1,432 research outputs found
Stepwise investment plan optimization for large scale and multi-zonal transmission system expansion
This paper develops a long term transmission expansion optimization methodology taking the probabilistic nature of generation and demand, spatial aspects of transmission investments and different technologies into account. The developed methodology delivers a stepwise investment plan to achieve the optimal grid expansion for additional transmission capacity between different zones. In this paper, the optimization methodology is applied to the Spanish and French transmission systems for long term optimization of investments in interconnection capacity
A qualitative research on the experience of education inspectors in the process of fusion and fission
The supervision sub-system of the Ministry of National Education has been changes by Law no. 6764 dated 02.12.2016. In this study, it is aimed to determine the effects of the education inspectors who work in the provinces after the change in the supervisor subsystem. The research is designed as a research on phenomenology. Content analysis was used to analyze the data. The participants are the seven education inspectors who work in the Western Provinces of Turkey. unstructured interview form was used for data collection. The joining and seperation process, election and appointment process, and assignment process were created from the collected data. The joining and seperation process themes is composed of the sub-themes "Structure regulations" and "using the informal communication process". The election and appointment process themes is composed of the sub-themes "The validity and reliability of the interview is low" and "no appointment for all staff". The assignment process themes is composed of the sub-themes "authority limitation", "assignment outside duty area" and "excess workload". The process that has taken place has caused different negative feelings to be experienced with insufficient morale in the inspectors
Gelatin-Sealed Dacron Graft is not more Susceptible to MRSA Infection than PTFE Graft
ObjectivesThe purpose of this experimental study was to compare the susceptibility of gelatin-sealed Dacron and PTFE prostheses to infection by MRSA.DesignProspective, randomized, controlled animal study.Materials and MethodsGraft infections were established in the subcutaneous tissues of 60 female Spraque-Dawley rats by the implantation of gelatin-sealed Dacron or PTFE prostheses followed by topical inoculation with methicillin-resistant Staphylococcus aureus. The study groups were as follows: (1A) uncontaminated gelatin-sealed Dacron group, (1B) untreated contaminated gelatin-sealed Dacron group, (1C) contaminated gelatin-sealed Dacron group with intraperitoneal teicoplanin treatment, (2A) uncontaminated PTFE group, (2B) untreated contaminated PTFE group, and (2C) contaminated PTFE group with intraperitoneal teicoplanin treatment. The grafts were removed after 7 days and evaluated for infection by counting the number of adherent bacteria on the graft material after rinsing and sonication. The perigraft tissue was harvested for histopathological study. To investigate the existence of any infection, blood samples were collected by cardiopuncture for a culture analysis.ResultsNo significant difference in bacteria counts was observed between gelatin-sealed Dacron and PTFE grafts. In groups 1A and 2A, there was no infection detected. The bacterial counts for MRSA were 7.4×105 in group 1B and 8.6×105 in group 2B. There was also no infection in groups 1C and 2C. While the difference between group 1B and 2B was not significant (p>.05), bacterial counts in group 1B or 2B were significantly higher than those in other groups. Blood cultures were only positive in four rats in group 1B and in two rats in group 2B. The severities of the inflammation of the perigraft tissues was low in groups 1A and 2A, high in groups 1C and 2C, and between the range from low to moderate in groups 1B and 2B.ConclusionThe susceptibility of gelatin-sealed Dacron to bacterial infection was not higher than that of PTFE
SPH based numerical treatment of the interfacial interaction of flow with porous media
In this paper, the macroscopic equations of mass and momentum are developed and discretised based on the Smoothed Particle Hydrodynamics (SPH) formulation for the interaction at an interface of flow with porous media. The theoretical background of flow through porous media is investigated in order to highlight the key constraints which should be satisfied, particularly at the interface between the porous media flow and the overlying free flow. The study aims to investigate the derivation of the porous flow equations, computation of the porosity, and treatment of the interfacial boundary layer. It addresses weak assumptions that are commonly adopted for interfacial flow simulation in particle‐based methods. As support to the theoretical analysis, a 2D weakly compressible SPH (WCSPH) model is developed based on the proposed interfacial treatment. The equations in this model are written in terms of the intrinsic averages and in the Lagrangian form. The effect of particle volume change due to the spatial change of porosity is taken into account and the extra stress terms in the momentum equation are approximated by using Ergun's equation and the Sub‐Particle Scale (SPS) model to represent the drag and turbulence effects, respectively. Four benchmark test cases covering a range of flow scenarios are simulated to examine the influence of the porous boundary on the internal, interface and external flow. The capacity of the modified SPH model to predict velocity distributions and water surface behaviour is fully examined with a focus on the flow conditions at the interfacial boundary between the overlying free flow and the underlying porous media
Long term investment optimization methodology for multi-zonal transmission expansion
This paper introduces a stepwise investment optimization methodology for transmission system expansion planning. The objective of the developed methodology is to determine transmission expansion plans to realize a desired interconnection capacity between multiple zones minimizing investment and operational costs. The methodology uses MILP optimization and a modified A∗ shortest path algorithm sequentially in order to determine the optimal investment time point, transmission topology, technology and routing. Spatial constraints and their effects on the installation cost are taken into account in the technology and route optimization. A possible application of the methodology is demonstrated on a stepwise investment plan for the North Sea region
Physicochemical Factors on The Hydrolysis of Dipyrone
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/109863/1/cptclpt2003194.pd
Circular Average Filtering and Circular Linear Interpolation in Complex Color Spaces
In color spaces where the chromatic term is given in polar coordinates, the
shortest distance between colors of the same value is circular. By converting
such a space into a complex polar form with a real-valued value axis, a color
algebra for combining colors is immediately available. In this work, we
introduce two complex space operations utilizing this observation: circular
average filtering and circular linear interpolation. These operations produce
Archimedean Spirals, thus guaranteeing that they operate along the shortest
paths. We demonstrate that these operations provide an intuitive way to work in
certain color spaces and that they are particularly useful for obtaining better
filtering and interpolation results. We present a set of examples based on the
perceptually uniform color space CIELAB or L*a*b* with its polar form CIEHLC.
We conclude that representing colors in a complex space with circular
operations can provide better visual results by exploitation of the strong
algebraic properties of complex space C.Comment: 10 page
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