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Due to the steep rise in grid-connected solar Photovoltaic (PV) capacity and the intermittent nature of solar generation, accurate forecasts are becoming ever more essential for the secure and economic day-ahead scheduling of PV systems. The inherent uncertainty in Numerical Weather Prediction (NWP) forecasts and the limited availability of measured datasets for PV system modeling impacts the achievable day-ahead solar PV power forecast accuracy in regions like India. In this study, an operational day-ahead PV power forecast model chain is developed for a 250 MWp solar PV park located in Southern India using NWP-predicted Global Horizontal Irradiance (GHI) from the European Centre of Medium Range Weather Forecasts (ECMWF) and National Centre for Medium Range Weather Forecasting (NCMRWF) models. The performance of the Lorenz polynomial and a Neural Network (NN)-based bias correction method are benchmarked on a sliding window basis against ground-measured GHI for ten months. The usefulness of GHI transposition, even with uncertain monthly tilt values, is analyzed by comparing the Global Tilted Irradiance (GTI) and GHI forecasts with measured GTI for four months. A simple technique for back-calculating the virtual DC power is developed using the available aggregated AC power measurements and the inverter efficiency curve from a nearby plant with a similar rated inverter capacity. The AC power forecasts are validated against aggregated AC power measurements for six months. The ECMWF derived forecast outperforms the reference convex combination of climatology and persistence. The linear combination of ECMWF and NCMRWF derived AC forecasts showed the best result.

Across the world, the geographical conditions are varied, and the characteristics of dust depend on the local environmental conditions. The solar power generators must incorporate the soiling losses in their estimation for power output and therefore a methodology was developed to estimate the soiling correction factor. After extensive research, a comprehensive review was presented on the effect of soiling on performance of PV plants along with case studies of soiling experiments around the world. A soiling experiment was designed to develop the soiling correction factor. A methodology to calculate the soiling correction factor, which can be implemented in any location, was developed by analyzing the data from the soiling experiment. The effect of rainfall, humidity and wind on soiling was analyzed and documented. The performance of one 20 kWp PV plant was monitored to study the effect of weather-related parameters on the performance. The soiling correction factor varied from -1.36% to 3.67% during the period between June 2018 and June 2019 in Chennai. It was observed that the average PV conversion efficiency of the 20-kW plant was 11.75% and the average PR was 75%. It was observed that the correlation between module temperature and DC power; between humidity and DC power; between GTI and DC power varied every month. The soiling factor developed could be incorporated into the short-term day ahead solar forecasting model. The developed methodology could be applied at the any large-scale solar power plant around the world for yield assessment, designing as well as operational forecasting purposes.

In Tamil Nadu, India, the old wind turbines installed in 1988 have to be repowered and replaced by modern/advanced technological wind turbines. A solar power plant can be set up using the vast area between the wind turbines on the farm. The economic evaluation must be carried out to determine whether this hybrid project is economically beneficial. This article aims to examine the financial viability of repowering old wind turbines with solar power plants’ inclusion. According to the initial investment costs specified within fixed areas and the distance between turbines, the issue is articulated as optimizing the net present value (NPV) of the project. In this study, the economic investigation on the wind farm located in Kayathar was explored by replacing 30 numbers of 200 kW old wind turbines with modern wind turbines of 2000–3000 kW and installing the solar power plant between wind turbines, excluding the shadow region of wind turbines. The HOMER Pro software and Excel spreadsheet were used to analyze the optimal allocation, economic, electricity production, and sensitivity analyses of the effective hybrid systems. The value of electricity prices was measured using the levelized cost of energy and NPV methods. Additionally, a sensitivity analysis of the chosen parameters for the internal rate of return and debt service coverage ratio was estimated for wind and solar hybridization. The economic analysis suggests satisfactory profitability for the project, even without depending on subsidies. Furthermore, sensitivity analysis helps one see the consequences of the risk on the life of the wind farm and its impact on the project’s productivity and performance.

The current research objective is to explore changes in solar radiation variables across the Indian region during the lock-down period. Global Horizontal Irradiance (GHI), Direct Normal Irradiance ...

The power curve is the performance indicator of the wind turbine. The current industry standard warranted by the International Electrotechnical Commission (IEC) 61400-12-1 (IEC 61400-12-1: first edition 2005-12, wind turbines—part 12-1: power performance measurements of electricity producing wind turbines [1]) defines a unique procedure to evaluate a wind turbine’s power curve (for both stall and pitch regulated wind turbine). The IEC 61400-12-1 (IEC 61400-12-1: first edition 2005-12, wind turbines—part 12-1: power performance measurements of electricity producing wind turbines [1]) standard gives a leverage to estimate any incomplete bin of power curve from two adjacent complete bins using linear interpolation method whenever the incomplete bin prevents the completion of test due to data insufficiency. The incomplete bin interpolation approach could add additional uncertainty in the power performance assessment due to the nonlinear power performance characteristics of wind turbines. Especially in stall regulated wind turbine, the approach over estimates the power in incomplete bin about 32% and leading to 1.2% over estimation of annual energy production (AEP). This paper proposes to use scaled down time averaging window data sets instead of traditional interpolation method to evaluate the incomplete bins of IEC power curve by employing the statically strong data points. In this study, thirty second average data sets have been used to evaluate the incomplete bin. The technique has been implemented in both stall and pitch regulated wind turbines power curve data bases and found that the results are reasonable and realistic. The proposed technique improves the power estimation by 30.4% and the AEP by 1.1% in a stall regulated wind turbine when compare to interpolation method. The paper strives to demonstrate that the incomplete bins of IEC database can be filled with the data sets typically averaged over thirty seconds to derive actual IEC power curve.

Indian Government has set ambitious targets for solar PV of 100 GW under the National Solar Mission by the year 2022. The installed capacity has already reached 28GW as on March 2019. The inverter is one of the main components of solar PV conversion system. Due to varying irradiation profile in India, the inverters used in Solar PV applications are subjected to varying levels of DC input power. At present two weighted average methods namely EURO and California Energy Commission (CEC) efficiency formulae have been used by inverter manufacturers worldwide to evaluate the performance of inverters. These methods are representative of inverter efficiencies at Europe and California, thus cannot be suitable benchmarks to find out the conversion efficiency of the inverters in other locations. The present research and this paper proposes about introducing new weighting factors for calculation of inverter efficiency as per irradiation profile in India. As a step 1, for computing the weighting factors the data from Solar Radiation Resource Assessment (SRRA) stations implemented by National Institute Of Wind Energy (NIWE) is used and are categorized into five climatic zones. In step 2 validation of three inverters were done by calculating the weighted average efficiency of these inverters operating in all the climatic zones by considering the new weighting factors. Further in step 3, it was cross-compared with the standard values of EURO and CEC efficiency. In step 4, the modelled overall weighted average efficiency is subsequently compared with the actual measured weighted average efficiency. The measured DC Energy and AC Energy of the plant was used for this purpose. The proposed approach has been generalized to consider the irradiation profile of a particular location for calculating the inverter efficiency and hence it can provide significant insights related to the performance of inverters for the solar projects.

Tamil Nadu is among India's most developed and industrialized states. Onshore wind is the fastest-growing, with Tamil Nadu contributing 23 percent of the total wind capacity installed in India at 37,505 MW. This paper aims to present a preliminary assessment of the potential for wind power to the Tamil Nadu coastal region as estimating the wind characteristics is the first essential step in evaluating a wind energy project. Therefore, it is important to have a thorough understanding of the wind resource. To assess the wind resource, ground-based meteorological masts measurement data from seven selected sites have been used with a wind power density of more than 200 W/m2 spanning between one and two years of data at the height of between 20 m and 100 m. Data is extrapolated to 100 m (at sites where data is not available at 100 m) and derived mean wind speed, average wind density, and Weibull parameters. All seven sites reveal excellent potential with wind power density ranging from 208.64W/m2 in Muttom to 684.2 W/m2 in Kanyakumari, which is the desired electricity generation parameter for the wind turbine option. The exceptional mean wind speed & average wind power density at Dhanushkodi has also been found to be 7.60 m/s & 362.18 W/m2 at 10 m. At all sites, the diurnal patterns were consistent with the coastal regions' trends. The analyzed data is the preliminary characteristic of wind potential, which helps in the conversion of wind power and identifying the state's actual wind potential.

This study was aimed at evaluating the anti-diabetic potential of passion fruit Passiflora edulis (EPE) extracts in diabetic rats, following Streptozotocin (STZ) induced oxidative stress. Thirty adult Wistar rats were divided into five groups, with six rats in each group. The control rats were injected intraperitoneally with citrate buffer (pH 4.5). The remaining groups of rats were administered single dose of 45 mg·kg(-1) of STZ by intraperitoneal route to induce diabetes. The diabetic animals were treated with 250 and 500 mg·kg(-1) of EPE and glibenclamide 0.6 mg·kg(-1) for fifteen days by oral route. Blood glucose, end organ oxidative stress marker, and anti-oxidants were assayed. Further, histopathological investigation of pancreas was studied at the end of the experimentation. The results revealed that subacute administration of EPE significantly (P < 0.001) controlled the blood glucose level in the diabetic rats. In addition, EPE extract protected the end organs by restoring the anti-oxidants enzyme, significantly increasing super oxide dismutase level (SOD) and decreasing catalase (CAT) and TBARS level in visceral organs. In conclusion, that EPE extracts showed anti-diabetic and anti-oxidant potential against streptozotocin-induced diabetes.

In order to perform a stable and reliable operation of the power system network, short term load forecasting is vital. High forecasting accuracy and speed are the two most important requirements of short-term load forecasting. It is important to analyze the load characteristics and to identify the main factors affecting the load. ARIMA method is most commonly used, as it predict the load purely based on the historical loads and no other assumptions are considered. Therefore there is a need for Outlier detection and correction method as the prediction is based on historical data, the historical data may contain some abnormal or missing values called outliers. Also the load demand is influenced by several other external factors such as temperature, day of the week etc., the Artificial Intelligence techniques will incorporate these external factors which improves the accuracy further. In this paper a hybrid model ARIMA — SVM is used to predict the hourly demand. ARIMA is used to predict the demand after correcting the outliers using Percentage Error (PE) method and its deviation is corrected using SVM. Main objective of this method is to reduce the Mean Absolute percentage Error (MAPE) by introducing a hybrid method employing with outlier detection technique. The historical load data of 2014–2015 from a utility system of southern region is taken for the study. It is observed that the MAPE error got reduced and its convergence speed increased.

Two of the potential bacterial isolates, viz., Pseudomonas fluorescens (VCRC B-426) and Bacillus subtilis (VCRC B-471) whose toxins kill the mosquito pupae/larvae have been identified at our center. As the mode of action of these bacteria are not known, an attempt was made to find out the binding sites of the toxic proteins through immunological methods. Antibodies were raised in BALB/c mice and egg yolk system of chicken layers against the mosquitocidal proteins. The antibodies showed specific binding on to the cephalic and thoracic cuticle of the pupae as well as the paddles of the larvae, indicating the binding of the mosquitocidal proteins.

The variable nature of wind and solar will be a challenge for any grid which is not supported with enough flexibility. This issue of variability can be resolved to some extent through utilization of complementary nature of these two resources, which may be better achieved by having optimal mix of these resources. This paper addresses the optimal mix of wind and solar PV capacities for wind-solar PV hybrid power plant subject to constraint of minimum variability in its output power generation, while increasing its mean power output and base load power generation compared to ‘equal distribution’ scenario. This is being addressed through moving-window optimization method, utilizing historical wind and solar PV output power generation data. Based on practical data in Karnataka State system in India, case study has been performed for 42.5 MW wind-solar PV hybrid power plant and it resulted in optimal mix of 22.22 MW and 20.28 MW respectively for wind and solar PV.

Integration of large scale Distributed Generation would call for adequate planning in order to optimize the system operation, enhanced reliability and reduced losses. However, the maximum tolerable DG integration capacity gets limited by voltage variation and power flow constraints. These limitations can be optimized with an automatic reconfiguration of the system based on the present system state and could result in maximizing capacity. The location of switches in a network plays a key role in system reconfiguration. In this paper, a technique for placement of minimal switches in the presence of non-controllable consumer level DGs is developed. The locations are determined based on load flow approach and Monte-Carlo simulations to ensure reliability over random system behavior. The performance of the proposed approach is tested on a simplified distribution network and the effectivity of the numerical results is analyzed.

In India, wind and solar PV generation exhibits complementary characteristics with each other. The study analyses optimizing system elements in existing wind farm by integrating solar PV power plant utilizing the existing infrastructure viz., land, transmission lines, Cables and Transformers, synergies in operations and maintenance. It is shown that there is increase in energy generation per acre with integration of solar PV power plant. Also, resulting cost savings in the capital cost of solar PV power plant will result in a levelized tariff of hybrid combination, which is competitive with that of existing wind farm with normative plant load factors. The levelized tariff will be directly proportional to effective installed capacity of solar PV power plant and inversely proportional to its plant load factor. It also acts as a buffer against low wind speeds as solar PV generation can complement and will reduce the output variability. Integrating solar PV power plant in the existing wind farm will optimize system elements of the wind farm.

Bacillus thuringiensis var. israelensis (B. t. i.) is being widely used in mosquito control programs. However, the large-scale production of this bacillus is expensive due to the high cost of the production medium. In this study, we attempted to develop a cost-effective medium, based on a locally available raw material namely coconut water which is available in plenty as waste product from coconut oil industry. The yield of cell mass, sporulation and mosquito larvicidal activity were studied by growing this bacterium in this waste product and in comparison with the conventional medium (NYSM). Cell mass yield of 3.1 g/L, spore count of 3.4 × 1011 spores/mL and mosquito larvicidal activity (LC50) of 14.85 ng/mL (against early fourth-instar larvae of Aedes aegypti) were obtained with a 30 h old culture of this bacterium grown in coconut water. This is almost similar to that obtained with NYSM medium. Hence, coconut water-based culture medium is economical for the production of B. t. i.

In an attempt to isolate mosquitocidal bacteria, 460 samples of soil, leaf and water were collected from mangrove habitats of Andaman–Nicobar Islands, India. Out of a total number of 857 bacteria screened, three Bacillus strains showed mosquitocidal activity at promising levels. Two of them were identified, morphologically and biochemically, as Bacillus subtilis , whereas one was Bacillus thuringiensis . These strains were code named as B469, B471 and B474, respectively. Molecular characterisation using 16S rRNA confirmed the identity of B469 and B471 as B. subtilis strains and flagellar serotyping confirmed B474 as B. thuringiensis subsp. israelensis/tochigiensis (H14/H19). Amplification of cry and cyt genes of B474 showed the presence of cry 4A, cry 4B, cry 11, cry 10, cyt 1 and cyt 2. Bioassay of the culture supernatants (CS) of B. subtilis strains showed mosquitocidal activity against larvae and pupae of Anopheles stephensi , Culex quinquefasciatus and Aedes aegypti . The mosquitocidal activity was more pronounced with the CS of B471 than that of the B469. Interestingly, CS of both these strains was more active on pupae, a non-feeding stage, than larvae of the mosquitoes tested. The B. thuringiensis strain was able to kill the larvae of all the above mentioned mosquitoes. This is the first study demonstrating mosquito pupicidal activity of B. subtilis strain. Moreover, this is the first report of isolation of a highly active B. thuringiensis subsp israelensis/tochigiensis from India.

Bacillus sphaericus has been widely used in mosquito control programs, but the large-scale production of this bacterium is expensive because of the high cost of the medium. In this study, we attempted to develop a cost-effective medium, based on inexpensive, locally available raw materials including soybean flour (Glycine max) and peanut cake powder (Arachis hypogea) by using 100-l bioreactor. Sporulation, toxicity and biomass were satisfactory after B. sphaericus was produced on both media. Use of the soybean culture medium resulted in “maximum” toxicity (LC50 14.02 ng/ml against third instar Culex quinquefasciatus larvae), highest spore count (3.7 × 109 spores/ml) and maximum biomass (4.6 g/l) within a short fermentation time of 21 h. Hence, this soybean-based culture medium was considered most economical for the large-scale industrial production of B. sphaericus.

With the increasing penetration of Distributed Energy Resources (DERs), a fast and reliable Distribution System State Estimation (DSSE) of a distribution system, with reasonable accuracy, has become vital for all planning and operating studies. However, as a distribution system cannot have measurement devices at all nodes, this estimation must rely on least possible measurements. This paper proposes an algorithm to place the optimum number and location of measurement devices on a radial distribution network. The algorithm is based on backward-forward sweep method for the state estimation and a search algorithm for decision making. The possible uncertainties introduced by the measurement devices and the random changes in the loading conditions are considered to yield a reliable solution to the placement problem. The accuracy of the solution is obtained through a Weighted Least Square (WLS) approach. This approach is demonstrated on a benchmark network.

A group of customers connected to the present power grid are very much sensitive to the power interruptions and as well as power variations. Therefore it is the responsibility of the power utility to provide the reliable service and also in case of power curtailment, utility should promise as maximum as possible amount of power supply to all the connected loads of high priority customers and partial loads of low priority ones. The demand side management system used so far could take care of the consumer convenience to very less extent. There is some contribution towards demand response at the distribution feeder level and at the building area network level, but very less work has been done so far, about the substation level demand response. Therefore this paper proposes a substation management system, in which the demand limit can be allocated by Hierarchical Cumulative Voting (HCV) method based on the assigned weight to the respective consumers. The results show that, the demand limit can be assigned efficiently, which in turn can be used for Demand Response (DR) strategy, when the load exceeds the available power from the utility.

With the Energy policies promoting solar rooftop PV penetration, a rapid rate in its penetration is observed in the Distribution System. As the distribution systems were not designed to have a wide presence of dispersed generation units, the impacts of bidirectional power flow will be significant on all equipments. This will lead to unforeseen variations in voltage profile of the system. This paper analyses the impact of this dispersed generation on the voltage profile of distribution system. To quantify the impact, case studies are carried out on a practical distribution system using MiPowerTM and the simulation results are presented to arrive at the maximum allowable PV penetration considering voltage level constraints. The analysis could serve as a feasibility study report for utilities promoting dispersed generators in India.

This paper, discusses about a systematic approach to calculate the dynamic compensation for a wind farm to enhance Fault Ride Through (FRT) Capability. In this approach the generator parameters like critical slip and critical voltage are probed and the size of the dynamic compensation is calculated. This method is applied to Squirrel Cage and Wound Rotor induction generators (SCIG & WRIG). The critical slip of the induction machine is calculated by using torque-speed characteristics and equivalent circuit model. The variation of real and reactive power of the SCIG or WRIG from rated slip to the critical slip is analyzed and the critical voltage is computed. The practical wind farm considered in the study has fixed speed induction generators. The capacity and location of dynamic VAR compensation is determined based on the critical voltage of the induction generators. The detailed wind farm and the grid are modeled in MiPower™ simulation environment. The improvement in fault ride through capability is analyzed for different case studies.

Methanolic extracts of 20 medicinal plants were screened at 1-10 mg/ml for in vitro macrofilaricidal activity by worm motility assay against adult Setaria digitata, the cattle filarial worm. Four plant extracts showed macrofilaricidal activity by worm motility at concentrations below 4 mg/ml and an incubation period of 100 min. Complete inhibition of worm motility and subsequent mortality was observed at 3, 2, 1 and 1 mg/ml, respectively, for Centratherum anthelminticum, Cedrus deodara, Sphaeranthus indicus and Ricinus communis. 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide (MTT) reduction assay was carried out at 1 mg ml(-1) and 4-h incubation period, and the results showed that C. deodara, R. communis, S. indicus and C. anthelminticum exhibited 86.56, 72.39, 61.20 and 43.15% inhibition respectively in formazan formation compared to the control.

The glutathione S-transferases (GSTs; EC 2.5.1.18) comprise a family of widely distributed Phase II detoxication enzymes that catalyse the conjugation of a broad variety of reactive electrophiles to the nucleophilic sulfur atom of the major intracellular thiol, the tripeptide glutathione. The diverse functions, including catalytic GSH conjugation, passive ligandin-type binding and modulation of signal transduction, may be selectively targeted by different inhibitors. GST inhibitors are emerging as promising therapeautic agents for managing the development of resistance amongst anticancer agents. In diagnostic medicine, as well as in antiparasitic drug development, GST inhibitors are important lead molecules. In this review, the important molecules known for their GST inhibition together with potential therapeutic uses are summarised.

Bacillus thuringiensis var israelensis (B.t.i.) has been widely used in mosquito control programs, but the large scale production of this bacillus is expensive because of the high cost of the medium. In this study, we attempted to develop a cost-effective medium, based on inexpensive, locally available raw materials including soybean flour (Glycine max), groundnut cake powder (Arachis hypogea), and wheat bran extract (Triticum aestivum) by using 100-L fermentor. Sporulation, toxicity, and biomass were satisfactory after B.t.i. was produced on all the three media. Use of the soybean culture medium resulted in maximum toxicity (LC50 8.89 ng/ml against Culex quinquefasciatus IIIrd instar larvae), highest spore count (0.48 × 1011 c.f.u./ml), and maximum biomass (7.8 g/L) within a short fermentation time of 24 h. Hence, this soybean-based culture medium was considered most economical for the large scale industrial production of B.t.i.

A generalized boundary-continuous displacement based double Fourier series solution to the boundary-value problem of free vibration of thin anisotropic fiber reinforced plastic (FRP) rectangular plates is presented. The transverse vibrational characteristics of laminated anisotropic plates with arbitrary combinations of admissible boundary conditions are theoretically investigated. Numerical results presented here pertain to the natural or resonant frequencies of five-layer symmetric cross-ply plates with all edges clamped, and rotated cross-ply anisotropic plates with all edges simply supported, which are, in turn compared with the corresponding experimental results for two sets of glass fiber reinforced plastic (GFRP) thin anisotropic rectangular plates, fabricated using two different techniques. The influence of possible defects generally encountered in the fabrication process on the experimentally obtained resonant frequencies is also discussed here. ? 2004 Elsevier Ltd. All rights reserved.

Secondary metabolites produced by Trichoderma viride, a deuteromycetes fungus, under submerged culture condition were formulated and evaluated for oviposition attractancy against gravid females of Culex quinquefasciatus mosquito. At a concentration of 10 µg ml-1 the formulation showed remarkable attractancy with an oviposition active index (OAI) of +0.52. When the oviposition attractancy of the formulation was compared with a known oviposition attractant, p-cresol, both at 10 µg ml-1, the former was found to be more attractive to result in 70% egg laying than the later with 30% egg laying. Thin layer chromatography fractions of the secondary metabolites showed that a fraction with Rf value of 0.88 was highly active as oviposition attractant with an OAI of +0.65. Further work on identification of the active principle(s) of the microbial formulation might lead to an oviposition attractant useful in mosquito vector management.

Larvicidal efficacy and residual activity of a floating sustained release formulation of Bacillus thuringiensis ssp. israelensis ( Bti ) was tested in polluted water habitats against Culex quinquefasciatus , the vector of bancroftian filariasis, breeding in cesspools and cesspits. A total of 25 habitats having 65 m 2 water surface area with C. quinquefasciatus immatures were treated with the formulation at the rate of 15 kg/ha. For comparison, in another area, 18 habitats with a water surface area of 70 m 2 were kept untreated. Evaluation was continued up to 179 days with three rounds of Bti application. The mean number of egg rafts did not differ significantly between treated and untreated habitats during the trial period indicating same level of recruitment. However, abundance of larvae and pupae was significantly lower in Bti treated habitats compared to that in untreated ones. The activity of the formulation, with 2 weeks delay in onset compared to treatment, caused > 80% reduction in pupal abundance for a period of 30–34 days. Considering this, it is suggested that monthly application of Bti formulation will considerably reduce the recruitment of pupae of C. quinquefasciatus .

The macrofilaricidal property of the plant, Plumbago indica/rosea, was investigated in vitro against Setaria digitata, a filarial parasite of cattle. Adult worms were incubated in a medium containing crude extract at concentrations 0.05, 0.04, 0.02, and 0.01 mg mL−1 for various incubation periods of 30 min, 1 h, 2 h, and 6 h, respectively, at 37°C and the worm motility was compared with that of solvent control worms kept in drug-free medium. Complete inhibition of motility was observed for concentrations ranging from 0.02 to 0.05 mg mL−1, whereas in the control all the worms were active. Bioassay-guided fractionation of the crude extract by silica gel column chromatography resulted in the identification of a very active fraction. The activity of this fraction against adult worms was further confirmed by 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide–formazan colorimetric assay, which gave >50% inhibition for the active fraction at concentrations 0.05, 0.002, 0.005, and 0.0006 mg mL−1 at 30 min, 1 h, 2 h, and 6 h incubation periods, respectively. The physical and chemical data obtained from melting point determination, thin-layer chromatography and high-performance liquid chromatography analysis and IR, 1HNMR, 13CNMR, and gas chromatography-mass spectrometry spectral analysis have indicated the chemical structure of the active molecule as 5-hydroxy-2-methyl-1,4-naphthalenedione (plumbagin). Drug Dev. Res. 56:33–39, 2002. © 2002 Wiley-Liss, Inc.

A formulation was developed from the metabolite(s) of a novel Pseudomonas fluorescens Migula strain (VCRC B426) and tested against 4th-instar larvae and pupae of three species of vector mosquitoes, Anopheles stephensi Liston, Culex quinquefasciatus Say and Aedes aegypti (L). The larvae and pupae of An. stephensi were the most susceptible to the formulation, followed by those of C. quinquefasciatus and Ae. aegypti, in that order, and the dosage requirement for pupal mortality was less than that required for larval mortality. The LC50 dosage requirements for larvae of these mosquito species were, respectively, 70.4, 511.5 and 757.3 microg protein ml(-1), whereas for pupae they were, respectively, 2.0, 9.4 and 19.2 microg protein ml(-1). The lethal fraction was purified from the culture broth and its molecular mass, as determined by high performance liquid chromatography, was 44kDa. This is the first report of a microbial formulation acting upon mosquito pupae, a non-feeding stage. Its mode of action and efficacy to control mosquitoes under field conditions need to be studied further.

Development of Wuchereria bancrofti in Culex quinquefasciatus emerged from the larvae that survived the exposure of sub-lethal dose of Bacillus sphaericus was examined in the laboratory. Third instar larvae of Cx. quinquefasciatus were treated with B. sphaericus at a sub-lethal dose of 11.35 microg/250 ml. The female mosquitoes that emerged from the survived larvae were fed on microfilaraemic human blood and parasite development was monitored in the fed mosquitoes. Both treated and untreated mosquitoes could ingest microfilaria (mF) equally as there was no significant difference in mF density between them. But, density of developmental stages of the parasite in treated group was significantly lower. Since, there was no mortality of mosquitoes, the lower density of the developmental stages could be attributed to the loss of parasites in the treated mosquitoes. Consequently, the proportion of mosquitoes with infective larvae (L3) and number of L3 were also significantly lower in treated females. Delay in parasite development was also noticed in treated mosquitoes. The present study indicates that B. sphaericus, when applied at sub-lethal dose kills larvae, and in addition, inhibits development of the filarial parasite and consequently reduces L3 yield in adult mosquitoes that emerged from the survived larvae.

The mosquito Culex quinquefasciatus Say (Diptera: Culicidae) is the vector of the filarial parasite Wuchereria bancrofti (Cobbold) (Spirurida: Onchocercidae), which causes human bancroftian filariasis. Information on the mosquito humoral response against the filarial parasite during the process of its infection and development is important, as it decides the vector competence of the mosquito. Visible changes in the haemocyte population of mosquito, if any, will be an indicator of the possible humoral factors. The present study was aimed at investigating changes in the populations of various types of haemocytes of Cx. quinquefasciatus following infection with W. bancrofti. On day 2 post-feeding on microfilaraemic blood, the haemolymph perfusate of infected mosquitoes with L1 stage of the parasite showed 44.1% granulocytes, 42% prohaemocytes and 13.9% plasmatocytes, whereas that of the control mosquitoes fed on amicrofilaraemic blood showed 63.4% plasmatocytes, 22.2% prohaemocytes and 14.4% granulocytes. Differences in the population numbers of haemocyte types between the infected and control were significant (P > 0.05). However, the mosquitoes examined on day 6 post-feeding, when the parasite was in L2 stage, did not show any such changes. But, similar changes reappeared on day 12 in mosquitoes with L3 stage of the parasite. The observed haemocyte population changes indicate the possibility of some amount of humoral immune response, through the production of certain immune molecules, in Cx. quinquefasciatus infected with W. bancrofti. The nature and exact role of such a response on the filarial parasite development need further investigation.

The rapid increase in the wind power penetration into power system introduces more variability and uncertainty in existing conventional power system. These factors are the key challenges to integrate large amounts of wind generation into future smart grid. Wind power ramp forecasting provides the additional dimensionality in wind power forecasting and risk involved in operations at times of high variability in terms of ramp ups and ramp downs. This paper addresses the wind ramp rates considering wind effects along with demand profile. The analysis is applied to one of the high wind penetrating states in India to understand the effect of wind power ramp forecasting. The presented analysis can be used for scheduling/dispatch of conventional generation units using stochastic unit commitment programs.

Power systems with high wind penetration undergo increased variability and uncertainty, this leads to significant research in finding the wind power capacity credit on generation adequacy. The deterministic methods used in the past does not reflect the stochastic or probabilistic nature of system behavior with regard to customer demands, component failures and intermittent nature of renewable energy sources in particular wind energy sources. It is observed that large scale integration of wind energy has an impact on power system planning and operation. The large scale wind integration calls for generation planning which is an important aspect in order to meet the customer demands with optimum mix of generation like thermal, hydro and renewable. In this paper, probabilistic method namely sequential Monte-Carlo simulation has been implemented and is validated with IEEE RTS for generation adequacy analysis. The wind model has been incorporated in Monte-Carlo simulation approach in order to find the impact of the intermittent energy sources on generation planning in terms of wind power capacity credit. In the present paper, one of the high wind penetration states in INDIA has been considered for case studies. The capacity credit of wind power has been estimated with the planned generation for next five years considering the reliability index as per GRIDCODE.

The utilization of wind powera major renewable energy source is expected to constantly increase during the next few years. Interaction between the Wind Farms (WFs) and the grid needs to be investigated for different power system studies. A number of issues related to the influence of large wind power penetration into the grid are evacuation feasibility; transient stability and the ensuing short-circuit levels. This paper focuses on the short circuit contribution from wind farms to the grid when integrated to large power systems. To determine the short circuit level of a large wind farm, it is necessary to utilize the equivalent model to minimize the modeling complications. The simulations presented in the literature show that the fault current contribution from equivalent model has large variation as compared to individual turbine models. Hence this paper focuses on improvements of equivalent technique for short circuit studies. Case studies are carried out on different wind farms to determine the fault current contribution.

The contribution of wind power in supporting the electricity demand is one of the key areas in wind integration studies. Wind generation is different from conventional units as the available outputs of different wind farms cannot be approximated as being statistically independent, and hence near-zero variable output is possible across an entire power system. Power system operators are evolving alternate approaches, by changing the rules and practices which were used in past based on history of operations. This paper addresses the understanding the variability of wind power along with demand profile through probabilistic data analysis. The analysis of data has been carried out over different months/seasons. The load following and regulation for each day over a span of one year has been computed to help the operator to understand the spinning reserve requirements and to determine the day ahead conventional generation scheduling. Through this paper an effort has been made to understand the applicability of wind power data in future operation of power system with large penetration of variable generation. Case studies have been carried out for one of the high wind penetrating states of Southern India.

The longevity, migration and distribution of infective larvae (L3) of Wuchereria bancrofti within the host mosquito were studied by feeding Culex quinquefasciatus on microfilaraemic human blood and allowing the microfilariae to develop to L3. The L3 were found to remain alive and active for 46-50 days, i.e. as long as the host mosquitoes survived. The larvae started their migration to the head of the mosquito soon after their development to L3, on day 13 after the initial, infective bloodmeal. Although more L3 were usually found in the head region of the mosquitoes than in the thorax or abdomen, the larvae showed an oscillatory pattern of movement between all three regions. This movement was significant in the mosquitoes fed only on microfilaraemic blood, but not in those that took a second bloodmeal on normal human blood on day 8 after the infective bloodmeal. The distribution of the L3 in the three regions of the mosquitoes was independent of parasite density. Observations on L3 movement over a 24-h period indicated that there were always more L3 in the head than in the thorax and abdomen and that the number of L3 in the head was maximal at 18.00 hours and minimal at 06.00 hours. When infective mosquitoes were fed on human blood through a Parafilm membrane, 45.2% of the L3 present in the mosquitoes were shed into the blood or on the membrane. All the L3 present in each mosquito migrated to its head during feeding.

VCRC B426, 0.09% emulsifiable concentrate (EC) formulation developed from a metabolite of Pseudomonas fluorescens was tested for efficacy against Culex quinquefasciatus larvae and pupae. At application rates of 100, 200, 300 ml/m2, the formulation caused 100% elimination of larvae and pupae at day 1 after treatments and >80% reduction in pupal density for periods of 7, 12 and 11 days in cesspits and 5, 9 and 10 days in U-shaped drains. In both the habitats, the efficacy of the formulation against pupae was 1.7 times more at 200 ml/m2 than at 100 ml/m2. An increase in dosage to 300 ml/m2 did not improve the efficacy in cesspits but a marginal increase was observed in drains.

The unbundling of the electricity industry has changed the way the energy supply business is handled from a mainly technical to a more commercially dominated one. This new paradigm shift has facilitated creation of new system and/or market operation entities in electrical utilities throughout the world. The increasing number of different companies with diverse interest participating in the electricity supply business leads to a shift from traditional tasks of power system operation among these companies to new additional job duties or even a complete new job as system or market operator. This case study examines the critical change that have taken place in the commercial environment in which power system operators now work both at the system operation level as well as in the generation operation and how that affects their day-to-day operations. This case study analyses the international scenario along with their performance targets that have already been implemented worldwide and would describe their impacts on the job to be performed by the system operator in India. Finally the training needs of system and market operators’ personnel both at the system operation and generation operation where these entities are separated are pointed out, focusing on the new points that have arisen because of the new commercial environment.

A Power system intends to serve the customers as economical as possible with an acceptable degree of reliability and quality. Deterministic methods used in past does not respond nor reflect the probabilistic or stochastic nature of system behavior like customer demands, intermittent nature of renewable energy sources or of component failures. Hence the probabilistic methods get importance while meeting the customer demands with economical investment and acceptable reliability of supply. The determination of system planning reserves is much more complex with the addition of renewable energy sources because of its intermittent nature. In the paper two types of probabilistic methods namely, analytical and Monte Carlo methods are analyzed and are validated with IEEE RTS. The probabilistic nature of the overall wind power of the utility system has been modeled by normal distribution function with standard deviation error for each time interval. The implemented Monte-Carlo simulation method has been applied for one of southern states having high penetration of wind power, to analyze the generation planning after 12th plan (2012–13 to 2016–17).