Multi-Machine Stability Using Dynamic Inversion Technique

Stability studies of multi machine system are a major concern to power system engineers due to the increasing complexity involved. This paper deals with the application of a nonlinear technique called Dynamic Inversion, to TCSC for the improvement of stability of multi-machine system. The transient stability studies for various cases: without any controller, with 75% line compensation and with Dynamic Inversion technique, are compared. The critical clearing time as well as the maximum loading ability is also discussed. The result for the nonlinear controller is found to be better than all the other cases

Application of PST Source based DC Link Restoration for IDVR

Interline Dynamic Voltage Restorer (IDVR) comprises of several Dynamic Voltage Restorers (DVRs) connected to different distribution feeders in the power system sharing common energy storage. One of the DVR provides for voltage sag compensation appearing in that feeder, while the other DVRs restore the energy in the common dc-link thus dynamically maintaining the voltage of DC link capacitor constant by importing power from the other feeders. Restoration of the DC link energy plays an important role in the capability of the individual DVR in the IDVR to mitigate deep sags with long durations. In this paper the restoration of the DC link energy of the IDVR is achieved by the utilizing the phase shifting transformers (PST) which assist the respective DVR during its power control mode. A controlled switching action is provided to choose the appropriate connection of PST to the feeders depending upon the voltage sag condition. The proposed novel concept is examined in a test power system with IDVR

“EVALUATION OF GALPHIMIA GLAUCA STEM METHANOL EXTRACT FRACTIONS FOR ANALGESIC AND ANTI-INFLAMMATORY ACTIVITIES”

Objective: This current investigation assesses in vivo central and peripheral analgesic effects and anti-inflammatory properties of fractions obtained from Galphimia glauca (GG) stem methanol extract. Methods: The laboratory models such as Swiss albino mice and Wistar albino rats were employed in the studies. The GG stem methanol extract was subjected to fractionation with solvents such as hexane, chloroform, ethyl acetate, and methanol. Orally, the dose range of 100, 200, and 400 mg/kg was given for 1 day for evaluating analgesic (hotplate test, tail clip test, writhing test, and formalin test) and weekdays for assessing anti-inflammatory activity (carrageenan and cotton pellet test methods), respectively. The experimental studies were further conducted for determining the involvement of central and peripheral receptor actions in the analgesic activity of the extract by prechallenging it with naloxone and acetic acid, respectively. The in vivo anti-inflammatory studies were conducted using carrageenan-induced rat paw edema model and cotton pellet granuloma test. Results: The LD50 of the extract was found to be >2000 mg/kg b.w. The methanol fraction of 400 mg/kg dose exhibited significant (p≤0.001) and dose-dependent analgesic and anti-inflammatory activity. It also exhibited central and peripheral analgesic actions when treated with naloxone and acetic acid, respectively. Conclusion: The results revealed that the stem methanol fraction has more potential in terms of analgesic and anti-inflammatory properties

High prevalence of subclinical hypothyroidism in pregnant women in South India

Background: Thyroid dysfunction is one of the commonest endocrinopathies seen in pregnancy and affects both maternal and fetal outcomes. There is little data available on its prevalence in Indian pregnant women. This study was conducted at Bhaskar medical college and hospital situated in a rural/suburban area near Hyderabad, Telengana, India. The aim of the study was to find out the prevalence of thyroid disease among pregnant women.  Methods: All consecutive pregnant women registered from January 2014 to December 2014 were included in the study. Morning samples of serum were tested for T3, T4 and TSH.  Results: A total of 1340 women were included in the study. 260 pregnant women (19.41%) had TSH values more than 3.0 mIU/L, the cut-off value used for upper limit of normal in this study. Out of these, 216 had normal T4 value, hence labeled as subclinical hypothyroidism and 44 had low T4, hence termed overt hypothyroidism. Three pregnant women had overt hyperthyroidism and 11 had subclinical hyperthyroidism. Nine women had low T4 values-Isolated hypothyroidism.Conclusions: Prevalence of thyroid disease in pregnancy was found to be higher in our patients, more so the sub clinical hypothyroidism

Optimization of machining characteristics during helical milling of AISI D2 steel considering chip geometry

Helical milling is one of the high-performance and high-quality hole manufacturing activities with strong prospects for the automotive and aerospace industries. Literature suggests chip geometry plays a significant role in optimizing machining operations. In the present study, a mechanistic approach is used to estimate the chip geometry, cutting force and power/energy consumption concerning the tool rotation angle. Experiments are conducted at different levels of spindle rotational speed, cutter orbital speed and axial depth of cuts using 8 and 10 mm diameter mill cutters. Experimental results for cutting speed in X, Y and Z directions are measured. A hybrid approach, which combines the Taguchi method and Graph theory and matrix approach (GTMA) technique is used and optimized process parameters. The highest aggregate utility process parameters are met by 2000 rpm spindle speed, 50 rpm orbital speed and 0.2 mm axial cutting depth during helical milling of AISI D2 steel. FEM simulation is used for predicting the chip thickness, cutting forces and power consumption and also validated the optimization

Trawl fishery of the mid-shelf region off Mangalore coast

Trawl fishery over the mid-shelf region off Mangalore coast was studied during 1979/80,1987/88. Details of craft and gear employed, the nature and extent of fishing ground and the changing pattern of fishins are dealt with. There was an eight-fold increase in fishing effort from 4,132 unit days in 1979•80 to a maximum of 34,758 unit days in 1984•85. The annual production rose from 527 t in 1979-80 to a maximum of 10,327 t in ' 1986-87, showing a twenty-fold increase. The catch rate, however, showed an increasing trend initially reaching a peak value of 299 kg in 1981 -82 and declined thereafter only to register another peak of 335 kg in 1985-86

Fishery, biology and stock assessment of spotted seer, Scomberomorus guttatus (Bloch & Schneider) off Andhra Pradesh

The fishery, biology and stock of the spotted seerfish, Scomberomorus guttatus (Bloch & Schneider) along Andhra Pradesh was studied during 2012-2014. The annual average landing of spotted seer during the period along Andhra coast was 2,614 t. Major contributors were trawlnets-1,104 t (42.2%) and gillnets-950 t (36.3%). Catches were higher during August-December. Length-weight relationship varied significantly between males, females and indeterminates. Growth was isometric in males and allometric in females and indeterminates. Overall sex ratio was 1:1.87. Length at first maturity was 38.9 cm. Peak spawning was observed during November-April. Higher Gonadosomatic index coincided with periods of peak spawning. Mature ovaries contained both maturing (0.41 mm-0.70 mm) and matured (0.71 mm-0.90 mm) ova. von Bertalanffy growth equation was Lt = 71.98 [1-e -0.23 (t + 0.0722)]. Natural mortality, fishing mortality and total mortality were 0.54, 0.49 and 1.03. Exploitation ratio was 0.48. Annual total stocks, biomass and Maximum Sustainable Yield were 8,546 t, 5,335 t and 2,747 t. A minor increase in yield and yield/recruit is possible by increasing the present level of fishing by 20%

Standardisation of RTS beverage from reconstituted cashew apple-based blended juice powder along with Sugandi

Cashew has commercial value for its nut and peduncle (false fruit), known as cashew apple. Requirements of consumers considering convenience, food safety, health benefits and sensory quality have increased demand for fruit juices, but most consumers don’t get time for the ready to use products. Instant juice powders can meet consumer requirements being cheap to transport and with prolonged shelf life. Then the blended juice was mixed with maltodextrin @15 per cent, i.e., 15 g for 100 mL of blended juice by proper homogenisation. The roots of the sugandi (Swallow root - Decalepsis hamiltonii) were collected, cleaned thoroughly and discarded the central white portion of the roots. Among the blended juice treatment combinations, the highest pH of 3.45 was recorded in B3 (75% cashew apple juice + 25% pineapple juice powder at 150°C inlet temperature with a flow rate of 10 mL min-1). The ready-to-serve (RTS) beverage, along with sugandi stored under refrigerated condition, were free from microbial proliferation till the end of the storage period (60th day of storage), indicating its fitness for consumption with maximum flavour, taste and overall acceptability

Genetic structure of the rattan Calamus thwaitesii in core, buffer and peripheral regions of three protected areas in central Western Ghats, India: do protected areas serve as refugia for genetic resources of economically important plants?

Given the increasing anthropogenic pressures on forests, the various protected areas-national parks, sanctuaries, and biosphere reserves-serve as the last footholds for conserving biological diversity. However, because protected areas are often targeted for the conservation of selected species, particularly charismatic animals, concerns have been raised about their effectiveness in conserving nontarget taxa and their genetic resources. In this paper, we evaluate whether protected areas can serve as refugia for genetic resources of economically important plants that are threatened due to extraction pressures. We examine the population structure and genetic diversity of an economically important rattan, Calamus thwaitesii, in the core, buffer and peripheral regions of three protected areas in the central Western Ghats, southern India. Our results indicate that in all the three protected areas, the core and buffer regions maintain a better population structure, as well as higher genetic diversity, than the peripheral regions of the protected area. Thus, despite the escalating pressures of extraction, the protected areas are effective in conserving the genetic resources of rattan. These results underscore the importance of protected areas in conservation of nontarget species and emphasize the need to further strengthen the protected-area network to offer refugia for economically important plant species