UPEC

This paper addresses the problem of optimal operation scheduling of an individual pumped-storage plant to participate in the energy and regulation markets simultaneously. The goal is achieving of the maximum expected profit when the plant participates in a day-ahead (DA) energy and regulation markets while all of the technical constraints are satisfied. This optimal operation scheduling problem is formulated and solved as a mixed integer programming (MIP) problem. Numerical results for a case study are discussed.

Present day power systems invariably have nonlinear loads, which inject harmonics into the system and give rise to nonsinusoidal voltages and currents. Power quality issues are a prime concern of the power industries as well as of customers. Thus under these conditions, it becomes imperative to study these nonlinear loads; their characteristics and effects. Accordingly, the harmonic analyses have become a regularly used tool in predicting the effects of harmonic producing loads on power systems. State of power system can be obtained in respect to the results of these analyses. The accuracy of these results depends on the modeling of harmonic producing loads. There are a large number of harmonic analysis methods that are in widespread use. In these analyses, the harmonic producing loads are widely modeled by various techniques namely; Constant Current Sources, Norton and Crossed Frequency Admittance Matrix.

The emergence of antibiotic resistance has
increased the interest for finding new antimicrobials in the
past decade. Probiotic Lactic acid bacteria producing antimicrobial
proteins like bacteriocin can be excellent agents
for development as novel therapeutic agents and complement
to conventional antibiotic therapy. Uropathogenic
Escherichia coli, most causative agent of Urinary tract
infection, has developed resistance to various antibiotics. In
the present investigation, antibacterial substance like bacteriocin
(Bacteriocin DT24) produced by probiotic Lactobacillus
brevis DT24 from vaginal sample of healthy Indian
woman was partially purified and characterized. It was
efficiently working against various pathogens, that is, Uropathogenic
E. coli, Enterococcus faecium, Enterococcus
faecalis and Staphylococcus aureus. The antimicrobial
peptide was relatively heat resistant and also active over a
broad range of pH 2–10. It has been partially purified by
ammonium sulfate precipitation and gel filtration chromatography
and checked on reverse-phase high-performance
liquid chromatography. Sodium dodecyl sulfate-polyacrylamide
gel electrophoresis of bacteriocin DT24 was
approximately 7-kDa protein. The peptide is inactivated by
proteolytic enzymes, trypsin and lipase but not when treated
with catalase, a-amylase and pepsin. It showed bacteriostatic
mode of action against uropathogenic E. coli. Such characteristics
indicate that this bacteriocin-producing probiotic
may be a potential candidate for alternative agents to control
urinary tract infections and other pathogens.

This paper presents the simultaneous tuning of power system stabilizers in a multi-machine power system. The problem of selecting the parameters of power system stabilizers in converted into an optimization problem that is solved by genetic algorithm using eigen value based objective function. The dynamic performance of the system has been investigated under small perturbation and large disturbance. The performance of genetic algorithm based PSS has been compared with the conventional power system stabilizer. The non-linear simulation results on 4 machine, 11 bus system verifies the effectiveness of the proposed genetic algorithm based power system stabilizers.

The modelling and simulation of smart meter controlled load blocking scheme to support primary frequency response is investigated. In the proposed scheme, the domestic loads are grouped based on their criticality and essentiality and depending on the drop of frequency each group is blocked. The simulation results were obtained for different losses of generation in the GB power system under

The growing penetration of GD in distribution networks determines a complete redeployment of power flows along distribution feeders, thus causing altered voltage profiles and new issues in protection reliability. This paper addresses the issue of island opening operation, by using detailed models of GD sources and analyzing the frequency and voltage oscillations induced by islanding in different condition of power flow on the interrupted branch. The aim is to identify which network conditions should be considered as possible causes of loss-ofmain protection bad operation.

This paper describes the transient stability analysis of a 10 kV distribution network with wind generators, microturbines and CHP plants. The network being modeled in Matlab/Simulink takes into account detailed dynamic models of the generators. Fault simulations at various locations are investigated. For the studied cases, the critical clearing times are calculated. Some network parameters which influence transient stability are also observed. The compliance of DG protection to stability criteria requirements is further studied. The ride-through capability of the DG units is also investigated through transient stability analysis and the equivalent CCTvoltage dip curves are derived. It is concluded that during fault DG unit availability can be increased through modification of undervoltage protection requirements. Authorized licensed use limited to: Eindhoven University of Technology. Downloaded on April 15, 2009 at 06:15 from IEEE Xplore. Restrictions apply.

In a liberalised market environment, the use of phase shifting transformers (PSTs) or other power flow controlling devices allows the transmission system operator (TSO) to utilise the available grid infrastructure in a more optimal way. In previous work, research has been performed on how to coordinate multiple devices in order to maximise the Total Transfer Capacity. Once the optimal phase shifter settings are determined, the question is how to go from the current setting to this optimal point. In this paper, algorithms are developed to calculate a safe transition between two sets of PST settings. The problem is modelled as a graph in which each combination of PST settings is represented by a vertex (node). Classical shortest path determination algorithms have an unacceptable calculation time for this problem, and an alternative solution must be found. The requirement of the shortest path can be relaxed to a requirement for a good path. This enables the use of a greedy algorithm, which is developed and tested in this paper. Also, an adapted form of the greedy algorithm is proposed, in order to avoid excessive switching between multiple PSTs.

Novel therapeutic approaches are needed to combat the urinary tract infection in women. During menstruation elevated protein
concentration and increase in oxygen and carbon dioxide concentrations with decrease in vaginal Lactobacilli all together
contribute to urinary tract infections. Lactobacillus species are a predominant member of the vaginal microflora and are critical
in the prevention of a number of urogenital diseases. In order to increase antimicrobial potential of vaginal Lactobacilli,
bacteriocin colicin E2 which has specific activity against uropathogenic Escherichia coli has been overexpressed in vaginal probiotic
Lactobacillus brevis DT24. Recombinant Lactobacillus brevis DT24 expressing colicin E2 showed much higher inhibitory activity
against uropathogenic Escherichia coli than wild type L. brevis DT24 in vitro. Efficacy of probiotic Lactobacillus brevis DT24
expressing colicin E2 protein is required for further in vivo evaluation.

This paper presents the development of three phase load flow software by reusing an existing single phase load flow software component. The single phase load flow component was developed using Object Oriented and Component Based Development methodologies. The object oriented power system model of the single phase load flow component was established separately from the mathematical solution. The proposed three phase load flow is formulated based on symmetrical components theory, which involves a positive sequence load flow solution. Based on this relation, the single phase load flow component and its power system model can be reused in the development of the three phase load flow software. The single phase load flow power system model is extended for tnodeling three phase devices such a5 untransposed lines, three phase loads ... etc. Reuse o f the single phase component is achieved through composition relationship, where the positive sequence load flow is modeled as an object inside the three phase load flow component. The three phase load flow is solved by incorporating the solution of both positive sequence load flow and the nodal voltage equations for zero and negative sequence networks.

Abstract Actually, the electric energy has a high importance in all activities, namely, the economic activity and on its development. Sectors of activity like, communications, transports, illumination and many others industrial processes are sustained. With the ...

This article presents the design and implementation of a data communication system over a low voltage power line, meant primarily for applications of data acquisition from sites and monitoring of electrical appliances at the sites. The hardware developed, the interfacing required and the software used for implementation of the protocol are addressed. The developed system has been tested and results in a noise free and noisy power line system are reported. This paper reviews the previous studies on the power line as a transmission medium, proposes and evaluates the noble protocol for such applications

HMM is a pattern recognizer which can classify signals based on waveform and characteristics. Training data-set is achieved by application of k-means clustering approach. First some principle characteristic of the signals is extracted to reduce the computational time of HMM training procedure and enhance discrimination accuracy, and then two HMM blocks is trained for these two kinds of signals. This procedure makes the scheme insensitive to irrelevant disturbances such as CT saturation. Based on the proposed algorithm a high speed differential relaying could be performed in a quarter of a cycle. Small computation requirement is the advantage of this method which can be applied for real time applications. The suitable performance of this method is demonstrated by simulation of different faults and switching conditions on a power transformer. Since the discrimination method is done with probabilistic characteristics of signals without application of any deterministic index, more reliable and accurate classification is achieved. It provides a high operating sensitivity for internal faults and remains stable for inrush currents of the power transformers.

Present day power systems invariably have nonlinear loads, which inject harmonics into the system and give rise to nonsinusoidal voltages and currents. Power quality issues are a prime concern of the power industries as well as of customers. Thus under these conditions, it becomes imperative to study these nonlinear loads; their characteristics and effects. Accordingly, the harmonic analyses have become a regularly used tool in predicting the effects of harmonic producing loads on power systems. State of power system can be obtained in respect to the results of these analyses. The accuracy of these results depends on the modeling of harmonic producing loads. There are a large number of harmonic analysis methods that are in widespread use. In these analyses, the harmonic producing loads are widely modeled by various techniques namely; Constant Current Sources, Norton and Crossed Frequency Admittance Matrix.

Purpose: To study multidrug-resistance in Uropathogenic E. Coli (UPEC) isolated from non-hospitalized patients. Materials and Methods: Altogether, 250 bacterial samples were collected from non-hospitalized patients. Their identifications were done on basis of Gram-staining, colony morphology, biochemical testing and PCR. Susceptibility testing was performed by using standard protocols which were recommended by CLSI. Statistical analysis: For comparisons, statistical analysis was performed by using software, Graphpad Prism 5.0. Results: In total, 32% (n = 80) of the isolates were identified as E. Coli strains and their susceptibility patterns for different antibiotics were determined. The data indicated least resistance against tazocin [(TZP)-1.25%], amikacin [(AK)-1.8%], tigecycline [(TGC)-2.5%] and nitrofurantoin [(F)-3.75%]. For both minocycline (MH) and sulzone (SUL), resistance rate was 5%, for gentamicin (CN), it was 16.25%, while higher resistances were observed against cephalothine [(KF)-70%], cefotaxime [(CTX)-58.5%], ceftazidime [(CAZ)-57.5%], cefepime [(FEP)-55%], cefuroxime and cefixime [(CXM) (CFM)-53.75 %]. Resistance against ciprofloxacin (CIP) was 57.5%, for norfloxacine (NOR), it was 52.5% and incase of sparfloxacin (SPX), it remained 55%. High percentage of the isolates were resistant to cotrimoxazole [(SXT)-86%] and Amoxicillin [AMX-CLA (AMC)-76%]. No resistance against meropenem (MEM) was observed. Conclusion: Highest level of drug-resistance was observed against trimethoprim-sulfamethoxazole (TMP-SMZ) among clinical isolates of uropathogenic E. Coli collected from nonhospitalized patients. Ihsan alI 1 , neeraj Kumar 2 , safIa ahmed 3 , javId Iqbal dastI 4

–Undergraduate student in Malaysia nowadays fear in undertaken of electrical power engineering subjects compare to control and electric circuit subjects. This is due to the complex theories and requires high mathematics applications. This paper is focused on integrating ...

This paper introduces a high-speed relaying approach based on the wavelet anlaysis of the fault generated traveling waves dedicated for high-phase order power transmission lines. In this approach, a suitable wavelet is chosen and tuned at a suitable band of frequencies to capture the fault generated high frequency traveling waves superimposed on the powcr frequency waves in a modal domain. Then, the energies of thc captured signals are used for making a trip decision. The introduced approach is tested and validated by a computer simulation using an ElectroMagnetic Transient Program (EMTDC). The results show that the approach has the ability for high-speed fault detection, cIassification and faulted phase(s) selcction irrespective of the fault inception angle, fault resistance and line termials.

In a competitive world such as ours, students must be prepared beforehand to be autonomous, industrious and skilful. Problem-based learning (PBL) is a methodology that can help the students to explore and put to use their own resources, and it can be applied to a wide range of students and subject matters. The project incorporates aspects of electrical engineering and computing skills. This study is dedicated to the learning process to help students to deal with the complexity of an electric power network. This study has conducted a new methodology in educational research by adopting technology for teaching and learning. PBL, as an instructional strategy of active learning, was used and adapted for use in analysis in electrical power systems programme. This methodology addresses many of the concerns of teachers and professional organizations. Above all, it encourages students to be in charge of their education. It emphasizes critical thinking skills, understanding, learning how to learn, and working cooperatively with others. The benefits of PBL in the electrical power systems course are seen in the way students improved the study and analysis of the security in an electrical power system. This method can also be seen as a benefit for electric power systems where educators strive for improved teaching and learning.