1,127 research outputs found
Red blood cell morphology and plasma proteins electrophoresis of the European pond terrapin Emys orbicularis
The European pond terrapin(Emys orbicularis) is a turtle found in southern and central Europe, West Asia and North Africa. In this study, we used juvenile E. orbicularis (females of 4 - 5 years old) which was captured from the different area of the Mazandaran province in April 2006. Blood was collected from the dorsal sinus into EDTA-coated vacutainer tubes. Plasma proteins were quantified and diluted to different ratios. SDS-PAGE was able to resolve 17 bands at minimum concentration of 51.0 mg/wellwhich contain high and low band with molecular weight of 130.0- 132.0 and 20.0-23.0 kDa
Economic assessment of transmission expansion projects in competitive electricity markets - an analytical review
Restructuring of the electricity market has changed many aspects of the transmission system operation and planning. Reliability-Driven and Economic-Driven transmission expansion planning by regulated and private utilities are the substitutes of the traditional Cost-Driven transmission expansion planning. Reliability-based criteria for assessment of the transmission projects are almost well-developed while there exists a lack of a comprehensive framework for the economic evaluation of the transmission projects. Definition of a quantitative and monetary framework for economic evaluation of future transmission projects demands a detailed market analysis. In addition, specific characteristics and responsibilities of the transmission system in the open access structure must be understood comprehensively. To reaching the aforementioned goal, an analytical review on the existing economic assessment methodologies would be highly beneficial for the researchers in this area. Moreover, most of the review literatures on transmission investment in competitive electricity markets are general. These review literatures have tried to address all aspects of this challenging issue with devoting only few paragraphs to economic assessment of transmission projects. Given the aforementioned shortcomings, this article would bridge the gap by the following contributions: Firstly, reviewing available approaches for economic assessment of transmission projects based on research papers and industrial reports, Secondly, analysing the reviewed criteria critically by applying them to a modified Wood and Wollenberg 6-bus case study and Finally, summarizing the key components of a successful Economic Assessment Framework for transmission expansion or upgrade projects. Practical experiences of California Electricity Market, New England Electricity Market, Pennsylvania, New Jersey, and Maryland (PJM) and National Electricity Market, Australia have been accommodated in the article
Derivation of a new mathematical framework for transmission system augmentation using von Stackelberg game
The market-based augmentation of the high voltage transmission systems as a legacy of the previous regulated regimes has been a challenging issue for the central transmission entities. The economic assessment framework for transmission upgrades or expansion projects, considering the interaction of the central transmission entity (CTE) with the electricity market management (MMC) company both as independent players needs to be addressed appropriately at least in the National Electricity Market, Australia. To assist in bridging this gap, this paper introduces a novel metric, namely, the L-Shape Area, for the economic assessment of the transmission expansion options. The proposed methodology employs a von Stackelberg game for the interaction modelling of the central transmission entity and the market management company. The upper subproblem minimises the objective of the CTE as the leader player and the lower subproblem solves the security-constrained economic dispatch as the follower subproblem. The bi-level programming problem has been solved by applying the Kuhn-Tucker optimality conditions to the follower subproblem and the use of a gradient search method to solve the resultant single level non-linear programming problem. A modified IEEE 14-bus test system has been used to show the effectiveness of the proposed formulation
Transmission Augmentation in an Oligopoly Electricity Market - Part II (Numerical Studies)
This paper proposes a Three-Stage Model for transmission augmentation in restructured electricity markets. The mathematical formulation of the model is developed based on the game theory. Transmission Network Service Provider, TNSP, Generating Companies, GenCos, and Market Management Company, MMC, are placed in different stages of the model. These stages are linked to each other using the Leader-followers game and the concept of Nash equilibriums. An increase in transmission capacity can have two benefits for the electricity market; firstly, efficiency benefit in terms of improving the social surplus of the electricity industry, and, secondly, competition benefit which leads to increasing competition among generating companies. The introduced Three-Stage Model can capture both benefits of transmission projects in electricity markets. An effective numerical method is designed for solving the developed Three-Stage Model. A modified IEEE 14 example system is employed to show the effectiveness of the methodology. This paper has been organized in two parts. First part deals with the mathematical formulation of the algorithm and second part deals with the numerical studies. What follows is the second part of the paper
Design and study of a switch reactor for Central Queensland SWER system
Single Wire Earth Return (SWER) systems are awidely applied, low cost electrification method used inmany rural areas. In Central Queensland a single SWERsystem supplying approximately 100kW may extend morethan 300km. Many SWER systems include shunt reactorsto control the effects of the line charging capacitance. Oneeffect, the Ferranti effect, causes the line voltage to risewith the distance. In three phase distribution systems thiseffect is not visible but in SWER systems, this effect makesit difficult to maintain the consumers supply within theacceptable regulation range. As the second effect, theloading of the SWER system supply transformer increases.Controllable shunt reactors are used as one solution to theaforementioned problems.Stanage Bay feeder in Central Queensland area has beenchosen for the installation of the designed shunt reactor.Stange Bay feeder is supplied by an isolating transformerwith the total capacity of 150kVA and the voltage level of22kV.Using the Stanage Bay feeder, this paper details theprocess of design and simulation of a suitable switchreactor. This step has been carried out by firstly, thedesign of the switch reactor and secondly, the propermodelling of the designed reactor for the voltageregulation studies
A Matlab/Simulink Model of Self Excited Induction Generator for an Electrical Brake Application
This paper presents a MATLAB/Simulink dynamic model of an induction generator, which makes simulation studies possible for the design of fuzzy logic controllers for the purpose of controlling the retarding torque output of the generator in an electrical brake application, using the fuzzy logic toolbox of MATLAB. Electrical braking has been proposed in the literature as an alternative to the mechanical braking systems with an advantage of providing lower maintenance costs. An induction generator, acting as a brake, converts the kinetic energy of a vehicle to electrical energy, which can be dissipated in a resistor bank or used in a regenerative mode.The Simulink model developed will be used to design and test controllers for an effective control of the output torque of the electrical brake system
Derivation of a mathematical structure for market-based transmission augmentation in oligopoly electricity markets using multilevel programming
In this paper, we derive and evaluate a new mathematical structure for market-based augmentation of the transmission system. The closed-form mathematical structure can capture both the efficiency benefit and competition benefit of the transmission capacity. The Nash solution concept is employed to model the price-quantity game among GenCos. The multiple Nash equilibria of the game are located through a characterisation of the problem in terms of minima of the R function. The worst Nash equilibrium is used in the mechanism of transmission augmentation. The worst Nash equilibrium is defined as the one which maximises the social cost, total generation cost + total value of lost load. Thorough analysis of a simple three-node network is presented to clearly highlight the mechanism of the derived mathematical structure from different perspectives
Economic Transmission Augmentation With Explicit Modeling of the Competition Benefit
This paper derives and evaluates a mathematical structure for identifying economically-efficient transmission augmentations. The mathematical structure is based on the concepts of sequential-move and simultaneous-move games in applied mathematics. The Nash equilibrium solution concept has been reformulated as an optimization problem in the proposed structure. The problem of multiple Nash equilibria is managed by introducing the concept of the worst-case Nash equilibrium. Both the economic concepts of the "efficiency benefit" and "competition benefit" of the transmission capacity are explicitly modeled in the proposed structure. A simple three-bus example system and Garver's example system are employed and modified to suit the purpose of analysis. A thorough economic study of these example systems is presented to highlight the concept and operation of the proposed mathematical structure from different perspectives. The results demonstrate the utility of the proposed structure for measuring the total economic efficiency benefit of additional transmission capacity
Effect of diethyl maleate on toxicity of linalool against two stored product insects in laboratory condition
Essential oil extracted from plants has been widely investigated for pest control properties, with some proving to be toxic in insect pests. In this study, effect of the synergist diethyl maleate (DEM) on toxicity of one monoterpenoids, linalool was studied against two most common stored-product insects such as Callosobruchus maculatus and Rhyzopertha dominica. Diethyl maleate was combined in mass ratios (1:8 and 1:4) with acetone used and applied on C. maculatus and R. dominica adult. Five concentrations of linalool were tested with four replications at 24 and 48 h with 30 adult insect in each replication. After 24 h of exposure, the LC50 values were estimated to be 23.61 and 31.01 μl/l air, and after 48 h, they were 15.07 and 21.84 for each insect, respectively. A combination of inalool with the synergist after 24 h of exposure, the LC50 values was estimated to be 11.93 and 13.07 μl/l air and after 48 h, they were 7.38 and 7.93, respectively for each insect. The synergist is able to block the specific system of enzymes involved in selection of tolerance in susceptible generations. Diethyl maleate is an inhibitor of glutathione S-transferase (GST) activity. These results show that diethyl maleate decrease doses of linalool.Key words: Diethyl maleate, linalool, LC50, synergism, Rhyzopertha dominica, Callosobruchus maculatus
Unilateral open subtrochanteric fracture in a very low birth weight newborn: A case report
Background: This case report presents an open subtrochanteric fracture in a premature low birth weight newborn, which was treated with intramedullary Kirschner wire. Methods: A neonate with left open subtrochanteric fracture was referred to the orthopedics department of the current study. Pavlik harness was applied yet treatment failed; therefore, an intramedullary Kirschner wire was applied. Results: The pin was maintained for 6 weeks and fracture healing was confirmed by a radiograph. Follow up after 18 months showed complete healing, no limb length discrepancy, and normal gait. Conclusions: In some patients, traditional methods, such as traction, cast, and Pavlik harness cannot be used. Intramedullary Kirschner wire insertion could be an alternative treatment option. © 2018, Trauma Monthly
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