Identification of RAPD markers linked to sex determination in guggal [Commiphora wightii (Arnott.)] Bhandari

Samantaray, Sanghamitra,Geetha, K.A.,Hidayath, K.P.,Maiti, Satyabrata The Korean Society of Plant Biotechnology 2010 Plant biotechnology reports Vol.4 No.1

Decamer RAPD primers were tested on dioeceious and hermaphrodite plants of Commiphora wightii to identify sex-specific molecular markers. Sixty different random decamer primers were screened out of which only three primers were found to be associated with sex expression. A ~1,280-bp fragment from the primer OPN06 was found to be present in all the female individuals. Another primer OPN 16 produced a unique ~400-bp amplification product in only hermaphrodite individuals. The third marker, OPA20 amplified a ~1,140-bp fragment from female and hermaphrodite DNAs, but failed to do so from the male plant DNAs.

EVA/Clay Nanocomposite by Solution Blending: Effect of Aluminosilicate Layers on Mechanical and Thermal Properties

Pramanik, M.,Srivastava, S.K.,Samantaray, B.K.,Bhowmick, A.K. The Polymer Society of Korea 2003 Macromolecular Research Vol.11 No.4

Ethylene vinyl acetate (EVA)/clay nanocomposites were synthesized by blending a solution of ethylene vinyl acetate copolymer containing 12% vinyl acetate abbreviated as EVA-12 in toluene and dispersion of dodecyl ammonium ion intercalated montmorillonite (l2Me-MMT) in N,N-dimethyl acetamide (DMAc). X-ray patterns of sodium montmorillonite ($Na^+$-MMT) and 12Me-MMT exhibited $d_{001}$ peak at $2{\theta}=7.4^{\circ}$ and $2{\theta}=5.6^{\circ}$ respectively; that is, the interlayer spacing of MMT increased by about 0.39 nm due to intercalation of dodecyl ammonium ions. The XRD trace of EVA showed no peak in the angular range of $3-10^{\circ}(2{\theta})$. In the XRD patterns of EVA/clay hybrids with clay content up to 6 wt% the basal reflection peak of 12Me-MMT was absent. leading to the formation of delaminated configuration of the composites. When the 12Me-MMT content was 8 wt% in the EVA-12 matrix, the hybrid revealed a peak at about $2{\theta}=5.6^{\circ}$, owing to the aggregation of aluminosilicate layers. Transmission electron microscopic photograph exhibited that an average size of 12-15 nm clay layers were randomly and homogeneously dispersed in the polymer matrix, which led to the formation of nanocomposite with delaminated configuration. The formation of delaminated nanocomposites was manifested through the enhancement of mechanical properties and thermal stability, e.g. tensile strength of an hybrid containing only 2 wt% 12Me-MMT was enhanced by about 36% as compared with neat EVA-12.

Control of compliant legged quadruped robots in the workspace

Gor, M M,Pathak, P M,Samantaray, A K,Yang, J-M,Kwak, S W SAGE Publications 2015 Simulation Vol.91 No.2

<P>Locomotion control of a quadruped robot requires a well-defined gait pattern (i.e., a coordinated actuation of its four legs in some particular fashion with respect to time). It is of practical importance to move the leg tips in a desired trajectory in order to achieve specific objectives such as to avoid obstacles, minimize energy consumption and locomotion time. Along with body displacement, body orientation is an equally important limit parameter during each leg step of the gait pattern. There are several possible gait patterns that maintain stable and aesthetically pleasing locomotion, and most of these are biologically inspired. This article presents quadruped locomotion control in the workspace through a novel control scheme in which the leg forward motion is controlled in the workspace while the body forward motion is controlled by providing the required effort directly to the joint actuators. In this control approach, the leg tip trajectory error drives a proportional-integral controller that is then transformed through the Jacobian to generate the corrective joint torques. For the body forward motion, leg motion is arrested and the joints are provided with opposite motion, which are controlled by a proportional-integral-derivative controller. The proposed method is simple and easy to implement in the workspace. The performance of the proposed control scheme is evaluated through simulations and animations.</P>

Posture Control Strategy of a Platform using a RP Manipulator

M. M. Gor,P. M. Pathak,A. K. Samantaray,J.-M. Yang,S. W. Kwak 제어로봇시스템학회 2014 제어로봇시스템학회 국제학술대회 논문집 Vol.2014 No.10

This paper is an attempt to develop a posture control strategy for quadruped robot. Here, a concept of posture control is proposed, in which, a revolute and prismatic (RP) manipulator with payload at the end is used to control the body orientation. For the said analysis necessary model is developed in the bond graph and efficacy of the proposed strategies is validated through simulation results of the developed model.

EVA/Clay Nanocomposite by Solution Blending: Effect of Aluminosilicate Layers on Mechanical and Thermal Properties

M.Pramanik,S.K.Srivastava,B.K.Samantaray,A.K.Bhowmick 한국고분자학회 2003 Macromolecular Research Vol.11 No.5

Ethylene vinyl acetate (EVA)/clay nanocomposites were synthesized by blending a solution of ethylene vinyl acetate copolymer containing 12% vinyl acetate abbreviated as EVA-12 in toluene and dispersion of dodecyl ammonium ion intercalated montmorillonite (12Me-MMT) in N,N-dimethyl acetamide (DMAc). X-ray patterns of sodium montmorillonite (Na+-MMT) and 12Me-MMT exhibited d001 peak at 2θ=7.4o and 2θ=5.6o respectively; that is, the interlayer spacing of MMT increased by about 0.39 nm due to intercalation of dodecyl ammonium ions. The XRD trace of EVA showed no peak in the angular range of 3-10o (2θ). In the XRD patterns of EVA/clay hybrids with clay content up to 6 wt% the basal reflection peak of 12Me-MMT was absent, leading to the formation of delaminated configuration of the composites. When the 12Me-MMT content was 8 wt% in the EVA-12 matrix, the hybrid revealed a peak at about 2θ=5.6o, owing to the aggregation of aluminosilicate layers. Transmission electron microscopic photograph exhibited that an average size of 12-15 nm clay layers were randomly and homogeneously dispersed in the polymer matrix, which led to the formation of nanocomposite with delaminated configuration. The formation of delaminated nanocomposites was manifested through the enhancement of mechanical properties and thermal stability, e.g. tensile strength of an hybrid containing only 2 wt% 12Me-MMT was enhanced by about 36% as compared with neat EVA-12.

Fault accommodation in compliant quadruped robot through a moving appendage mechanism

Gor, M.M.,Pathak, P.M.,Samantaray, A.K.,Yang, J.-M.,Kwak, S.W. Elsevier 2018 Mechanism and machine theory Vol.121 No.-

<P><B>Abstract</B></P> <P>Quadruped robots provide better stability and speed in comparison to other legged robots. However, its joint actuator or sensor failure severely affects locomotion. Strategies for actuator and sensor fault accommodation in a compliant legged quadruped are presented here. A pair of orthogonally mounted moving appendages mechanism is proposed here to accommodate locked joint failure. These appendages as rack mounted inertias perform controlled motion during actuator failure. A strategy for sensor fault accommodation is also presented. A three-dimensional multi-body dynamics model of quadruped robot and its fault accommodation strategies are developed using bond graph modeling approach. The control performance is validated both through simulations and experiments.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Locked-joint and sensor faults of a quadruped robot are detected and isolated. </LI> <LI> Fault tolerant operation of a quadruped robot is considered for various missions. </LI> <LI> Actuator faults are accommodated with controlled moving appendages. </LI> <LI> Sensor fusion is used to reconstruct faulty sensor data. </LI> <LI> Online system reconfiguration is validated using simulations and experiments. </LI> </UL> </P>

Development of a compliant legged quadruped robot

Gor, M M,Pathak, P M,Samantaray, A K,Alam, K,Kumar, P,Anand, D,Vijay, P,Sarkar, R,Yang, J-M,Kwak, S W Springer-Verlag 2018 Sādhanā Vol.43 No.7

EVA/Clay Nanocomposite by Solution Blending

M. Pramanik,S. K. Srivastava,B. K. Samantaray,A. K. Bhowmick 한국고분자학회 2003 Macromolecular Research Vol.11 No.4