FOPDT model and CHR method based control of flywheel energy storage integrated microgrid.

The main causes of frequency instability or oscillations in islanded microgrids are unstable load and varying power output from distributed generating units (DGUs). An important challenge for islanded microgrid systems powered by renewable energy is maintaining frequency stability. To address this issue, a proportional integral derivative (PID) controller is designed in this article. Firstly, islanded microgrid model is constructed by incorporating various DGUs and flywheel energy storage system (FESS). Further, considering first order transfer function of FESS and DGUs, a linearized transfer function is obtained. This transfer function is further approximated into first order plus time delay (FOPTD) form to design PID control strategy, which is efficient and easy to analyze. PID parameters are evaluated using the Chien-Hrones-Reswick (CHR) method for set point tracking and load disturbance rejection for 0% and 20% overshoot. The CHR method for load disturbance rejection for 20% overshoot emerges as the preferred choice over other discussed tuning methods. The effectiveness of the discussed method is demonstrated through frequency analysis and transient responses and also validated through real time simulations. Moreover, tabulated data presenting tuning parameters, time domain specifications and comparative frequency plots, support the validity of the proposed tuning method for PID control design of the presented islanded model.

Fuzzy analytic hierarchy process based generation management for interconnected power system.

Decision makers consistently face the challenge of simultaneously assessing numerous attributes, determining their respective importance, and selecting an appropriate method for calculating their weights. This article addresses the problem of automatic generation control (AGC) in a two area power system (2-APS) by proposing fuzzy analytic hierarchy process (FAHP), an multi-attribute decision-making (MADM) technique, to determine weights for sub-objective functions. The integral-time-absolute-errors (ITAE) of tie-line power fluctuation, frequency deviations and area control errors, are defined as the sub-objectives. Each of these is given a weight by the FAHP method, which then combines them into an single final objective function. This objective function is then used to design a PID controller. To improve the optimization of the objective function, the Jaya optimization algorithm (JOA) is used in conjunction with other optimization techniques such as sine cosine algorithm (SCA), Luus-Jaakola algorithm (LJA), Nelder-Mead simplex algorithm (NMSA), symbiotic organism search algorithm (SOSA) and elephant herding optimization algorithm (EHOA). Six distinct experimental cases are conducted to evaluate the controller's performance under various load conditions, with data plotted to show responses corresponding to fluctuations in frequency and tie-line exchange. Furthermore, statistical analysis is performed to gain a better understanding of the effectiveness of the JOA-based PID controller. For non-parametric evaluation, Friedman rank test is also used to validate the performance of the proposed JOA-based controller.

Investigation of rank order centroid method for optimal generation control.

Multi-criteria decision-making (MCDM) presents a significant challenge in decision-making processes, aiming to ascertain optimal choice by considering multiple criteria. This paper proposes rank order centroid (ROC) method, MCDM technique, to determine weights for sub-objective functions, specifically, addressing issue of automatic generation control (AGC) within two area interconnected power system (TAIPS). The sub-objective functions include integral time absolute errors (ITAE) for frequency deviations and control errors in both areas, along with ITAE of fluctuation in tie-line power. These are integrated into an overall objective function, with ROC method systematically assigning weights to each sub-objective. Subsequently, a PID controller is designed based on this objective function. To further optimize objective function, Jaya optimization algorithm (JOA) is implemented, alongside other optimization algorithms such as teacher-learner based optimization algorithm (TLBOA), Luus-Jaakola algorithm (LJA), Nelder-Mead simplex algorithm (NMSA), elephant herding optimization algorithm (EHOA), and differential evolution algorithm (DEA). Six distinct case analyses are conducted to evaluate controller's performance under various load conditions, plotting data to illustrate responses to frequency and tie-line exchange fluctuations. Additionally, statistical analysis is performed to provide further insights into efficacy of JOA-based PID controller. Furthermore, to prove the efficacy of JOA-based proposed controller through non-parametric test, Friedman rank test is utilized.

Evaluation of health status of horses immunized with snake venom and montanide adjuvants, IMS 3012 (nanoparticle), ISA 206 and ISA 35 (emulsion based) during polyvalent snake antivenom production: hematological and biochemical assessment.

Several biochemical and hematological changes in horses are observed during production of snake antivenom. Although conventional adjuvants like Freund's (Complete and Incomplete) are good immunopotentiators, they produce considerable local reactions in animals. Variety of commercial adjuvants, like montanide adjuvants, having high immunopotentiation and showing lesser side effects are available. The prime objective during antivenom production is to strike a balance between safety of immunized horses and efficacy of the product. In our earlier work, efficacy of montanide group of adjuvants in antivenom production has already been established. The aim of the present work was to assess the safety parameters in horses, viz.: biochemical and hematological, during production of snake antivenom. In the present study, 33 new horses were randomly divided into four groups and hyperimmunized using mixture of snake venoms, viz.: Cobra venom, Russell's viper venom, Krait venom and Echis venom along with montanide adjuvants, IMS 3012, ISA 206, ISA 35 and Incomplete Freund's adjuvant as a control adjuvant; through subcutaneous route at intervals of two weeks. During the immunization period, biochemical and hematological parameters were monitored at 0th, 14th, 21st, 30th and 42nd weeks. The mean hemoglobin values dropped slightly during initial immunization but subsequently regained to normal levels. The mean serum total protein values and globulin levels showed an increment in all the four groups, compared to day zero, vice-versa a slight drop was observed in albumin levels. No significant changes were observed in serum creatinine, bilirubin, alkaline phosphatase and blood urea nitrogen values. Finally, we conclude that montanide adjuvants could be a safer alternative to the conventional adjuvants for primary phase of immunization in antivenom production.

Production of high titre antibody response against Russell's viper venom in mice immunized with ethanolic extract of fruits of Piper longum L. (Piperaceae) and piperine.

Piper longum L. fruits have been traditionally used against snakebites in north-eastern and southern region of India. The aim of the study was to assess the production of antibody response against Russell's viper venom in mice after prophylactic immunization with ethanolic extract of fruits of Piper longum L. and piperine. The mice sera were tested for the presence of antibodies against Russell's viper venom by in vitro lethality neutralization assay and in vivo lethality neutralization assay. Polyvalent anti-snake venom serum (antivenom) manufactured by Haffkine Bio-Pharmaceutical Corporation Ltd. was used as standard. Further confirmation of presence of antibodies against the venom in sera of mice immunized with PLE and piperine was done using indirect enzyme-linked immunosorbent assay (ELISA) and double immunodiffusion test. Treatment with PLE-treated mice serum and piperine-treated mice serum was found to inhibit the lethal action of venom both in the in vitro lethality neutralization assay and in vivo lethality neutralization assay. ELISA testing indicated that there were significantly high (p<0.01) levels of cross reactions between the PLE and piperine treated mice serum and the venom antigens. In double immunodiffusion test, a white band was observed between the two wells of antigen and antibodies for both the PLE-treated and piperine-treated mice serum. Thus it can be concluded that immunization with ethanolic extract of fruits of Piper longum and piperine produced a high titre antibody response against Russell's viper venom in mice. The antibodies against PLE and piperine could be useful in antivenom therapy of Russell's viper bites. PLE and piperine may also have a potential interest in view of the development of antivenom formulations used as antidote against snake bites.

Anti-snake venom activities of ethanolic extract of fruits of Piper longum L. (Piperaceae) against Russell's viper venom: characterization of piperine as active principle.

ETHNOPHARMACOLOGICAL RELEVANCE: Piper longum L. fruits have been traditionally used against snakebites in north-eastern and southern region of India. AIM OF THE STUDY: To examine the ability of ethanolic extract of fruits of Piper longum L., Piperaceae (PLE) and piperine, one of the main active principles of Piper longum, to inhibit the Russell's viper (Doboia russelii, Viperidae) snake venom activities. MATERIALS AND METHODS: Anti-snake venom activities of ethanolic extract of fruits of Piper longum L. (Piperaceae) and piperine against Russell's viper venom was studied in embryonated fertile chicken eggs, mice and rats by using various models as follows: inhibition of venom lethal action, inhibition of venom haemorrhagic action (in vitro), inhibition of venom haemorrhagic action (in vivo), inhibition of venom necrotizing action, inhibition of venom defibrinogenating action, inhibition of venom induced paw edema, inhibition of venom induced mast cell degranulation, creatine kinase assay and assay for catalase activity. RESULTS: PLE was found to inhibit the venom induced haemorrhage in embryonated fertile chicken eggs. Administration of PLE and piperine significantly (p<0.01) inhibited venom induced lethality, haemorrhage, necrosis, defibrinogenation and inflammatory paw edema in mice in a dose dependent manner. PLE and piperine also significantly (p<0.01) reduced venom induced mast cell degranulation in rats. Venom induced decrease in catalase enzyme levels in mice kidney tissue and increase in creatine kinase enzyme levels in mice serum were significantly (p<0.01) reversed by administration of both PLE and piperine. CONCLUSIONS: PLE possesses good anti-snake venom properties and piperine is one of the compounds responsible for the effective venom neutralizing ability of the plant.

The action of red scorpion (Mesobuthus tamulus coconsis, pocock) venom and its isolated protein fractions on blood sodium levels

Red scorpion (Mesobuthus tamulus or Buthus tamulus) venom samples were collected at different regions of India: western (Chiplun and Ahmednagar from Maharashtra State) and southern (Ratnagiri and Chennai from Tamil Nadu State). The action of whole venoms on the blood sodium levels of mice was assessed using flame photometry. Seven peptides were common to all venom samples. They were separated using the native polyacrylamide gel electrophoresis (PAGE) technique and their activities were also studied using flame photometry. There was a decrease in the concentration of sodium ions in the serum, which suggested the blockage of such ions by scorpion venom toxins. Among the 10 protein bands isolated, the band at 79.6 kDa presented maximum activity in decreasing serum sodium ions concentration. Whole venom from Chiplun region also showed maximum activity. The western blotting technique demonstrated that the anti-scorpion venom sera produced by Haffkine Biopharmaceuticals Corporation Ltd., India, neutralized all four venom samples.(AU)

Intraspecific variation in protein pattern of red scorpion (Mesobuthus tamulus, coconsis, pocock) venoms from Western and Southern India

Red scorpions Mesobuthus tamulus (Coconsis, Pocock) were obtained from different regions of West and South India (Ratnagiri, Chiplun and Ahmednagar from Maharashtra and Chennai from Tamil Nadu, respectively). Their venoms composition was analyzed using gel electrophoresis (SDS-PAGE). All venom samples shared six bands of 170, 80, 60, 57, 43, and 38 kDa molecular weights. Bands of 115 kDa and 51.5 kDa were characteristic of venoms obtained from red scorpions of Chiplun region, and the 26kDa band was absent in scorpion venom from Tamil Nadu. The separated protein band patterns suggest that the venoms from Ratnagiri, Ahmednagar and Tamil Nadu had high similarities in their biochemical composition but differed from that of Chiplun region. These data were also supported by the Jaccard (J) index. The J value was 0.33 for venom obtained from Ratnagiri-Ahmednagar, 0.31 for venom from Ratnagiri-Tamil Nadu, and 0.3 for venom from Ratnagiri-Chiplun region. This suggests the existence of genetic variation among the different strains of red scorpion in western and southern India. The antiserum produced by Haffkine Biopharmaceuticals Corporation Ltd. completely neutralized proteins of venoms from all the regions studied.(AU)