Control System By Smarajit Ghosh Pdf Download
Itxaso Mariyo
The efficient speed controller is found to be an important requirement to run the motor for the brushless direct current (BLDC) motor. This requirement is considered as superior, as it may increase the operating speed and system efficiency. In the existing methods, proportional plus integral (PI) controller has been included because of its simple architecture. But the PI controller produces load disturbance, control complexity and some parametric (Proportional plus integral) variations. The purpose of this proposed controller is to overcome the problems produced by PI controller in BLDC motor.
The proposed BLDC motor is developed with fixed order H-infinity controller. In this architecture, both the weight functions and transfer functions were included to design the controller. This controller has been included in this BLDC to detect the rotor position. The optimal position of rotor is identified by introducing particle swarm optimization algorithm.
The performance of the torque, speed and back electro-motive force is analysed and compared with the existing controllers such as fuzzy proportional plus integral plus derivative, sensing algorithm and fuzzy proportional plus derivative controller.
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Traditional leavened wheat-based flat bread khambir is a staple food for the high-altitude people of the Western Himalayan region. The health promoting abilities of two types of khambir, yeast added khambir (YAK) and buttermilk added khambir (BAK), were evaluated. A group of microbes like yeast, mold, lactic acid bacteria (LAB), and Bifidobacterium sp. were abundant in both khambir but in varied proportions. Both are enriched with phenolics and flavonoids. The aqueous extracts of both breads strongly inhibited the growth of enteropathogens. Molecular docking experiments showed that phenolic acid, particularly p-coumaric acid, blocked the active sites of β-glucosidase and acetylcholine esterase (AChE), thereby inhibiting their activities. YAK and BAK showed antiradical and antioxidant activity ranging from 46 to 67% evaluated using 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS), and ferric reducing/antioxidant power (FRAP) assays. The aqueous extract of both khambir samples protected the arsenic toxicity when examined under an in situ rat intestinal loop model study. The arsenic induced elevated levels of superoxide dismutase (SOD), catalase (CAT), reduced glutathione, lipid peroxidation (LPO) and DNA fragmentation, and transmembrane mitochondrial potential was alleviated by khambir extract. These results scientifically supported its age-old health benefit claims by the consumer at high altitude and there are enough potentialities to explore khambir as a medicinal food for human welfare.
Traditional fermented foods have greater preference in certain communities due to typical characteristics such as flavor, color, and texture (Mondal et al., 2016). Most of the fermented foods contain an increased amount of health beneficial nutraceuticals, bioactive components, and good microbes compared to their unfermented substrate (Tamang et al., 2016). Due to age-old safety and beneficial experiences, scientists have been focused on exploring their nutrient profile, wild microbial resources, and therapeutic components, standardizing process parameters for the welfare of mankind.
Traditional process of khambir preparation. After overnight incubation of wheat flour and starter (yeast or buttermilk), the fermented dough is divided, and ball shaped by hand (A). The handmade round-shaped dough is baked over a hot stone and then under direct fire (B). The final cleaned and polished brown bread is ready for consumption (C).
Although the native people believe in the health benefits of khambir, surprisingly no such study has been conducted to validate this. Considering this, we examined the health benefits (antimicrobial, trypsin, acetylcholine, and β-glucosidase inhibitory activities, antioxidant, and detoxicant activity) of homemade Tagi Khambir. Moreover, the ameliorative role of its extract was tested against arsenic (a globally recognized environmental pollutant and Gr. A carcinogen) induced toxicity, in an in situ loop model study of rat intestine, to prove its detoxification activity.
Khambir samples were collected from households in two villages (Sabu and Pheyang which are about 10 km away from the town of Leh) in the Leh district, Jammu and Kashmir state, India. Three types of preparation, viz., standard white wheat bread (unfermented, used as control), yeast (marketed Baking yeast) added khambir (YAK), and buttermilk added khambir (BAK) were collected. Then the samples were transferred into a sterile container and transported to the laboratory through an ice box. Bread samples were dried in a food dryer at 55C for 10 h, and then dissolved into sterile distilled water (0.1%, w/v) by homogenization and centrifuged at 2000 g for 10 min. The supernatant was used as a food extract for further studies.
The quantity of the prevalent group of microbes in the food samples (direct sample) was enumerated on the basis of colony-forming units (cfu). The counts of different bacterial group were performed based on their colony morphology and color in various selective and differential agar media. Briefly, 10 g of the raw sample was mixed with a 100 ml of phosphate buffer saline (pH 7.2) and used as stock for the microbial count. The group of lactic acid bacteria (LAB) and Bifidobacterium sp. were cultivated in Rogosa SL agar (supplemented with 0.132% acetic acid) and Bifidobacterium agar supplemented with Bifidobacterium Selective Supplement (HiMedia, FD285), respectively, and plates were incubated in a CO2 incubator (5% CO2), at 37C (Adak et al., 2013). All of the luxuriant growing colonies were enumerated for the above-mentioned bacteria. Total aerobic bacteria were quantified using Plate Count Agar (PCA) media and incubated at 37C (Adak et al., 2013). Yeast and mold were enumerated by using yeast and mold agar, and Potato Dextrose Agar (PDA) media, respectively, and incubated at 30C. The mycelial and round convex colonies were recorded for the mold and yeast counts, respectively. MacConkey agar and Salmonella differential agar were used for the determination of Escherichia coli and Salmonella sp., respectively. The plates were incubated at 35C for 24 to 48 h. The pink red with bile precipitated colonies grown on the MacConkey agar were enumerated for E. coli. Moreover, the colorless and pink red colonies were counted for Salmonella sp. For Vibrio sp. enumeration, the yellow and bluish green color colonies grown on Thiosulfate Citrate Bile salt Sucrose (TCBS) agar base were selected.
The samples (300 mg) were extracted with 3 ml of methanol/water (80/20, v/v), for 10 min by sonication at room temperature. After centrifugation at 8000 rpm for 5 min, the supernatant was removed, and the extraction was repeated two times in a similar way. The combined supernatants were evaporated to dryness by centrifugal evaporation. The residues were dissolved in 400 μl of methanol/water (80/20, v/v) and filtered through a 0.2 μm PTFE membrane filter. A 20 μl of the final solution was injected into the HPLC system.
The bread sample was mixed with 10% diaion HP 20 resin (Sigma) under shaking for 30 min on a magnetic stirrer. Then the flask contents were eluted with 20 ml methanol. The collected methanol fractions were evaporated in a rotary evaporator (EYELA, Japan) and the residue was dissolved in DMSO and stored at -20C for further analysis.
The alteration of mitochondrial membrane potential of intestinal epithelial cells of different treatment was measured spectrofluorometrically using Rhodamine 123 (Dash et al., 2014). Cells were seeded in six-well plates at a density of around 2 104/well and incubated with 10 μl of 1.5 μM Rhodamine 123 at 37C in the dark for 30 min. Then, fluorescence emitting from the Rh123 was measured for 2 min in a fluorescence spectrophotometer (Hitachi F-7000). The mitochondrial membrane potential was expressed as an emitting fluorescence level at an excitation wavelength of 493 nm and an emission wavelength of 522 nm.
Collected data were presented as the arithmetic mean (mean SD). The variations in different analysis results were examined by one-way ANOVA [least significant difference (LSD) testing]. A significant variation was accepted at the level of 5 and 1% (i.e., p< 0.05 and p< 0.01) was measured using Sigmastat 11.0 (United States) statistical software. Multiple correlations between the beneficial properties of the control, YAK, and BAK were performed by IBM-SPSS (version 19).
India is a country which has not lost all of its culture, food habits, and traditions. Most ethnic people still prefer traditional food as a staple diet and these foods are commonly served to celebrate functions, marriages, and rituals. Khambir is a traditional flat bread prepared and consumed in the Ladhak region. The native people believe that it plays a health protective role in this extreme environment. However, this claim has not been scientifically validated thus far. Considering this, we evaluated its functional properties to justify its age-old health benefit claims at high altitudes.
The antimicrobial activity of the aqueous extracts of khambir samples was tested against different strains of enteropathogens and other organisms (Table 3). It was found that YAK exerted more strain specific antibiosis, particularly against enteropathogens like S. typhi, S. dysenteriae, S. faecalis, and V. harveyi than BAK. The YAK also showed significant inhibitory effects against S. aureus, whereas the killing effect of BAK was more prominent against M. luteus. The results indicated that the reactive metabolites that evolved during fermentation act as a natural preservative in this food. The strain specific and variable antimicrobial effect of natural medicines is a common phenomenon and many factors like pH, extracting solvent and techniques, dilution, culturing media, and source of microorganism are very important and can alter the interaction of the active ingredients with medicinal flora (Rios and Recio, 2005). The antibiosis of the tested food samples was very significant and comparable with commercial antibiotics like tetracycline, which is commonly used as a food preservative (Table 3).
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