Long-range correlations in a locally driven exclusion process

We show that the presence of a driven bond in an otherwise diffusive lattice gas with simple exclusion interaction results in long-range density-density correlation in its stationary state. In dimensions $d>1$ we show that in the thermodynamic limit this correlation decays as $C(r,s)\sim (r^2+s^2)^{-d}$ at large distances $r$ and $s$ away from the drive with $|r-s|>>1$. This is derived using an electrostatic analogy whereby $C(r,s)$ is expressed as the potential due to a configuration of electrostatic charges distributed in $2d$-dimension. At bulk density $\rho=1/2$ we show that the potential is that of a localized quadrupolar charge. At other densities the same is correct in leading order in the strength of the drive and is argued numerically to be valid at higher orders.Comment: 5 pages, 4 figure

Non-local response in a lattice gas under a shear drive

In equilibrium, the effect of a spatially localised perturbation is typically confined around the perturbed region. Quite contrary to this, in a non-equilibrium stationary state often the entire system is affected. This appears to be a generic feature of non-equilibrium. We study such non-local response in the stationary state of a lattice gas with a shear drive at the boundary which keeps the system out of equilibrium. We show that a perturbation in the form of a localised blockage at the boundary, induces algebraically decaying density and current profile. In two examples, non-interacting particles and particles with simple exclusion, we analytically derive the power-law tail of the profiles.Comment: 32 pages, 7 figure

ASSESSMENT OF DRINKING WATER QUALITY IN TRIBAL DOMINATED VILLAGES OF BARKAGAON, HAZARIBAG, JHARKHAND, INDIA

Water is most essential component for the survival of any kind of life on the planet Earth. Quality and quantity of water at any place play a vital role in health, wealth and prosperity of life. Geogenic contaminants including fluoride have affected ground water in more than 200 districts of 19 states of India. Fluoride is one of the most essential elements for calcification of bones and teeth where as excess intake (above 1.5 mg/lit.) may cause skeletal, non skeletal and dental fluorosis. Drinking water samples from five tribal dominated villages of Barkagaon (230 52′ 5′′ N latitude and 850 14′ 15′′ E longitude), Hazaribag, Jharkhand, India were taken fortnightly from hand pump during rainy, winter and summer seasons (July 2011- June 2012) for fluoride analysis as per standard protocol of APHA (2005) and the results showed that all the samples contained higher concentration. The highest average concentration of fluoride was recorded in Bhurkundwa village (3.84±0.8 mg/lit.) where as it was lowest in Aswa village (1.89± 0.8 mg/lit). We have studied the impact of fluoride among 426 school children (06-16 yrs) with reference to Dean’s Index for dental fluorosis which reveals that almost 87% were suffering from dental fluorosis. The results clearly indicate that the dental fluorosis among children is directly related to fluoride concentration in drinking water. Our opinion regarding the higher fluoride concentration in the study area is due to excess mineral exploration. Thus necessary steps must be taken to supply the quality drinking water to the locality for the maintenance of the health of tribal people

Diseases and their management in cage culture

The current trend in aquaculture development is towards increased intensification and commercialization of aquatic production. Like other farming sectors, the likelihood of major disease problems occurring increases as aquaculture activities intensify. Disease is now a primary constraint to the culture of many aquatic species, impeding both economic and sociadevelopment in many countries. Addressing health questions with both pro-active and reactive programmes has become a primary requirement for sustaining aquaculture production and product trade. It is reported that the principal diseases in cage aquaculture of marine finfish and shellfish in Asia are caused by environmental and management affects, nutritional causes, and viral, bacterial, parasitic, and fungal pathogen

Overview of cage culture – Indian perspective

The decline of fish stocks has been a motivating factor for expanding the role of aquaculture in the fishing industry. Nowadays, the trend demonstrates that while wild harvest volume remains stable (or is in decline in several fisheries), aquaculture production has increased. In this situation, cage farming has an important role in meeting the global demand for fish products. It is one the alternative source to increase the aquaculture production. The development of this type of fish production is a long-term solution to meet the global demand for fisheries products and also provides economic opportunities for displaced and landless fishermen

Engineering aspects of cage design, mooring and net design for open sea cage farming in India

Cage is an aquaculture production structure comprising of a rigid floating frame, flexible net materials and mooring system (synthetic mooring rope, buoy and anchor) with a round or square shape floating net pen to hold and culture large number of fishes and other aquatic resources which can be installed in reservoir, river, lake or sea. The design and operating variables in engineering aspects of an open sea cage is of great concern in mariculture operations as they are installed in exposed sites in the off shore areas. The design of the cage and its accessories is specially made in agreement to the individual farmer’s requirements. A well engineered cage design will provide the opportunity to reduce the cost of the cages. HDPE material is found to be suitable to make cage frame for open sea cages. The HDPE float frames installed in open unprotected water can withstand wave conditions. Round cage (volume depends on diameter) with floatation system made of butt-welded HDPE pipes, designed for the culture of fishes such as milkfish, mullet, cobia or pompano, sea bass and lobsters, and this very well used in many countries

Some aspects of nursery rearing of the Asian seabass (Lates calcarifer, Bloch) in indoor cement tanks

Asian seabass (Lates calcarifer) is a highly valued food fish of great culture potential. Nursery rearing of Asian seabass in indoor cement tanks was undertaken. Fish were fed on artificial diets at 4% body weight and four times feeding per day with periodical size grading. Mean weight and length at the end of the 45 days experimental period was 8.55 g and 91.03 mm, respectively. While survival rate was 100%, FCR and PER at the end of the 45 days experimental period was 1.15 and 1.07%, respectively. The results of various growth parameters studied showed that the values obtained were in conformity with earlier reports on nursery rearing of Asian seabass under varied rearing systems and growth conditions

Perspectives on mariculture in India

The aquaculture sector in India has a long history and has witnessed an increase in production for the last two decades with an annual growth rate of 6-7%. This means that India is the second largest producer of farmed fish in the world after China. At present, freshwater aquaculture contributes to a major proportion of the aquaculture production from India (FAO, 2014). In India, brackish water aquaculture is a traditional practise in natural coastal low land areas such as pokkali fields (salt resistant deepwater paddy fields along the Kerala coast), bheries (man made impoundments in coastal wetlands of West Bengal state), khar lands (tidal lands in Karnataka state) and khazan lands (saline flood plains along tidal estuaries in Goa) with varying production capacities and depending on tidal influences and natural supply of seeds (Kutty, 1999). After several trials, under different R&D programs, scientific coastal farming was initiated in the early 1990s with the active involvement of different stakeholders. Since then, shrimp farming has grown tremendously and at present, dominates coastal aquaculture. However, the frequent problems in shrimp culture raises the question on the sustainability of coastal aquaculture as it is solely dependent on a single group i.e. shrimp. Therefore, species diversification with high value marine finfish is now being considered to develop a sustainable and ecofriendly coastal aquaculture industry in India

Alternative marine finfish species for Coastal and Open sea aquaculture in India-Current status and challenges

Aquaculture is one of the most rapidly growing food producing sectors in the world with a potential to meet the ever-growing demand for food and nutrition. Aquaculture production had reached 66.6 million tonnes in 2012 (FAO, 2014) and continues to grow every year. The world food fish aquaculture production has expanded at an average annual rate of 6.2% during 2000 - 2012. The Indian aquaculture scenario too mirrors the global picture, with an annual growth rate of 6-7% in the last two decades. This has made lndia the second largest producer of farmed fish in the world after China. lndia has transformed an extensive system of aquaculture into an intensive and commercial enterprise in the last three decades. Currently, both freshwater and coastal areas are utilised for aquaculture purposes, with freshwater aquaculture contributing a major portion in the total production in lndia (FAO, 2014)