Informatics Publishing Limited

Deb Prasad Ray ¹, Pratik Satya ², Sabyasachi Mitra ², Pradipta Banerjee ¹, Rakesh Kumar Ghosh ¹

Affiliations
1 National Institute of Research on Jute and Allied Fibre Technology 12, Regent Park, Kolkata – 700040, IN
2 Central Research Institute for Jute and Allied Fibres, Barrakpore, Kolkata–700 120, IN

Abstract

Ramie is considered as a valuable textile fibre and is known from ancient times. It is considered as the queen of all fibres due to its
lustre as well as high tenacity, enhanced strength and good microbial resistivity. The fibre is extracted from the stem of the plant.
It is an herbaceous perennial growing plant and is one of the oldest vegetable fibres that have been used for thousands of years.
The raw ramie fibres obtained by decortications consists of long fibres in which they are tightly cemented together by gum. The
raw ramie fibre contains high proportion (25-30%) of colloidal pectic gummy substances. It is apparent that removal of gum from
decorticated ramie is necessary to unveil its unique properties and make it suitable for textile purpose. The cost of extraction and
degumming is the major disadvantage of ramie fibre. The process of removal of gum requires chemical, microbial or rather
enzymatic treatment which is difficult to perform in farmers’ level. Literature scan showed that there is hardly any standard method
of degumming. Moreover, no standard method has been found full proof for extraction of textile grade ramie fibre. Therefore, an
integrated methodology which include all the above mentioned conventional methods and non-conventional biotechnological
technologies have been evaluanted to degum raw ramie fibres to obtain the textile grade ramie fibre.

Keywords

Ramie, Degumming, Natural Fibre, Chemical Degumming, Microbial Degumming, Textile

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Sabyasachi Mitra ¹, Vishnu Sharma ¹, Senthil Kalyandrum ¹, Romesh Chandra ¹, Sandeep Singh ¹, Rakhee Menon ¹, Ankur Patel ¹, Amitava Roy ¹, Archana Sharma ¹, Krishna Kanakgiri ², Mayank Mishra ²

Affiliations
1 Accelerator and Power Pulse Division, Bhabha Atomic Research Centre, Mumbai, IN
2 Veermata Jijabai Technological Institute, Mumbai, IN

Abstract

In this paper effect of stray capacitance on output voltage of the Marx Generator is studied. Stray capacitances formed between high voltage metallic structures of Marx generator and its ground enclosure play a critical role in determining the voltage and rise time of the output pulse. With increase in enclosure diameter erected leakage inductance increases and stray capacitance reduces, with decrease and vice versa. Eventually in both the cases output voltage reduces and rise time increases. This effect is predominant in fast rising low energy MARX generators having low erected capacitances. In this paper effort has been made to quantify these effects. Simulations were carried out for different enclosure structures to find out their effect on output voltage and rise time with a fixed load. It was observed that conical enclosure helps in mitigating this problem in MARX generator. Simulations were also carried out to optimize the flaring angle of the conical enclosure to obtain maximum output voltage. Simulated results are experimentally validated using a 22 stage 450 kV MARX generator. Details of the analysis, simulations and experimental results are narrated thoroughly in this paper.

Keywords

Marx Generator, stray capacitance, rise time, stray inductance

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