1,274 research outputs found
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
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 we show that in the
thermodynamic limit this correlation decays as at
large distances and away from the drive with . This is
derived using an electrostatic analogy whereby is expressed as the
potential due to a configuration of electrostatic charges distributed in
-dimension. At bulk density 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
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)
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