Consideration of Multi-Phase Criterion in the Differential Protection Algorithm for High-Impedance Grounded Synchronous Generators

The generator differential protection is one of the most important electrical protections of synchronous generator stator windings. Its operation principle is based on the comparison of the input current and output current at each phase winding. Unwanted trip commands are usually caused by CT saturation, wrong CT selection, or the fact that they may come from different manufacturers. In generators grounded through high impedance, only phase-to-phase or three-phase faults can be detected by the differential protection. This kind of fault causes differential current to flow in, at least, two phases of the winding. Several cases of unwanted trip commands caused by the appearance of differential current in only one phase of the generator have been reported. In this paper multi-phase criterion is proposed for generator differential protection algorithm when applied to high impedance grounded generators.

An Energy Optimization Criterion for Branching Water Networks

La dependencia energética de las redes hidráulicas para su explotación hace que, a lo largo de los años, sus costos variables lleguen a ensombrecer los costos de construcción o costos fijos. El objetivo de este artículo es la minimización de los costos de explotación en redes ramificadas simples ya existentes y estudia la aplicación de las técnicas de sectorización, junto con el uso de variadores de velocidad, como medida de eficiencia energética. Se sugiere un criterio para determinar bajo qué circunstancias resulta favorable aplicar la sectorización. Se aplica en un caso de estudio real: una red simple ramificada existente con cuatro zonas hidráulicas usada para regadío en la provincia de Segovia, España, resultando en un ahorro energético de un 7.52%, pudiéndose llegar hasta un 26.31%, ampliando la franja horaria del bombeo inicial.

A coupled elastoplastic-damage constitutive model with Lode angle dependent failure criterion

A coupled elastoplastic-damage constitutive model with Lode angle dependent failure criterion for high strain and ballistic applications is presented. A Lode angle dependent function is added to the equivalent plastic strain to failure definition of the Johnson–Cook failure criterion. The weakening in the elastic law and in the Johnson–Cook-like constitutive relation implicitly introduces the Lode angle dependency in the elastoplastic behaviour. The material model is calibrated for precipitation hardened Inconel 718 nickel-base superalloy. The combination of a Lode angle dependent failure criterion with weakened constitutive equations is proven to predict fracture patterns of the mechanical tests performed and provide reliable results. Additionally, the mesh size dependency on the prediction of the fracture patterns was studied, showing that was crucial to predict such patterns

Ultimate bearing capacity at the tip of a pile in rock based on the modifed Hoek-Brown criterion

Highlights of this paper: a method for calculating the ultimate bearing capacity at the tip of a pile is presented; ultimate bearing capacity is generalized for the modified Hoek–Brown criterion; perfect plasticity, isotropy, weightless rock media, without inertial forces, Meyerhof׳s hypothesis are considered; all the formulation can be programmed in a spreadsheet.

An Evaluation of Applicant Tracking Systems for Recruiting Efficiency

The very purpose of a recruiting software program is to help the management of organizations, primarily the HR department to keep track of the job applications. An applicant tracking system can reduce an organization's overall recruitment cost, increase productivity, and raise the level of satisfaction due to faster and better completion of transactions and services. This project analyzes four software providers to discover an applicant tracking system which best suits an organization's recruiting needs. The capstone also highlights that great success an organization can be achieved by significantly improving the delivery of its recruiting services to employees, managers and applicants. The adoption of a well managed applicant tracking system can support this goal.

Vapor-liquid equilibria using the Gibbs energy and the common tangent plane criterion

Phase thermodynamics is often perceived as a difficult subject that many students never become fully comfortable with. The Gibbsian geometrical framework can help students to gain a better understanding of phase equilibria. An exercise to interpret the vapor-liquid equilibrium of a binary azeotropic mixture, using the equilibrium condition based on the common tangent plane criterion (the Gibbs stability test), is presented in this paper. From a T-composition phase diagram for the mixture, the temperature is set at different values: above, intermediate to, and below the boiling temperatures of the pure components, to intersect different regions of the system. Students prepare an Excel spreadsheet where the Gibbs energy of mixing of the vapor and liquid mixtures are calculated and represented over the whole range of compositions and then, apply the Gibbs stability test to ascertain the aggregation state of the system and to calculate the VL phase equilibrium compositions. Finally, Matlab is used to generate the 3D Gibbs energy of mixing surfaces for both phases over the whole range of temperatures which facilitates the geometrical interpretation of the vapor-liquid equilibrium.

Controle judicial de políticas públicas no Brasil : limites da intervenção do poder judiciário na execução de políticas públicas para efetivação dos direitos fundamentais sociais à prestação

O Controle judicial das políticas públicas necessárias para a efetivação dos direitos constitucionais sociais à prestação é tema muito polêmico na atividade jurisdicional brasileira. Há os que defendem a intervenção irrestrita na tarefa de impor à administração pública a qualquer custo a efetivação das políticas públicas de sua competência. Contudo o nosso trabalho defende que a intervenção do Poder Judiciário no controle de políticas públicas é possível, segundo comando constitucional contido no artigo 3º da Carta Magna, mas com limitações para evitar a violação do princípio da separação dos poderes. Para demonstrar a nossa concepção sobre o tema partimos da definição e da natureza dos direitos fundamentais sociais e sua concepção na ordem constitucional brasileira. Analisamos as principais funções dos direitos fundamentais, concentrando a nossa atenção na função prestacional, ou direito a prestação em sentido estrito. Nesse particular passamos a discutir as questões que envolvem a efetivação dos direitos fundamentais sociais, a partir de sua eficácia jurídica e social até aos aspectos referentes a sua concretização. Salientamos que a efetivação dos direitos fundamentais sociais “derivados” passa por uma atividade legislativa de conformação antes de sua efetivação e que os “originais” poderiam ser concretizados imediatamente, sem se descurar da necessidade de outra atividade legislativa de destinação dos recurso públicos através da lei orçamentária, na foi ressaltado que deveria ser tomado como um dos critérios para essa destinação o princípio do “mínimo existencial”. Analisamos a tese recorrente de defesa da administração para justificar a não efetivação dos direitos sociais à prestação, a denominada “tese da reserva do possível”, salientamos que embora relevante, não era absoluto esse argumento. Contudo a atuação jurisdicional no controle das políticas públicas, não pode fugir da atenção aos princípios da razoabilidade e da proporcionalidade.

La consécration du critère de l’« accès au marché » au sein de la libre circulation des marchandises: mythe ou réalité? = Consecration of the criterion of "market access" in the free movement of goods: myth or reality? Research Papers in Law, 04/2011

No abstract.

How to write criterion-referenced tests for Spanish-English bilingual programs /

"The project reported herein was performed pursuant to a grant from the U.S. Office of Education, Department of Health, Education and Welfare."

Terror Lake project, no. 2743 - Alaska : applicant, Kodiak Electric Association, Inc. /

"August 1981."

Optimizing detector placement for high speed isolated signalized intersections using vehicular delay as the criterion.

Texas Department of Transportation, Austin

Brain injury prediction using the translational energy criterion: an experimental study. Final report.

National Highway Traffic Safety Administration, Washington, D.C.