2005 Publications http://localhost:8080/xmlui/handle/123456789/1320 2026-04-09T08:25:56Z 2026-04-09T08:25:56Z Srinivasan, A Pillai, U T S Pai, B C http://localhost:8080/xmlui/handle/123456789/3672 2021-02-08T14:00:34Z 2005-01-01T00:00:00Z

Microstructure and mechanical properties of Si and Sb added AZ91 magnesium alloy Srinivasan, A; Pillai, U T S; Pai, B C The effect of Si (individual and combined) with 0.2 pet Sb additions on the microstructure and mechanical properties of permanent mold AZ91 alloy has been studied. The results indicate that Si addition introduces a Chinese script Mg2Si phase at the grain boundary along with the Mg17Al12-beta phase and reduces ductility and. strength of the alloy both at room and high temperatures. A small amount of Sb addition modifies the Mg2Si phase besides distributing it evenly along the grain boundary. Improved room- and high-temperature mechanical properties are observed in Sb added AZ91 + xSi alloys. However, maximum properties are noticed with the alloy having the combined addition of 0.2 silicon and antimony. Fractograpy of tensile- and impact-tested AZ91 alloy shows cleavage and brittle type of failure. Addition of Si reduces the quasi-cleavage planes, whereas Sb addition increases it while also increasing the plastic zone.

2005-01-01T00:00:00Z Sandhya, C Binod, P Nampoothiri, K M Szakacs, G Pandey, A http://localhost:8080/xmlui/handle/123456789/3671 2021-02-08T13:48:52Z 2005-01-01T00:00:00Z

Microbial synthesis of chitinase in solid cultures and its potential as a biocontrol agent against phytopathogenic fungus Colletotrichum gloeosporioides Sandhya, C; Binod, P; Nampoothiri, K M; Szakacs, G; Pandey, A Antifungal activity of chitinase can be effectively utilized in biologic pest control strategies. Because solid-state cultivation has been termed a cost-effective means for fungal growth and metabolite production, chitinase production by Trichoderma harzianum was studied using wheat bran-based solid medium containing 1% colloidal chitin. Chitinase synthesis was found to be growth associated because maximum enzyme (5.4 U/g of dry substrate) and biomass production occurred at 72 h. Substrate moisture had a critical impact on chitinase production; five grams of medium having an initial moisture content of 68.4% when incubated for 72 h increased the enzyme yield to 9.3 U/g of dry substrate. Optimization of colloidal chitin concentration showed that improvements in chitinase yield and maximum activity were attained with a 2% (w/w) concentration. Supplementation of additional nitrogen sources also influenced enzyme production, and the best yield was obtained with yeast extract. The effect of crude chitinase on hyphal morphology of the phytopathogenic fungus Colletotrichum gloeosporioides was swelling as well as lysis of hyphal wall, depending on the age of the mycelium. Studies of pH and thermal stability showed that crude culture filtrate was active over pH 4.0-6.0 and retained about 48.2% activity after 40 min of incubation at 40 degrees C.

2005-01-01T00:00:00Z Vijay Nair, G Sreekumar, V Bindu, S Suresh, E http://localhost:8080/xmlui/handle/123456789/3670 2021-02-08T13:45:51Z 2005-01-01T00:00:00Z

Two unprecedented multicomponent reactions involving N-heterocyclic carbenes, activated acetylenes, and aldehydes Vijay Nair, G; Sreekumar, V; Bindu, S; Suresh, E Two unprecedented multicomponent reactions of N-heterocyclic carbenes involving activated acetylenes and aldehydes are described.

2005-01-01T00:00:00Z Vijay Nair, G Sindhu Mathai Smitha C Mathew Rath, N P http://localhost:8080/xmlui/handle/123456789/3669 2021-02-08T13:45:12Z 2005-01-01T00:00:00Z

A stereoselective synthesis of spiro-dioxolanes via the multicomponent reaction of dicarbomethoxycarbene, aldehydes and 1,2-or 1,4-diones Vijay Nair, G; Sindhu Mathai; Smitha C Mathew; Rath, N P The three component reaction of acyclic carbonyl ylides generated from dicarbomethoxycarbene and aldehydes with 1,2- and 14-diones is described. The reaction afforded the corresponding spiro-dioxolanes in good yields.

2005-01-01T00:00:00Z