Reactive Security for Smart Grids Using [email protected] Simulation and Reasoning

Smart grids leverage modern information and communication technology to offer new perspectives to electricity consumers, producers, and distributors. However, these new possibilities also increase the complexity of the grid and make it more prone to failures. Moreover, new advanced features like remotely disconnecting meters create new vulnerabilities and make smart grids an attractive target for cyber attackers. We claim that, due to the nature of smart grids, unforeseen attacks and failures cannot be effectively countered relying solely on proactive security techniques. We believe that a reactive and corrective approach can offer a long-term solution and is able to both minimize the impact of attacks and to deal with unforeseen failures. In this paper we present a novel approach combining a [email protected] simulation and reasoning engine with reactive security techniques to intelligently monitor and continuously adapt the smart grid to varying conditions in near real-time

Methotrexate in the treatment of steroid dependent asthma1

Despite the role of oral corticosteroids in management of sever asthma, use of these drugs needs careful awareness of its many side effects. There are controversies about the role of methotrexate in lowering the need for corticosteroides in these patients. In this study an attempt has been made to determine methotrexate effects in corticosteroid dependent asthma. Six patients were entered in a double-blind placebo controlled crossover trial and randomly allocated to two groups. Each group got a 12 weeks course of treatment with 15 milligrams of methotrexate or placebo which thereafter was changed to the other regimen. In comparison with placebo, methotrexate caused a 62.5% less need for oral corticosteroid (P<0.01) and a 20% increase in FEV1 (P<0.05). We concluded that the use of low doses of oral methotrexate results in less need for oral corticosteroid in treatment of corticosteroid dependent asthma

An Insight into Practical Solutions for Electric Vehicle Charging in Smart Grid

The electrification of transportation has been developed to support energy efficiency and CO2 reduction. As a result, electric vehicles (EVs) have become more popular in the current transport system to create more efficient energy. In recent years, this increase in EVs as well as renewable energy resources (RERs) has led to a major issue for power system networks. This paper studies electrical vehicles (EVs) and their applications in the smart grid and provides practical solutions for EV charging strategies in a smart power system to overcome the issues associated with large-scale EV penetrations. The research first reviews the EV battery infrastructure and charging strategies and introduces the main impacts of uncontrolled charging on the power grid. Then, it provides a practical overview of the existing and future solutions to manage the large-scale integration of EVs into the network. The simulation results for two controlled strategies of maximum sensitivity selection (MSS) and genetic algorithm (GA) optimization are presented and reviewed. A comparative analysis was performed to prove the application and validity of the solution approaches. This also helps researchers with the application of the optimization approaches on EV charging strategies. These two algorithms were implemented on a modified IEEE 23 kV medium voltage distribution system with switched shunt capacitors (SSCs) and a low voltage residential network, including EVs and nonlinear EV battery chargers

Optimal siting and sizing of multiple active power line conditioners to minimize network THD considering harmonic couplings

Active power line conditioner (APLC) is an advanced shunt active filter that can limit the voltage total harmonic distortion (THDv) of the entire network or a designated area below 5% as recommended by most standards such as the IEEE-519. A research gap in design and implementation of APLCs is the consideration of harmonic couplings, which is an inherent characteristic of most realistic distorted networks. This paper proposes a particle swarm optimization (PSO) algorithm based on smart meter transmitted data for optimal siting and sizing of APLCs that include harmonic couplings of the nonlinear loads. The objective function of the proposed PSO is minimization of cost (associated with APLC size) and network THDv, respectively. For the nonlinear modelling of APLCs, a five-level neutral-point clamped (FL-NPC) inverter equipped with an adaptive hysteresis current control (AHCC) is used. Detailed simulations without and with harmonic couplings are performed in Matlab/Simulink to find the optimal locations and sizes of the APLCs in a 15-bus network with six nonlinear loads

Hybrid Islanding Detection in Microgrid with Multiple Connection Points to Smart Grids Using Fuzzy-Neural Network

© 1969-2012 IEEE. This paper presents a new hybrid islanding detection approach for microgrids (MGs) with multiple connection points to smart grids (SGs) which is based on the probability of islanding (PoI) calculated at the SG side and sent to the central control for microgrid (CCMG). The PoI values are determined using a combination of passive, active, and communication islanding detection approaches based on the utility signals measured at the SGs sides which are processed by discrete wavelet transform using an artificial neural network (ANN). If {\text{PoI}}-{{\rm{ANN}}} is larger than the threshold value (indicating high possibility of islanding) then a more accurate approach based on fuzzy network is used to recompute it ({\text{PoI}}-{{\rm{FUZZY}}}) where the fuzzy parameters are determined by an adaptive neuro-fuzzy inference system. In the proposed technique, an active islanding is only performed when PoI is high and the amplitudes of the disturb signals are proportional to {\text{PoI}}-{{\rm{FUZZY}}}. Furthermore, if the PoI is not correctly received by CCMG, two auxiliary tests will be performed in the MG side to detect islanding. These tests include an intentional passive islanding detection in a short preset time and an active islanding detection with disturb signals proportional to the calculated PoI. Detailed simulations are performed and analyzed to evaluate the performance of the proposed method

Coordination of Generation Scheduling with PEVs Charging in Industrial Microgrids

Conventional industrial microgrids (IMGs) consist of factories with distributed energy resources (DERs) and electric loads that rely on combined heat and power (CHP) systems while the developing IMGs are expected to also include renewable DERs and plug-in electric vehicles (PEVs) with different vehicle ratings and charging characteristics. This paper presents an electricity and heat generation scheduling method coordinated with PEV charging in an IMG considering photovoltaic (PV) generation systems coupled with PV storages. The proposed method is based on dynamic optimal power flow (DOPF) over a 24-hour period and includes security-constrained optimal power flow (SCOPF), IMG's factories constraints, PV storage constraints and PEVs dynamic charging constraints. It will utilize the generators waste heat to fulfill thermal requirements while considering the status of renewable DERs to decrease the overall cost of IMGs. To demonstrate the effectiveness of the proposed method, detailed simulation results are presented and analyzed for an 18-bus IMG consisting of 12 factories and 6 types of PEVs without/with PV generation systems operating in grid-connected and stand-alone modes. The main contribution is including PEVs with dynamic constraints that have changed the nature of scheduling formulation from a simple hourly OPF to a dynamic OPF

The carbonation behaviour of slag-based concrete as a sustainable construction material for rigid road pavement

The carbonation of concrete in structures causes deterioration and a reduction in service life. Carbonation can increase the porosity and reduce the compressive strength in the carbonated zone of concrete. Various studies have been carried out to source alternative binder materials to mitigate greenhouse gas emissions arising from cement production. Sustainable concrete mixes incorporating supplementary cementitious material additions such as ground granulated blast furnace slag (GGBFS) as an environmentally friendly solution to address the fly ash (FA) shortage and decarbonise the cement sector in Australia are becoming increasingly common. In recent times, fly ash supply has been less reliable. Transport for NSW (TfNSW) RMS QA specification 3211 specifies the use of varying quantities of GGBFS as a direct replacement for cement in concrete. The specification prescribes a minimum shrinkage limited ordinary Portland cement content to be used for the carbonation resistance formula to apply with slag-based concretes. However, there are currently some uncertainties regarding the applicability of this formula for high-volume slag use. Finding both the optimal and maximum contents of GGBFS is vital in establishing and validating the usefulness of this carbonation resistance formula. This study assesses the influence of GGBFS content impacting some of the key fresh (slump and air content) and hardened properties (compressive and flexural strengths), and time-dependent (drying shrinkage) and carbonation (carbonation depth and rate) behaviours, of slag-based concretes. The outcome of this research will provide practical solutions for TfNSW in terms of adopting high-volume slag concrete use in rigid road pavements in comparison to conventional OPC and FA-based concretes for adhering to the requirements of RMS QA specifications 3211 and R83

Transbronchial lung biopsy without fluoroscopic guide in Tehran Imam Khomeini’s Hospital (1999)

Background: Transbronchial lung biopsy (TBLB) is an attractive alternative to open lung biopsy as an initial diagnostic procedure for patients with diffuse parenchymal disease or localized densities beyond direct endoscopic vision. TBLB can be carried out safely without fluoroscopy in patients with diffuse lung disease. Since in our bronchoscopic department fluoroscopy is not available, we planned to evaluate the blind (without fluoroscopic guide) TBLB being performed in our department to determine the success rate in obtaining lung tissue, the sensitivity of the procedure and the risk of complications. Materials and Methods: Sixty-Four TBLB were done in our department during a 6 month period (March-September 1999). Results: Lung tissue wasn’t detected in two (3.1 percent) samples. Pathological results were helpful in 46 (71.9 percent) cases. No evidence of hemoptysis was found after the procedure. Three (4.68 percent) cases of pneumothorax was detected. Only one of them required chest tube (1.51 percent). Conclusion: We concluded that blind TBLB was successful in our department with rates of complications comparable to other approved centers

Influence of land use class and configuration on water-sediment partitioning of heavy metals

Influence of land use and population characteristics on solid-liquid partitioning of heavy metals in aquatic ecosystems is little understood. This study hypothesised that the partitioning of heavy metals (Cd, Cr, Cu, Ni, Pb and Zn) between water and sediments is influenced by different land use classes, their configuration patterns including patch density, Shannon's diversity index, largest patch index, and splitting index and population density. Relationships between variables were investigated from different distances to the stream network (sub-catchment and riparian scales) and considering land use patterns within individual land use classes and individual sub-catchments as a whole (class and landscape levels, respectively). The study outcomes confirmed that the influence of land use and configuration on metals partitioning is scale independent. However, population density increases metal bioavailability at the riparian scale compared to the sub-catchment scale. Agricultural lands discharge the highest fractions of dissolved metals at both spatial scales (eigenvectors = 0.409 - sub-catchment, and -0.533 - riparian, whilst metals have opposite loadings). Positive relationships between splitting index and metal partitioning confirmed that the division of anthropogenic land uses into smaller patches reduces water pollution. However, high fragmentation of forested areas increases the fraction of soluble metals. Further, high patch density and patch diversity are beneficial for controlling the solubility of some metals. Configuration metrics at the landscape level fundamentally reproduce the patterns of the largest land use type and are not effective for assessing metal partitioning. Therefore, analyses at the class level are preferred. This research investigation contributes essential knowledge to improve land use management strategies and, thereby, help safeguard urban waterways.</p