Optimum Parallel Processing Schemes to Improve the Computation Speed for Renewable Energy Allocation and Sizing Problems

The optimum penetration of distributed generations into the distribution grid provides several technical and economic benefits. However, the computational time required to solve the constrained optimization problems increases with the increasing network scale and may be too long for online implementations. This paper presents a parallel solution of a multi-objective distributed generation (DG) allocation and sizing problem to handle a large number of computations. The aim is to find the optimum number of processors in addition to energy loss and DG cost minimization. The proposed formulation is applied to a 33-bus test system, and the results are compared with themselves and with the base case operating conditions using the optimal values and three popular multi-objective optimization metrics. The results show that comparable solutions with high-efficiency values can be obtained up to a certain number of processors

Seasonal Impacts on the Storage Capacity of EV Parking Lots

Electric vehicles (EVs) are the new bilateral assets of evolving smart electricity grids. Depending upon the technical benefits or economic expectations, they can be considered as non-stationary loads or they can serve as distributed storage units. Moreover, their behavior may change more than once a day. Therefore, their integration is both a challenge and an opportunity for smart power systems. From the point of electricity grids, parking lots (PLs) provide an occasion of supporting the grid by aggregating meaningful number of EVs. Car arrival departure pattern dominates the storage capacity of the PL. However, this pattern is sensitive to seasonal effects. The objective of this paper is to investigate this seasonal impacts of the environment on the storage capacity of the PL. Simulations are performed using car arrival/departure data of a representative PL in Istanbul. Time-dependent car park storage capacity of the PL is determined for a weekday for several periods of the year. The results are discussed from the point of distributed-storage availability of the grid

Impacts of Transactive Energy Trading on the Load Point Reliability Indices of LV Distribution System

The optimal allocation of renewable energy sources and energy storage systems in medium-voltage distribution grids to achieve several objectives was followed by low-voltage applications. However, the main obstacle against large-scale renewable penetration at low voltage grids has been found as a centralized energy market structure where it is almost impossible to achieve all the benefits of renewable energy sources. At this point, the transactive energy market, which enables selling the surplus energy of the distributed generation owners to a consumer in their neighborhood or reverse feeding the utility through intelligent metering devices, is an attractive option. This paper presents how the transactive energy market can improve renewable energy share and customer reliability in the low voltage distribution grid. The impact of the increase in the number of prosumers who prefer to participate in the market on load point reliability indices has been studied in detail. European low voltage Test Feeder is used as an application system with sun irradiation and PV generation in a specific geographical area in Turkey. Energy market prices and their estimated future are also based on Turkey’s market prices. Reliability indices for a different number of prosumers in the network have been evaluated, and discussion has been provided regarding the network reaction to the increase in the number of prosumers. The results show that installing low voltage PV systems is an uncoordinated process, which requires a pre-simulation to estimate the economic benefits for the prospective prosumer locations, considering the consumer intentions on supply preferences

Verrucous carcinoma of the temporal bone

PubMedID: 18061837Verrucous carcinoma is a highly differentiated variant of squamous cell carcinoma. In the literature, 11cases of primary verrucous carcinoma of the temporal bone have been reported. We present a 48-year-old woman who had undergone radical mastoidectomy because of chronic otitis media 20 years ago; consequently, verrucous carcinoma occurred in the mastoid cavity. We discuss verrucous carcinoma of the temporal bone with the review of literature. © 2008

Reinforcement of the distribution grids to improve the hosting capacity of distributed generation: Multi-Objective Framework

Excessive penetration of renewable energy resources into the distribution grid without additional preventive measures has led to several operational problems. However, most strategies developed to accommodate more renewable energy units suffered from other operational problems. Therefore, further efforts are needed to address the other key vulnerabilities of the grid in addition to maximizing the hosting capacity. In this regard, this study is devoted to a new multi-objective formulation to maximize the hosting capacity and minimize the total energy losses while satisfying the operational constraints and maximizing the energy transferred to off-peak hours. The Multi-Objective Advanced Gray Wolf Optimization (MOAGWO) algorithm is used as a solution tool. The proposed formulation and solution algorithm are tested on IEEE-33-bus and 69-bus medium voltage test systems. The impacts of energy storage systems, voltage regulators, and static var compensators on the hosting capacity and the objective functions are identified using several scenarios. The results showed that the optimal device type and locations depend on the level of DG penetration. Finally, a comparison according to two popular multi-objective performance indices showed that the quality of the Pareto front distribution obtained by MOAGWO was better than the ones obtained with the two other popular heuristic methods

Influences of Multimedia Lesson Contents On Effective Learning

In the information era that we experience today, there is a rapid change in the methods, techniques and materials used for education and teaching. The usage of information and communication technology-assisted teaching materials are becoming more commonplace. Parallel to these developments, the Ministry of National Education took steps to develop IT substructures of all schools in the country and implemented many projects. The purpose of this study is to determine whether or not the multimedia lesson content used by teachers affect effective learning. This study is a qualitative study, conducted with 45 teachers working in primary schools during the 2011-2012 academic year. According to the study findings, participants believe that using multimedia lesson content during lectures increases student motivation, makes students more curious and interested, and think that using multimedia lesson content has positive effects

The effect of zoledronic acid on middle ear osteoporosis: An animal study

PubMedID: 30481855Hearing function in older patients may be related to bone structure. We conducted an experiment to evaluate the effect of zoledronic acid on osteoporotic middle ear ossicles in an animal model. Our subjects were 19 female New Zealand white rabbits (38 ears) weighing 2 to 4 kg. We divided the rabbits into three groups: One group consisted of 6 rabbits with osteoporotic ears that were treated with zoledronic acid; the second group was made up of 8 rabbits with osteoporotic ears that were not treated; a control group included 5 rabbits with normal ears that were untreated. After an oophorectomy, the 6 study rabbits were administered 0.1 ml/kg of zoledronic acid intravenously. All rabbits were sacrificed 16 weeks later, and the middle ear ossicles were removed for investigation under light microscopy. Although osteoporosis enhanced the osteoclastic bone resorption of the ossicles, zoledronic acid enhanced osteoblastic activity on osteoporotic middle ear ossicles. The incidence of osteoporosis was 93.8% in the untreated osteoporosis group and 33.3% in zoledronic acid group-a statistically significant difference (OR: 0.24; 95% CI: 0.09 to 0.58; p < 0.001). Osteoporosis appears to increase the resorption of the middle ear ossicles, a process that can be avoided with zoledronic acid administration. Prevention of the effects of osteoporosis in humans may help decrease the irreversible changes in the middle ear ossicles. © 2018 Medquest Communications LLC. All rights reserved