2,477 research outputs found
Star formation activity in the southern Galactic HII region G351.63-1.25
The southern Galactic high mass star-forming region, G351.6-1.3, is a HII
region-molecular cloud complex with a luminosity of 2.0 x 10^5 L_sun, located
at a distance of 2.4 kpc. In this paper, we focus on the investigation of the
associated HII region, embedded cluster and the interstellar medium in the
vicinity of G351.6-1.3. We address the identification of exciting source(s) as
well as the census of stellar populations. The ionised gas distribution has
been mapped using the Giant Metrewave Radio Telescope (GMRT), India at three
continuum frequencies: 1280, 610 and 325 MHz. The HII region shows an elongated
morphology and the 1280 MHz map comprises six resolved high density regions
encompassed by diffuse emission spanning 1.4 pc x 1.0 pc. The zero age
main-sequence (ZAMS) spectral type of the brightest radio core is O7.5. We have
carried out near-infrared observations in the JHKs bands using the SIRIUS
instrument on the 1.4 m Infrared Survey Facility (IRSF) telescope. The
near-infrared images reveal the presence of a cluster embedded in nebulous
fan-shaped emission. The log-normal slope of the K-band luminosity function of
the embedded cluster is found to be 0.27 +- 0.03 and the fraction of the
near-infrared excess stars is estimated to be 43%. These indicate that the age
of the cluster is consistent with 1 Myr. The champagne flow model from a flat,
thin molecular cloud is used to explain the morphology of radio emission with
respect to the millimetre cloud and infrared brightness.Comment: 18 pages, 8 figures, To be published in MNRA
Radio and infrared study of the star forming region IRAS 20286+4105
A multi-wavelength investigation of the star forming complex IRAS 20286+4105,
located in the Cygnus-X region, is presented here. Near-infrared K-band data is
used to revisit the cluster / stellar group identified in previous studies. The
radio continuum observations, at 610 and 1280 MHz show the presence of a HII
region possibly powered by a star of spectral type B0 - B0.5. The cometary
morphology of the ionized region is explained by invoking the bow-shock model
where the likely association with a nearby supernova remnant is also explored.
A compact radio knot with non-thermal spectral index is detected towards the
centre of the cloud. Mid-infrared data from the Spitzer Legacy Survey of the
Cygnus-X region show the presence of six Class I YSOs inside the cloud. Thermal
dust emission in this complex is modelled using Herschel far-infrared data to
generate dust temperature and column density maps. Herschel images also show
the presence of two clumps in this region, the masses of which are estimated to
be {\sim} 175 M{\sun} and 30 M{\sun}. The mass-radius relation and the surface
density of the clumps do not qualify them as massive star forming sites. An
overall picture of a runaway star ionizing the cloud and a triggered population
of intermediate-mass, Class I sources located toward the cloud centre emerges
from this multiwavelength study. Variation in the dust emissivity spectral
index is shown to exist in this region and is seen to have an inverse relation
with the dust temperature.Comment: 20 pages, 16 figures, accepted for publication in MNRA
Environmental and social issues in coastal aquaculture
Aquaculture has grown rapidly in the recent years and has promise for
further potential growth. This rapid expansion was possibly because of the
growing demand for aquatic products and the failure of the global capture
fishery, which has been exploited, to or beyond its potential. When the global
catch statistics remains standstill between 80-100 million metric tons per year,
the global aquaculture production is registering an overwhelming annual growth
of 8-14% producing between 20-25 million tons per year. Of the aquaculture
practices, coastal shrimp farming has registered the maximum growth of about
400% in the last decade. The two factors resulting to its boom were the
increasing demand for Indian shrimp and the improved farming technique
CIFE-Status Paper on women in fisheries
Women depend on fishery resources for food, work, income
and identity, especially, to nurture their children. Yet, they
tend to have less control than men over these resources and
the associated wealth. Initiatives in fisheries management
and fisheries conservation are rarely scrutinized for their
potential impacts on women. The World Wide Fund
presented discussion on the proposal for a Marine
Stewardship Council (MSC) development, which is believed
to share this weakness. The MSC ignores the complex
realities of women's work, its diversity and the differing
places they occupy in fish product markets. An examination
is made for the implications of the proposed MSC by
considering its potential impacts on access to fish and its
consumption among different groups of women. (Neis, -B.l.
1996) Women participate in fisheries in different ways in
different sectors
Commodity diversification and geographic concentration of Indian seafood exports
Indian fisheries sector plays an important
role in the socio-economic
development of the country, in view of
its potential contribution to national income,
nutritional security, employment
opportunities, social objectives and export
earnings
Effect of Hedging-Integrated Rule Curves on the Performance of the Pong Reservoir (India) During Scenario-Neutral Climate Change Perturbations
This study has evaluated the effects of improved, hedging-integrated reservoir rule
curves on the current and climate-change-perturbed future performances of the Pong reservoir,
India. The Pong reservoir was formed by impounding the snow- and glacial-dominated Beas
River in Himachal Pradesh. Simulated historic and climate-change runoff series by the
HYSIM rainfall-runoff model formed the basis of the analysis. The climate perturbations used
delta changes in temperature (from 0┬░ to +2 ┬░C) and rainfall (from тИТ10 to +10 % of annual
rainfall). Reservoir simulations were then carried out, forced with the simulated runoff
scenarios, guided by rule curves derived by a coupled sequent peak algorithm and genetic
algorithms optimiser. Reservoir performance was summarised in terms of reliability, resilience,
vulnerability and sustainability. The results show that the historic vulnerability reduced from
61 % (no hedging) to 20 % (with hedging), i.e., better than the 25 % vulnerability often
assumed tolerable for most water consumers. Climate change perturbations in the rainfall
produced the expected outcomes for the runoff, with higher rainfall resulting in more runoff
inflow and vice-versa. Reduced runoff caused the vulnerability to worsen to 66 % without
hedging; this was improved to 26 % with hedging. The fact that improved operational practices
involving hedging can effectively eliminate the impacts of water shortage caused by climate
change is a significant outcome of this study
Socio-economic parameters for impact assessment studies
Sorenson and McCreary defined coastal zone as the interface or transition
zone where part of the land is affected by its proximity to the sea and where part of
the ocean is affected by its proximity to the land in an area in which the processes
depending on the interaction between land and sea are more intense. The coastal
zone comprises a narrow strip of coastal low land and vast areas of coastal waters.
It constitutes 10 percent of the oceans but more than 50 percent of the oceans
biological productivity
Fruit and Vegetable Processing Sector in Bengal: Opportunities, Status and Challenges
Fruit and vegetable processing sector is one of the core segments under food processing in Bengal. Development of this sector is critically important to the expansion and diversification of stateтАЩs agricultural sector. It provides vital linkages and harnesses synergies between the two pillars of our economy, industry and agriculture. Bengal has huge potentials for the growth of this sector in the state. But such growth potentials are constrained by several factors. The processing of fruit and vegetable is still at a very low level in Bengal (2.8 per cent) as well as in India (2.2 per cent) against the highest post harvest losses (27 per cent). The main constraint lies behind this with infrastructure, technology, quality measurement and lack of farm-firm linkages. In view of the above facts this paper tries to examine the streangths of this particular sector in the state and highlighting on its existing constraints. The paper also made suggestions to achieve the future progress of this sector in Bengal
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