, by distinguishing from the case in which the effect is uncertain
Beneficia imperiali e 'logica del sistema'. Spunti di metodo tra le righe di Alberto Burdese.
The contribution deals with some hermeneutical positions of classical
Jurists concerning the beneficia imperialia from the point of view of their
deviating from the \u2018ratio iuris\u2019. The Author \u2013 by recalling the metodological
warning of Alberto Burdese about paying vigilant and cautious
attention for the textual data \u2013 examines some sources which regard the
relationship between beneficia and regulae iuris and between beneficia, aequitas,
utilitas and the attribution of the interpretation of beneficia directly to the
Emperor
Advanced thermoplastic resins, phase 2
High temperature structural resins are required for use on advanced aerospace vehicles as adhesives and composite matrices. NASA-Langley developed polyimide resins were evaluated as high temperature structural adhesives for metal to metal bonding and as composite matrices. Adhesive tapes were prepared on glass scrim fabric from solutions of polyamide acids of the semicrystalline polyimide LARC-CPI, developed at the NASA-Langley Research Center. Using 6Al-4V titanium adherends, high lap shear bond strengths were obtained at ambient temperature (45.2 MPa, 6550 psi) and acceptable strengths were obtained at elevated temperature (14.0 MPa, 2030 psi) using the Pasa-Jell 107 conversion coating on the titanium and a bonding pressure of 1.38 MPa (200 psi). Average zero degree composite tensile and compressive strengths of 1290 MPa (187 ksi) and 883 MPa (128 ksi) respectively were obtained at ambient temperature with unsized AS-4 carbon fiber reinforcement
Neutrino masses and mixings in SO(10)
Assuming a Zee-like matrix for the right-handed neutrino Majorana masses in
the see-saw mechanism, one gets maximal mixing for vacuum solar oscillations, a
very small value for and an approximate degeneracy for the two lower
neutrino masses. The scale of right-handed neutrino Majorana masses is in good
agreement with the value expected in a SO(10) model with Pati-Salam SU(4)\ts
SU(2)\ts SU(2) intermediate symmetry.Comment: 11 pages, no figures. References adde
A semi-Lagrangian scheme for the game -Laplacian via -averaging
We present and analyze an approximation scheme for the two-dimensional game
-Laplacian in the framework of viscosity solutions. The approximation is
based on a semi-Lagrangian scheme which exploits the idea of -averages. We
study the properties of the scheme and prove that it converges, in particular
cases, to the viscosity solution of the game -Laplacian. We also present a
numerical implementation of the scheme for different values of ; the
numerical tests show that the scheme is accurate.Comment: 34 pages, 3 figures. To appear on Applied Numerical Mathematic
BISM: Bytecode-Level Instrumentation for Software Monitoring
BISM (Bytecode-Level Instrumentation for Software Monitoring) is a
lightweight bytecode instrumentation tool that features an expressive
high-level control-flow-aware instrumentation language. The language follows
the aspect-oriented programming paradigm by adopting the joinpoint model,
advice inlining, and separate instrumentation mechanisms. BISM provides
joinpoints ranging from bytecode instruction to method execution, access to
comprehensive static and dynamic context information, and instrumentation
methods. BISM runs in two instrumentation modes: build-time and load-time. We
demonstrate BISM effectiveness using two experiments: a security scenario and a
general runtime verification case. The results show that BISM instrumentation
incurs low runtime and memory overheads
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