Active elastic dimers: self-propulsion and current reversal on a featureless track

We present a Brownian inchworm model of a self-propelled elastic dimer in the absence of an external potential. Nonequilibrium noise together with a stretch-dependent damping form the propulsion mechanism. Our model connects three key nonequilibrium features -- position-velocity correlations, a nonzero mean internal force, and a drift velocity. Our analytical results, including striking current reversals, compare very well with numerical simulations. The model unifies the propulsion mechanisms of DNA helicases, polar rods on a vibrated surface, crawling keratocytes and Myosin VI. We suggest experimental realizations and tests of the model.Comment: 4 page

Small Farm Goat Production in Semi-Arid Region of Uttar Pradesh

Majority of selected goat farmers were landless and marginal (69%) with an annual average income of Rs.I9200.00. However, average income of small and medium goat farmers were about Rs.25500.00.Ownership pattern of goats revealed that about 78% goats were owned by the landless and marginal farmers. Majority of the farmers had Barbari/Barbari type goats (54%) followed by non-descript (43%) and Sirohi type goats (3%). Furthermore, 69 per cent goat houses were of Kaccha type and 49 per cent of selected respondent availed private veterinary services for their goats however, 40 percent of the goat farmers used home remedies. Merely, 11 per cent of the respondents visited government veterinary hospitals Though, poor socio-economic status cannot be ignore for the goat improvement in study village, some policy support is imperative to encourage goat farmers for their overall development

Wear Studies of Gel Cast Silicon Nitride Ceramics and Effect of Wear Parameters by Anova

Amongst a broad group of engineering ceramic materials which combine low density with very good mechanical properties in a wide temperature ranges, nitrides are of particular importance. Tribological component materials demanding high reliability in the use are presently available and might be applied in various severe wear, thermal and mechanical applications. In the Present work aims to preparation of silicon nitride wear samples by gel casting method and it continues to determination of affect of input parameters sliding distance, sliding speed and load applied on the output wear rate of silicon nitride ceramics. An attempt has been made to study the effect of wear parameters like applied load, sliding speed and sliding distance on the dry sliding wear of Silicon nitride ceramics. Wear tests of the Silicon nitride ceramics are carried out on pin-on-disc wear testing machine by varying the sliding speed (1m/s, 2m/s and 3m/s), sliding distance (600m, 1000m, 1200m, 1500m and 1800m) and applied load( 20N, 30N and 40N). The effect of these parameters on wear rate has been determined by using ANOVA analysis