32 research outputs found
PLATE 1 in A new species of Isonychia Eaton, 1871 (Ephemeroptera: Isonychiidae) from Kapila River, Central Western Ghats, India
No full textPLATE 1. Figure (1) Male imago of Isonychia radhae n. sp.Published as part of Muthukatturaja, M., Balasubramanian, C., Rathinakumar, T. & Sivaramakrishnan, K. G., 2021, A new species of Isonychia Eaton, 1871 (Ephemeroptera: Isonychiidae) from Kapila River, Central Western Ghats, India, pp. 283-291 in Zootaxa 4908 (2) on page 285, DOI: 10.11646/zootaxa.4908.2.9, http://zenodo.org/record/443845
Male Chemical Signalling to Recruit Females in the Greater Short-Nosed Fruit Bat Cynopterus sphinx
No full textRathinakumar A, Baheerathan M, Caspers B, et al. Male Chemical Signalling to Recruit Females in the Greater Short-Nosed Fruit Bat Cynopterus sphinx. Acta Chiropterologica. 2021;23(1)
Effect of hydraulic and geometrical properties on stepped cascade aeration system
No full textStepped cascade aeration system is commonly used to aerate the water and
wastewater to increase the dissolved oxygen during pre and post treatment
process. In the present research, experiments were conducted to evaluate
the performance of a rectangular Cascade Aeration System with varying
flow rates, risers and tread by maintaining constant width of the channel
using water collected from reverse osmosis plant. The experiments were
carried out with four different risers such as 0.15 m, 0.18 m, 0.225 m and
0.30 m. Each rise was investigated with five different tread of 0.60 m, 0.55
m, 0.50 m, 0.45 m and 0.40 m. Comprehensive experimental investigations
were carried out for different hydraulic loading rates of 0.005 to 0.035
m
3
/s/m2
. Results obtained from the experiments reveals that increasing
dimensionless discharges promotes more aeration, attains a maximum up to
dimensionless discharge= 2.22 and beyond this there was a significant
decrease in aeration. In addition, the increased in number of steps
significantly enhances air entertainment and surface fall rate in the Stepped
Cascade Aeration System. A regression equation was derived by keeping
aeration efficiency as response with dimensionless discharge and oxygen
saturation concentration as influencing parameters. The dimension less
discharge is a function of critical depth of the rectangular channel and step
height, whereas oxygen saturation concentration represents the ratio of
oxygen deficit and oxygen saturation concentration. Based on the
experimental results, the optimum design and/or results such as number of
steps (12 numbers) and hydraulic loading rate (0.025 m3
/s/m2
) with fixed
tread width of 0.6 m were identified to achieve maximum aeration rate
(0.5-0.60) in Aeration system
Investigation on Voltage Stability and Analysis of a Dynamic Power System Using Bifurcation Techniques
No full textComparative Study of Various Adjustable Speed Drives During Voltage Sag
Get PDFThis Paper compares the sensitivity of various adjustable speed drives to voltage sag for the process control applications. Three phase voltage sag of type B caused due to SLG fault is considered and four topologies of ASD’s are compared in this paper. The comparison is done especially in speed, voltage, current and torque of the ASDs. Diode rectifier without z source inverter, diode rectifier with z source inverter , single phase two leg Vienna rectifier and single phase neutral linked Vienna with z source inverter are compared and the best one is highlighted. The circuits of various ASD’s are simulated using Matlab /Simulink.
A Comparative Study of Inverters for Three Phase Induction Motor Drives to Mitigate Voltage Sag
No full textFractional Order PID Controlled PV Buck Boost Converter with Coupled Inductor
Get PDFBuck-boost converter is a good interface between PV and the load. This paper deals with comparison between PI and FOPID controlled PV fed Buck Boost Converter with Coupled Inductor (PVBBCCI) systems. Open loop PVBBCCI system, closed loop PI controlled PVBBCCI and FOPID based PVBBCCI systems are designed, modeled and simulated using Simulink and their results are presented. The investigations indicate the superior performance of FOPID controlled PVBBCCI system. The proposed system has advantages like reduced hardware count enhanced dynamic response and improved stability
Comparison of Sine and Space Vector Modulated Embedded Z-source Inverter fed Three Phase Induction Motor Drive System
Get PDFThis paper deals with performance of photovoltaic powered Embedded Z-Source Inverter (EZSI) fed Induction motor drive. The DC output from the PV-Panel is boosted and converted into AC using Embedded Z-Source Inverter. EZSI system based on the concept of Z-Source Inverter (ZSI), which provides single stage power conversion. The EZSI also produce same voltage gain as that of the ZSI based system. In EZSI the DC source is embedded within the X-shaped LC impedance network, due to this EZSI has the added advantage of inherent source filtering capability , this can be achieved without any extra passive filter. EZSI can produce the AC output voltage which is greater than the DC link voltage. EZSI system also provides ride-through capability under voltage sags. In this paper the performance of space vector modulated EZSI fed Induction Motor Drive is compared with sinusoidal PWM controlled EZSI fed Drive system. The PV powered EZSI fed three phase Induction Motor System is designed, modeled and simulated using MAT LAB-SIMULINK and the corresponding results are presented. This drive system has advantages like voltage boosting ability and reduced harmonic content
A DC Inrush Current Minimisation Method using Modified Z-source Inverter in Adjustable Speed Drives
No full textThe adjustable speed drives employ PWM converter – inverter system in order to obtain unity power factor.The DC inrush current in DC link capacitors of the rectifier limits the operation of power devices.Hence, this paper proposes a new approach to reduce the DC inrush current by employing modified Z-source inverter in a Adjustable Speed Drive system. The operating principles, design procedure and simulation results are shown and compared with the conventional Z-Source inverter
