Anxiolytic effect of leaf galls extracts of Pipernigrum Linn. in Swiss Albino mice

Rajesh Rajamani,Sathiyanarayanan L,Arulmozhi S,Ruby 경희대학교 융합한의과학연구소 2009 Oriental Pharmacy and Experimental Medicine Vol.9 No.2

Anxiety disorders are one of the serious problems which need proper therapy devoid of side effects of presently available medicines. The present study evaluates the anxiolytic and sedative activity of leaf galls of Piper nigrum Linn. in Swiss Albino mice. The pet. ether, chloroform, ethyl acetate and ethanol extracts of leaf galls of Piper nigrum Linn were obtained by continuous soxhlet extraction. The prepared extracts were found to be safe up to 2000 mg/kg body weight of mice in the acute toxicity study. Each extract was assessed for anxiolytic activity in Swiss Albino mice by elevated plus Maze, open field test, rota rod test and phenobarbitone induced sleeping time test. In the Elevated Plus Maze test, the pet.ether extract and chloroform extract at a dose of 50 mg/kg b.w. orally, significantly (P < 0.01) increased the number of entries and time spent in open arm comparable with standard diazepam at the dose of 10 mg/kg. b.w. p.o. In the open field test, pet. ether extract (50 mg/kg b.w. p.o.) showed significant increase (P < 0.01) in ambulation and activity in the center. Chloroform extract (50 mg/kg b.w p.o.) was significant (P < 0.05) for both ambulation and center activity. Pet. ether extract (50 mg/kg b.w. p.o) also showed significant activity (P < 0.01) in rota rod test. All the results are comparable with standard diazepam at the dose of 1 mg /kg b.w, p.o. Moreover all the extracts showed significant (P < 0.01) increase in the phenobarbitone induced sleeping time among which pet.ether showed more prominent activity (36%) comparable with control. The results revealed that, the active pet.ether extract and chloroform extract of leaf galls of Piper nigrum Linn is worthwhile to develop the bioactive principle for anxiolytic activity. Anxiety disorders are one of the serious problems which need proper therapy devoid of side effects of presently available medicines. The present study evaluates the anxiolytic and sedative activity of leaf galls of Piper nigrum Linn. in Swiss Albino mice. The pet. ether, chloroform, ethyl acetate and ethanol extracts of leaf galls of Piper nigrum Linn were obtained by continuous soxhlet extraction. The prepared extracts were found to be safe up to 2000 mg/kg body weight of mice in the acute toxicity study. Each extract was assessed for anxiolytic activity in Swiss Albino mice by elevated plus Maze, open field test, rota rod test and phenobarbitone induced sleeping time test. In the Elevated Plus Maze test, the pet.ether extract and chloroform extract at a dose of 50 mg/kg b.w. orally, significantly (P < 0.01) increased the number of entries and time spent in open arm comparable with standard diazepam at the dose of 10 mg/kg. b.w. p.o. In the open field test, pet. ether extract (50 mg/kg b.w. p.o.) showed significant increase (P < 0.01) in ambulation and activity in the center. Chloroform extract (50 mg/kg b.w p.o.) was significant (P < 0.05) for both ambulation and center activity. Pet. ether extract (50 mg/kg b.w. p.o) also showed significant activity (P < 0.01) in rota rod test. All the results are comparable with standard diazepam at the dose of 1 mg /kg b.w, p.o. Moreover all the extracts showed significant (P < 0.01) increase in the phenobarbitone induced sleeping time among which pet.ether showed more prominent activity (36%) comparable with control. The results revealed that, the active pet.ether extract and chloroform extract of leaf galls of Piper nigrum Linn is worthwhile to develop the bioactive principle for anxiolytic activity.

Differential GPS에 기초한 도로 뱅크각의 실시간 추정기법

한진오(Jin-Oh Hahn),Rajesh Rajamani(Rajesh Rajamani),유승한(Seung-Han You),이교일(Kyo II Lee) 한국자동차공학회 2002 한국자동차공학회 춘 추계 학술대회 논문집 Vol.2002 No.5_3

This paper presents a novel approach to estimate the road bank angle using a disturbance observer. The disturbance observer estimates the lumped disturbances, which include the effects of the system parametric uncertainty and the road bank angle. Based on the estimated disturbances, the amonut of disturbance caused by the system parametric variations is identified using an adaptive gradient law with a projection algorithm. With the system variations identified, the value of road bank angle is extracted ITom the estimated disturbance provided by the disturbance observer. The performance and accuracy of the proposed road bank angle estimation algorithm is verified by numerical and experimental results.

Structural Vibration Control for Broadband Noise Attenuation in Enclosures

Kailash Krishnaswamy,Rajesh Rajamani,Jong Jin Woo,Young Man Cho 대한기계학회 2005 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.19 No.7

This paper develops and evaluates several strategies for structural vibration control with the objective of attenuating broadband noise inside a rectangular enclosure. The strategies evaluated include model-independent collocated control, model-based feedback control and a new "modal-estimate" feedback strategy. Collocated control requires no knowledge of model parameters and enjoys the advantage of robustness. However, effective broadband noise attenuation with co located control requires a large number of sensor-actuator pairs. Model-based controllers, on the other hand, can be theoretically effective even with the use of a single actuator. However, they suffer from a lack of robustness and are unsuitable from a practical point of view for broadband structural vibration applications where the dynamic models are of large order and poorly known. A new control strategy is developed based on attenuating a few structural vibration modes that have the best coupling with the enclosure acoustics. Broadband attenuation of these important modes can be achieved using a single actuator, a limited number of accelerometers and limited knowledge of a few modal functions. Simulation results are presented to demonstrate the effectiveness of the developed strategy.

Structural Vibration Control for Broadband Noise Attenuation in Enclosures

Krishnaswamy Kailash,Rajamani Rajesh,Woo Jong Jin,Cho Young Man The Korean Society of Mechanical Engineers 2005 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.19 No.7

This paper develops and evaluates several strategies for structural vibration control with the objective of attenuating broadband noise inside a rectangular enclosure. The strategies evaluated include model-independent collocated control, model-based feedback control and a new 'modal-estimate' feedback strategy. Collocated control requires no knowledge of model parameters and enjoys the advantage of robustness. However, effective broadband noise attenuation with colocated control requires a large number of sensor-actuator pairs. Model-based con-trollers, on the other hand, can be theoretically effective even with the use of a single actuator. However, they suffer from a lack of robustness and are unsuitable from a practical point of view for broadband structural vibration applications where the dynamic models are of large order and poorly known. A new control strategy is developed based on attenuating a few structural vibration modes that have the best coupling with the enclosure acoustics. Broadband attenuation of these important modes can be achieved using a single actuator, a limited number of accelerometers and limited knowledge of a few modal functions. Simulation results are presented to demonstrate the effectiveness of the developed strategy.

Robust H∞ Observer-based Stabilization of Linear Discrete-time Systems with Parameter Uncertainties

Cherifa Bennani,Fazia Bedouhene,Hamza Bibi,Ali Zemouche,Rajesh Rajamani,Khadidja Chaib-Draa,Abdel Aitouche 제어·로봇·시스템학회 2019 International Journal of Control, Automation, and Vol.17 No.9

This paper addresses the problem of observer-based stabilization of discrete-time linear systems in presence of parameter uncertainties and ℓ2-bounded disturbances. We propose a new variant of the classical two-stepLMI approach. In the first step, we use a slack variable technique to solve the optimization problem resulting from stabilization by a static state feedback. In the second step, a part of the slack variable obtained is incorporated in the H∞ observer-based stabilization problem, to calculate simultaneously the Lyapunov matrix and the observer-based controller gains. The effectiveness of the proposed design methodology is demonstrated using the dynamic model of a quadruple-tank flow process system. Additional numerical illustrations are presented to show the superiority of the proposed Modified Two-Step Method (MTSM) from a LMI feasibility point of view.

A Novel Real-Time Capacitance Estimation Methodology for Battery-Less Wireless Sensor Systems

Hwa Soo Kim,Sivaramakrishnan, Shyam,Sezen, A Serdar,Rajamani, Rajesh IEEE 2010 IEEE SENSORS JOURNAL Vol.10 No.10

<P>This paper presents a novel method to read a passive capacitive sensor in telemetry by using inductive coupling. While classical inductive coupling approaches measure sensor capacitance by identifying the resonant frequency of the sensor with a sweep of radio frequency (RF) signals, the proposed method estimates the capacitance change in real-time by algebraically manipulating two measurements (the magnitude and the phase of the reflected sensor impedance). Only one RF signal is used in the proposed method instead of a frequency sweep. Analysis is provided to show that some physical parameter errors can deteriorate the capability of the proposed method in accurately measuring sensor capacitance. However, the use of a first order calibration procedure based on error analysis overcomes this shortcoming. Extensive experimental results with the proposed method combined with a first order calibration show that multifrequency and rapid changes in sensor capacitance can be estimated reliably under varying locations and orientations of the interrogator. The battery-less wireless sensors enabled by the developed technology in this paper can be widely used for measurement of fluid pressure, force, acceleration and other capacitance-change based sensor measurements.</P>