338 research outputs found
Introduction to geostatistics
Geographical Information System (GIS) is a technological tool used to describe and
characterize spatially referenced geographical information for the purpose of visualizing,
querying and analyzing. The tool enables capturing, storing, analyzing, sharing, displaying
and modelling of spatial data maintained with in single database. Making decision based
on geography is basics to human thinking and spatial analysis using GIS enable people to
combine information from many independent sources and derive entirely new layers of
information that are more accurate and reliable in decision making. Spatial analysis involves
study of phenomenon that varies with time and space
Design and analysis of contour bell nozzle and comparison with dual bell nozzle
The performance and the thrust delivery of the engine such as nozzles are in renovation for the greater performance. Modern combustion expansion system like in rocket nozzles will be updated with respect to the application. Bell and Dual bell nozzle is the One of such development. Four different types of Bell nozzle one duel bell nozzle is selected and studied using computational fluid dynamics (CFD) in the present paper. The project mainly focuses on design and analysis of contoured convergent divergent bell nozzle. For the simulation, consider ┬аa 2D , parabolic contoured thrust optimized axisymmetric nozzle. The priority is ┬аgiven to design a bell nozzle with negligible shock wave. The temperature effects are not taken into this study, the flow is purely cold flow (303K). A full length Bell nozzle created using Gambit software. The meshing and analysis of the Bell model were done using FLUENT software. Air is taken as working medium for the nozzle and also for the ambience. Only one half of the nozzle is simulated due to symmetry reasons, and symmetry boundary conditions are used at the corresponding planes. The nozzle walls were set as adiabatic and assumed to be hydraulically smooth. A control volume was constructed around the nozzle to take the interaction with the ambience. The behavior of flow along the bell nozzle is thus obtained
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Techno-Economic Analysis of Hybrid Layered Manufacturing
Subtractive manufacturing (CNC machining) has high quality of geometric and
material properties but is slow, costly and infeasible in some cases; additive
manufacturing (RP) is just the opposite. Total automation and hence speed is
achieved in RP by compromising on quality. Hybrid Layered Manufacturing
(HLM) developed at IIT Bombay combines the best features of both these
approaches. It uses arc welding for building near-net shapes which are finish
machined to final dimensions. High speed of HLM surpasses all other processes
for tool making by eliminating NC programming and rough machining. The
techno-economic viability of HLM process has been proved through a real life
case study. Time and cost of tool making using HLM promises to be substantially
lower than that of CNC machining and other RP methods. Interestingly, the
material cost in HLM was also found to be lower. HLM is a cheaper retrofitment
to any 3 or 5 axis CNC milling machine or machining center.Mechanical Engineerin
Scale worm recorded from Lakshadweep
During an underwater survey in lagoon of Chetlat
island Lakshdweep in 2015 a cryptic, commensalistic
scale worm association on the sea cucumber
Stichopus chloronotus was observed. This scale
worm was identified as Gastrolepidia clavigera
Schmarda, 1861 which come under polychaetes
(Family:Polynoidae). These are known to inhabit the
surface of holothurians in its anterior or posterior
ends, and if disturbed crawl into the mouth or cloaca
of the sea cucumber. The colour of the scale worm
mimics the colour of the host which makes it
difficult to be detected. Studies have found that
this scale worm species feed on the tissue of the
sea cucumber and are resistant to the toxin
holothurin which is commonly released by sea
cucumbers against predators
тАШPakshi PittiтАЩ: a robust haven for pelagic birds in the Indian Ocean
India, a land of distinct climatic and geographic zones,
supports a remarkable diversity of avian fauna within both
its mainland and its seas. There are over 1200 species of
birds recorded in India, with the majority occurring in
the mainland (Praveen et al., 2016). Surrounded by extensive
marine zones on its three sides, territorial waters and
marginal seas around India form seamless habitats for a
significant number of marine avian species. Seventy species
of marine birds are observed in the region (BirdLife
International 2015). These include predominantly open
oceanic species like frigate birds, tropicbirds, shearwaters
and petrels which are winter visitors or vagrants, but birds
like gulls and terns are more commonly found along the
coastal waters of India
Species distribution modelling of seaweeds in Indian Seas
Seaweeds, the green pastures of the ocean, hold immense potential for IndiaтАЩs coastal communities and its burgeoning blue economy. These marine macroalgae are not just
ecological keystones, responsible for oxygen production and forming the base of marine food webs, but also a multi-billion-dollar industry offering a cornucopia of products, from food supplements to hydrocolloids. With projections for exponential growth in the coming decades, harnessing the potential of seaweeds requires precise and sustainable approaches. While India stands strong as a seaweed cultivating nation, identifying suitable regions for this
marine bounty remains a complex puzzle. The vast and diverse coastline demands advanced tools to unlock hidden opportunities. The realm of species distribution modelling (SDM) aids in identifying the suitable habitats along our coast. This book chapter offers a comprehensive
exploration of how SDM can illuminate the path for a thriving seaweed industry in India. Through a real-world case study of an SDM exercise, we paint a vivid picture of how this technology can translate knowledge into action
Rough triggerfish, Canthidermis maculata from Gujarat coast
A specimen of the Rough triggerfish,
Canthidermis maculata (Bloch, 1786) was landed
by a multiday trawler on 25th November 2015 at
Mangrol Fisheries Harbour, Gujarat. The specimen
was brownish grey in colour with characteristic
white spots all over the body including the head. It
measured 309 mm and 256 mm in Total length and
Standard length respectively with a weight of 580 g
(Fig. 1). The fish is usually found in areas having
sandy, muddy or rocky bottoms at a depth range of
50-100 m and is reported from the Western Indian
Ocean
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Plankton Productivity in Lagoons of Agatti and Bangaram Atolls of Lakshadweep Archipelago, India
Phytoplankters and zooplankters function as important
links in the food chain and form the food of
a large number of organisms in the aquatic
ecosystem. As plankters play an important role in
the health of an aquatic ecosystem, the study on
these resources in the productive aquatic ecosystems
of Lakshadweep is significant. Earlier studies
carried out earlier from Agatti and Bangaram are by
Pratap et al. (1977), Achuthankutty et al. (1989) and
Casanova & Nair (1999). No recent reports are
available on plankters from Agatti and Bangaram.
Hence, an attempt is made to study the qualitative
and quantitative abundance of phytoplankters and
zooplankters in the selected lagoons of Lakshadweep
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