Search results for "POWER"
showing 10 items of 5099 documents
A numerical assessment of the free energy function for fractional-order relaxation
2014
In this paper a novel method based on complex eigenanalysis in the state variables domain is proposed to uncouple the set of rational order fractional differential equations governing the dynamics of multi-degree-of-freedom system. The traditional complex eigenanalysis is appropriately modified to be applicable to the coupled fractional differential equations. This is done by expanding the dimension of the problem and solving the system in the state variable domain. Examples of applications are given pertaining to multi-degree-of-freedom systems under both deterministic and stochastic loads.
Effect of Wind Turbulence on Extreme Load Analysis of an Offshore Wind Turbine
2019
Abstract Evaluation of dynamic responses under extreme environmental conditions is important for the structural design of offshore wind turbines. Previously, a modified environmental contour method has been proposed to estimate extreme responses. In the method, the joint distribution of environmental variables near the cut-out wind speed is used to derive the critical environmental conditions for a specified return period, and the turbulence intensity (TI) of wind is assumed to be a deterministic value. To address more realistic wind conditions, this paper considers the turbulence intensity as a stochastic variable and investigates the impact on the modified environmental contour. Aerodynam…
Dynamic anomaly in the glass transition region of orthoterphenyl
1991
We report on incoherent and coherent neutron scattering results in the supercooled liquid and the glassy regime of the van der Waals fluido-terphenyl using the backscattering and spin echo technique, respectively. A critical comparison of both techniques is presented. The data are analysed in the time domain assuming that microscopic correlation times (τ) scale with the viscosity η according to τ(T)∼η(T)/T. With this assumption we obtain an agreement with several predictions of mode coupling theory: the existence of a critical temperatureT c is shown, independently for both incoherent and coherent data, by a cusp in the temperature dependence of the Debye-Waller factorf Q (T). BelowT c fQ(T…
Growth Volatility Indices
2006
We study the determinants of growth rate volatility in a multisector economy where sectors are heterogeneous in their individual volatility. We propose a model where aggregate volatility is explained by structural change and the size of the economy. We present a first attempt to test these predictions measuring growth volatility by indices based on Markov transition matrices. Growth volatility appears to (i) decrease with total GDP and (ii) increase with the share of the agricultural sector on GDP, although some nonlinearities appear. Trade openness, which we relate to the size of the economy, also plays a role. In accordance with our model, the explanatory power of per capita GDP, a releva…
Neutronic and photonic analysis of the water-cooled Pb17Li test blanket module for ITER-FEAT
2002
Abstract Within the European Fusion Technology Program, the Water-Cooled Lithium Lead (WCLL) DEMO breeding blanket line was selected in 1995 as one of the two EU lines to be developed in the next decade, in particular with the aim of manufacturing a Test Blanket Module (TBM) to be implemented in ITER. This specific goal has been maintained also in ITER-FEAT program even if the general design parameters of the TBMs have reported some changes. This paper is focused on the investigation of the WCLL-TBM nuclear response in ITER-FEAT through detailed 3D-Monte Carlo neutronic and photonic analyses. A 3D heterogeneous model of the most recent design of the WCLL-TBM has been set-up simulating reali…
On the nuclear response of the water-cooled Pb-17Li test blanket module for ITER-FEAT
2003
Abstract Within the European Fusion Technology Programme, the Water-Cooled Lithium Lead (WCLL) DEMO breeding blanket line was selected in 1995 as one of the two EU lines to be developed in the next decades, in particular with the aim of manufacturing a Test Blanket Module (TBM) to be tested in ITER-FEAT. The present paper is focused on the study of the WCLL-TBM nuclear response in ITER-FEAT, being specifically oriented to the investigation of the local effects due to the typical C-shaped tubes of the breeder zone, since they could play a pivotal role in the module-relevant thermo–mechanical design. A 3D heterogeneous model of the WCLL-TBM, realistically simulating its new lay out and taking…
Thermomechanical analysis supporting the preliminary engineering design of DONES target assembly
2018
Abstract The design of the Demo Oriented NEutron Source (DONES) is the main objective of the Work Package Early Neutron Source (WPENS) of EUROfusion Power Plant Physics and Technology (PPPT) programme. DONES is an IFMIF-based neutron source with the goal of testing and qualifying candidate materials to be used in DEMO and future fusion power plants. In the framework of these activities, a research campaign has been carried out at the University of Palermo, in close cooperation with ENEA labs, in order to assess the thermomechanical performances of the DONES target system, endowed with an integrated Target Assembly (TA) when it undergoes the thermomechanical loads typical of its nominal oper…
Ética de las biotecnologías
2002
El poder que la Nueva Genética ha puesto en manos de los seres humanos requiere una ética desde la que sea posible tomar decisiones en cuestiones de manipulación genética. El trabajo se propone (1) situar la ética de las biotecnologías en el conjunto de la bioética, (2) señalar los distintos ámbitos de la Nueva Genética que plantean problemas éticos, reconociendo que cada uno de ellos requiere un tratamiento específico, (3) esbozar un marco ético desde el que orientar las respuestas, un marco elaborado desde la ética kantiana, el enfoque de las capacidades de Sen, la ética del discurso y el principio responsabilidad de Jonas, y (4) abordar la cuestión tal vez más candente en el ámbito ético…
Voltage Security Assessment by Using PFDT and CBR Methods in Emerging Power System
2018
Abstract This paper exhibits varied methods for voltage security assessment in a restructured power system. This paper primarily lays emphasis on two methods that are Probabilistic Fuzzy Decision Tree (PFDT) and Case Based Reasoning (CBR). In PFDT, Decision Tree plays an integral role for classification of system. For further classification of power system security, an algorithm is developed to categorise the buses which trouble the security most. After classification of system, by using minimum amount of load curtailment of voltages on buses which made insecure to secure load. Optimization of load is done by curtailing reactive power from insecure buses. In CBR, old cases from database are…
The Principle of Stasis: Why drift is not a Zero-Cause Law
2016
This paper analyses the structure of evolutionary theory as a quasi-Newtonian theory and the need to establish a Zero-Cause Law. Several authors have postulated that the special character of drift is because it is the default behaviour or Zero-Cause Law of evolutionary systems, where change and not stasis is the normal state of them. For these authors, drift would be a Zero-Cause Law, the default behaviour and therefore a constituent assumption impossible to change without changing the system. I defend that drift's causal and explanatory power prevents it from being considered as a Zero-Cause Law. Instead, I propose that the default behaviour of evolutionary systems is what I call the Princ…