Plasma production and preliminary results from the ADITYA Upgrade tokamak

The Ohmically heated circular limiter tokamak ADITYA (R0 =75 cm,a =25 cm) has been upgraded to a tokamak named the ADITYA Upgrade (ADITYA-U) with an open divertor configuration with divertor plates.The main goal of ADITYA-U is to carry out dedicated experiments relevant for bigger fusion machines including ITER,such as the generation and control of runaway electrons,disruption prediction,and mitigation studies,along with an improvement in confinement with shaped plasma.The ADITYA tokamak was dismantled and the assembly of ADITYA-U was completed in March 2016.Integration of subsystems like data acquisition and remote operation along with plasma production and preliminary plasma characterization of ADITYA-U plasmas are presented in this paper.     

Renewable Resin Precursor and Residual Filler Modified Poly(vinyl chloride) Foam,Investigation of Microcellular Development and Moisture Absorption Behavior

Poly(vinyl chloride) plastisol-based foams were prepared with epoxidized soybean oil and residual low cost fillers. Microstructural characterizations using scanning electron microscopy were carried out to understand the microcellular morphology. Absence of epoxy groups in Fourier transform infrared spectroscopy spectra of epoxidized soybean oil-modified–poly(vinyl chloride) plastisol foams indicated the occurrence of ring opening reaction between poly(vinyl chloride) plastisol and epoxidized soybean oil, signifying epoxidized soybean oil’s role as HCl scavenger. X-ray diffraction study indicated increased crystallinity of filler modified poly(vinyl chloride) plastisol/epoxidized soybean oil foams, suggesting their role as possible nucleating agents. Foams with fillers also showed reduced water uptake, which were in good agreement with other characterizations.     

Incorporation of epoxidized soybean oil as co‐matrix in epoxy resin toward developing plastisol/particulate toughened glass fiber composites

Epoxidized soybean oil was incorporated as a co‐matrix into an epoxy resin, and the hybrid resin system was used for preparing glass fiber‐reinforced composites. Effect of addition of poly(vinyl chloride) plastisol and selected particulate fillers (fly ash and wood flour) to epoxy/epoxidized soybean oil matrix on mechanical and water uptake properties of glass fiber‐reinforced composites were studied. Fourier transform infrared spectroscopy was used to reveal the curing state of these composites. It was observed that tensile strengths and moduli decreased with the inclusion of all additives. However, addition of poly(vinyl chloride) plastisol, fly ash, and wood flour particulate fillers showed significant increase in impact strengths compared with neat epoxy composite in a synergistic manner. Water uptake results of the composites were found to be in good agreement with ? OH peak intensities obtained from Fourier transform infrared spectroscopy. Finally, acousto‐ultrasonic nondestructive technique was successfully used to assess damage states and to relate stress wave factors with tensile strength properties of modified epoxy‐based glass fiber composites. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40586.     

Integration of biobased functionalized feedstock and plastisol in epoxy resin matrix toward developing structural jute biocomposites with enhanced impact strength and moisture resistance properties

Epoxy resin matrix based on diglycidyl ether of bisphenol A (DGEBA) was modified with addition of epoxidized soybean oil (ESBO). Structural jute composites prepared with ESBO modified DGEBA resin showed a decrease in tensile strengths, owing to reduced cross linking density. Percentage elongation of the samples increased with addition of ESBO. An optimized composition was identified, at which the composite showed increase in tensile strength, modulus and elongation. Interestingly, impact strengths increased initially with incorporation of ESBO, but with further increase in ESBO, impact strengths decreased. Structural Jute composites were also prepared by incorporating polyvinyl (chloride) (PVC) plastisol into the modified matrix which showed an increase in both tensile and impact strengths. Fourier transform infrared spectroscopy (FT‐IR) analysis indicated the curing state of the composites. The spectrum peaks became increasingly stronger in the O H band with increasing ESBO quantities. This could be attributed to the hydrophilic nature of ESBO, a result that was well supported by the moisture absorption test. Although, water uptake capacity of ESBO/DGEBA modified matrix composites recorded increasing trend with increased ESBO content, with inclusion of plastisol, the water uptake values dropped. Composite with DGEBA/ESBO/plastisol modified matrix actually recorded water uptake capacity comparable to composite with neat DGEBA, possibly owing to improved interfacial adhesion and hydrophobic nature of PVC plastisol. POLYM. COMPOS., 37:391–397, 2016. © 2014 Society of Plastics Engineers     

Latent‐space Dynamics for Reduced Deformable Simulation

We propose the first reduced model simulation framework for deformable solid dynamics using autoencoder neural networks. We provide a data‐driven approach to generating nonlinear reduced spaces for deformation dynamics. In contrast to previous methods using machine learning which accelerate simulation by approximating the time‐stepping function, we solve the true equations of motion in the latent‐space using a variational formulation of implicit integration. Our approach produces drastically smaller reduced spaces than conventional linear model reduction, improving performance and robustness. Furthermore, our method works well with existing force‐approximation cubature methods.