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The aim of the present study was to analyse the influence of year, season and parity on productive and reproductive performances in 110 Soviet Chinchilla and 64 White Giant rabbits under tropical climatic conditions of Tamil Nadu in the period between 2005 and 2009. A total of 731 records for the overall leastsquares means for litter size at birth and weaning, litter weight at birth and weaning, average weight of kit at birth and weaning and pre-weaning growth rate in Soviet Chinchilla rabbits were 5.1±0.1, 3.7±0.1, 256.4±6.9 g, 2465.4±73.6 g, 50.4±0.7 g, 694.1±13.1 g and 15.3±0.3 g/d, respectively, and the values for White Giant rabbits were 5.1±0.1, 4.1±0.1, 259.6±6.1 g, 2432.6±68.7 g, 50.8±0.4 g, 614.6±13.5 g and 13.4±0.3 g/d, respectively. Breed had significant effect on litter size at weaning (P<0.01), average weight of kit at weaning (P<0.05) and pre-weaning growth rate (P<0.01). Year of birth had significant effect on litter size and litter weight at birth (P<0.05), litter size and litter weight at weaning (P<0.01), average weight of kits at weaning and pre-weaning growth rate (P<0.01) in Soviet Chinchilla and White Giant rabbits. Season of birth had significant effect on litter weight at birth and weaning (P<0.05), average weight of kits at birth (P<0.05) and weaning (P<0.01) and pre-weaning growth rate (P<0.01) in both the breeds. Parity had significant effect on litter weight and average weight of kits at weaning (P<0.01) and pre-weaning growth rate (P<0.01). The study revealed that the Soviet Chinchilla and White Giant breeds performed well in the tropical climatic conditions of Tamil Nadu and could be used for profitable meat production. The significant influence of factors such as year of birth and season of birth observed on different production traits emphasises the role played by the management in optimising the realisation of genetic potential under local agro-climatic conditions.

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The surface behaviour of surface mechanical attrition treated (SMATed) and plasma-nitrided AISI 2205 and AISI 304L steels was investigated in the present study. The intersection of the mechanical twins formed the submicron-size rhombic blocks in the surface region of the SMATed AISI 304L steel. However, such microstructural feature was absent in the SMATed AISI 2205 steel. The improvement in the surface-hardness due to the SMAT was about 70-80% for AISI 2205, and more than 100% for AISI 304L steel. The nature of passive film formed on the AISI 2205 steel was different from the AISI 304L steel. Passive film formed on the SMATed AISI 304L steel was relatively more unstable than that of the AISI 2205 steel at an elevated electric-potential and in a plasma environment. The plasma-nitriding response was affected due to the different passivation behaviour of the SMATed, and non-SMATed steels.

Wear behaviour of the AISI 4140 steel specimens with various surface conditions was tested against the DLC-coated boronized disc of AISI 4140 steel. Specific wear rate and coefficient of friction (COF) of the as-boronized (AB) pins at 100 and 150 N loads were substantially lower than the boronized-polished (B-P) pins. COF of AB pins was in the range of 0.07-0.09. However, the COF of B-P pins was about 0.13. In case of the DLC-coated pins, underlying boronized surface outperformed the hardened-tempered surface. Wear properties of the DLC-coated pins were improved with an increase in the load. DLC coating on both contacting surfaces gave the lowest specific wear rate of 0.21 × 10 −8 mm 3 N −1 m −1 , which was about 30 times lower than the B-P pins, and COF was in the range of 0.08-0.09.