Development and validation of enhanced fuzzy logic controller and boost converter topologies for a single phase grid system

Introduction. Solar photovoltaic system is one of the most essential and demanding renewable energy source in the current days, due to the benefits of high efficiency, reduced cost, no pollution, and environment friendly characteristics. Here, the maximum power point tracking controller has been implemented for obtaining an extreme power from the photovoltaic array. For this purpose, there are different controller and converter strategies have been deployed in the conventional works. It includes perturb and observation, incremental conductance, fuzzy logic systems, and hill climbing, and these techniques intend to extract the high amount of power from the solar systems under different climatic conditions. Still, it limits with the issues like increased design complexity, high cost consumption, high harmonics, and increased time consumption. The goal of this work is to deploy an improved controlling and converter topologies to regulate the output voltage and power fed to the single phase grid systems. The novelty of the work aims to develop an enhanced fuzzy logic controller based maximum power point tracking mechanism with the boost DC-DC converter topology for a single phase grid tied photovoltaic systems. Practical value. Also, the higher order harmonics suppression and unbalanced current elimination are handled by the use of LCL filtering technique, which efficiently reduces the harmonics in the output of inverter voltage and current. Moreover, it helps to obtain the reduced total harmonics distortion value with improved accuracy and efficiency. Results. There are different performance indicators have been evaluated for validating the proposed enhanced fuzzy logic controller–maximum power point tracking controlling technique. Moreover, the obtained results are compared with some of the conventional controlling algorithms for proving the betterment of the proposed work.Вступ. Сонячна фотоелектрична система є одним з найбільш важливих та затребуваних відновлюваних джерел енергії в наші дні завдяки перевагам високої ефективності, низької вартості, відсутності забруднення та екологічно безпечним характеристикам. При цьому було реалізовано контролер стеження за точкою максимальної потужності для отримання екстремальної потужності від фотогальванічної батареї. З цією метою у традиційних роботах використовуються різні стратегії контролерів та перетворювачів. Це включає збурення та спостереження, інкрементну провідність, системи нечіткої логіки та сходження на пагорб, і ці методи призначені для отримання великої кількості енергії із сонячних систем у різних кліматичних умовах. Тим не менш, це обмежується такими проблемами, як підвищена складність конструкції, високі витрати, високі гармоніки та збільшення витрат часу. Метою цієї роботи є розвиток вдосконаленого управління та топології перетворювача для регулювання вихідної напруги та потужності, що подається до однофазних мережевих систем. Новизна роботи спрямована на розробку вдосконаленого механізму відстеження точки максимальної потужності на основі контролера з нечіткою логікою з топологією перетворювача постійного струму, що підвищує, для однофазних фотоелектричних систем, прив'язаних до мережі. Практична цінність. Крім того, придушення гармонік вищих порядків та усунення незбалансованого струму здійснюється за допомогою методу LCL-фільтрації, який ефективно зменшує гармоніку на виході інвертора напруги та струму. Крім того, це допомагає отримати зменшене значення повного гармонійного спотворення з покращеною точністю та ефективністю. Результати. Існують різні показники ефективності, які були оцінені для перевірки запропонованого покращеного контролера нечіткої логіки – методу керування відстеженням точки максимальної потужності. Крім того, отримані результати порівнюються з деякими звичайними алгоритмами контролю для доведення кращості запропонованої роботи

Isolation, Characterization, and RP-HPLC Estimation of P-Coumaric Acid from Methanolic Extract of Durva Grass (Cynodon dactylon Linn.) (Pers.)

P-coumaric acid is a nonflavonoid phenolic acid and is a major constituent of the species Cynodon dactylon Linn. (Pers.). In this study isolation of P-coumaric acid was achieved by preparative TLC and the compound thus isolated was characterised by UV, mass, and H 1 NMR spectral analysis. An isocratic RP-HPLC method was developed for the estimation of P-coumaric acid from methanolic extracts of durva grass. The chromatographic separations were achieved by RP-C 18 column (250 mm × 4.6 mm, 5 ), Shimadzu LC-20AT Prominence liquid chromatograph, and a mobile phase composed of water : methanol : glacial acetic acid (65 : 34 : 1 v/v). The flow rate was 1.0 mL/min and the analyses of column effluents were performed using UV-visible detector at 310 nm. Retention time of P-coumaric acid was found to be 6.617 min. This method has obeyed linearity over the concentration range of 2-10 g/mL and the regression coefficient obtained from linearity plot for P-coumaric acid was found to be 0.999. RP-HPLC method was validated in pursuance of ICH guidelines

INTERNATIONAL JOURNAL OF INSTITUTIONAL PHARMACY AND LIFE SCIENCES QUANTITATIVE ESTIMATION OF RAFOXANIDE IN POWDER FOR SUSPENSION BY SPECTROPHOTOMETRIC METHODS

ABSTRACT Two simple, rapid, cost effective spectrophotometric methods have been developed for the determination of Rafoxanide in its bulk form as well as pharmaceutical dosage form. Method M 1 is based on measurement of absorbance at its absorption maximum at about 280nm against a methanol solution as a blank. Method M 2 is based on oxidation of the drug followed by complexation with 2,2'-bipyridyl reagent to give blood red colored coordination complex which has shown maximum absorbance at the maximum at about 520 nm against its reagent blank. These methods were found linear within the concentration range of 5-25μg/ml and 4-28μg/ml for Method M 1 and Method M 2 respectively. The proposed methods show correlation coefficient of >0.999 for the given concentration ranges. These methods were validated according to ICH guidelines and the result of estimation of marketed powder formulation was found to be 99.50% and 99.77% for Method M 1 and Method M 2 respectively with their %RSD of precision less than 2

Development of RP-HPLC Method for the Simultaneous Quantitation of Levamisole and Albendazole: Application to Assay Validation

A reverse phase high-performance liquid chromatographic (RP-HPLC) method was developed and validated for simultaneous estimation of levamisole and albendazole in drug substance and in its combinational dosage form. The analysis was carried out using Inertsil ODS C18 (4.6 x 150 mm, 5 μm) column, and the separation was carried out using a mobile phase containing a buffer of pH 3.5 and acetonitrile (70:30 v/v) pumped at a flow rate of 1.0 mL/min with variable wavelength UV-detection at 224 nm. Both the drugs were well resolved in the stationary phase and the retention times were 2.350 min and 4.055 for levamisole and albendazole, respectively. The method was validated and shown to be linear in the concentration range of 15-45μg/ml and 40-120μg/ml for levamisole and albendazole, respectively. The limit of detection (LOD) and limit of quantification (LOQ) were determined based on standard deviation of the y-intercept and the slope of the calibration curve. LOD and LOQ values were 2.08μg/ml and 6.03μg/ml for levamisole and 3.15μg/ml and 10.40μg/ml for albendazole, respectively. The accuracy of the method was assessed by adding known amount of standard solution (75 %, 100 %, and 125% of the sample concentration) to the preanalyzed sample solution of 100% concentration. All the samples were prepared and analyzed in triplicate. The percentage mean recovery by standard addition experiments of levamisole and albendazole is 99.66% and 98.73%, respectively

Towards scale-up and regulatory shelf-stability testing of curcumin encapsulated polyester nanoparticles

This study reports scale-up and shelf-stability of curcumin encapsulated poly(lactic acid-co-glycolic acid) (PLGA) nanoparticles. The curcumin encapsulated PLGA nanoparticles were prepared by emulsification solvent evaporation/diffusion, and large quantities were made by varying the homogenisation time (5, 15 and 30 min). The particle size decreased as the homogenisation duration increased from 5 to 30 min, and the particles were spherical as confirmed by atomic force microscopy. For the large-scale preparations, the mean particles size was found to be 288.7 ± 3.4 (polydispersity index 0.15 ± 0.01) with curcumin entrapment 52.5 ± 4.3 %, which were comparable to the lab-scale preparations. The curcumin encapsulated nanoparticles were freeze-dried using sucrose (5 %, w/v) as a cryoprotectant. The freeze-dried nanoparticles were subjected to 6-month stability study as per the International Conference on Harmonisation guideline at room temperature and refrigerated storage conditions. Intermediate sampling was done (monthly), and the nanoparticles were thoroughly characterised for particle size, entrapment efficiency, surface morphology and crystallinity, which were compared to fresh preparations. The curcumin encapsulated PLGA nanoparticles were found to be stable at refrigerated as well as room temperature storage test conditions indicated by their particle characteristics. X-ray diffraction results confirm amorphous nature of curcumin on nano-encapsulation that stays intact after freeze drying and 6-month stability testing. Together these data offer possibility of producing large quantities of polymer nanoparticles that are suitable for room as well as refrigerated storage conditions opening up possibilities to conduct repeated dosings in a chronic setting or regulatory toxicology studies of such nanomedicines

Isolation, Characterization, and RP-HPLC Estimation of P-Coumaric Acid from Methanolic Extract of Durva Grass ( Cynodon dactylon

P-coumaric acid is a nonflavonoid phenolic acid and is a major constituent of the species Cynodon dactylon Linn. (Pers.). In this study isolation of P-coumaric acid was achieved by preparative TLC and the compound thus isolated was characterised by UV, mass, and H1 NMR spectral analysis. An isocratic RP-HPLC method was developed for the estimation of P-coumaric acid from methanolic extracts of durva grass. The chromatographic separations were achieved by RP-C18 column (250 mm × 4.6 mm, 5 μ), Shimadzu LC-20AT Prominence liquid chromatograph, and a mobile phase composed of water : methanol : glacial acetic acid (65 : 34 : 1 v/v). The flow rate was 1.0 mL/min and the analyses of column effluents were performed using UV-visible detector at 310 nm. Retention time of P-coumaric acid was found to be 6.617 min. This method has obeyed linearity over the concentration range of 2–10 μg/mL and the regression coefficient obtained from linearity plot for P-coumaric acid was found to be 0.999. RP-HPLC method was validated in pursuance of ICH guidelines

ACUTE TOXICITY TESTING OF NEWLY DISCOVERED POTENTIAL ANTIHEPATITIS B VIRUS AGENTS OF PLANT ORIGIN

Objective: Our previous studies indicate that alkaloids could be developed as potential antihepatitis B agents. In the present study, we investigated the in vitro antihepatitis B virus (HBV) activity and in vivo acute oral toxicity of three isoquinoline alkaloids [-(-) Canadine, Corydadine, and Berberine] obtained from Fumaria and Corydalis species. The compounds were selected based on their therapeutic indexes calculated previously in vitro.Methods: The antiviral activity and cytotoxicity of selected isoquinoline alkaloids were evaluated in vitro in HepG2 cells. In vivo, acute oral toxicity was performed in female mice following the Organization for Economic Cooperation and Development test guideline-423 (acute toxicity class method).Results: The selected agents have shown high antiviral activity against HBV and low cytotoxicity in vitro. The results obtained from an acute oral toxicity study revealed that the LD50 of all the test compounds was >2000 mg/kg when administered orally to mice. All the tested compounds fall under the category 5 (unclassified) according to the Globally Harmonized System, with a LD50 value >2000 mg/kg when orally administered to mice.Conclusion: The results of the study revealed that OR-13 and MNAD can be studied further and can be developed as antihepatitis B drugs