38 research outputs found
Looking for the Harappan Ports around Dholavira, Khadir Bet, Kachchh, Gujarat
1769-1773The rise of Harappan settlement at Dholavira is attributed to multidimensional factors which may include industrial activities, overseas trade and commerce and distribution of resources available in the Kachchh to other parts of the Harappan domain. The very location of the site is highly intriguing because presently the area is surrounded by marshy land which is called as Rann of Kachchh. However, various studies have indicated the different environmental and morphological conditions in the area and have been suggested that during Harappan time Rann was navigable. Though there is a remote possibility of any port installation close to ancient Dholavira town but a few potential sites in the proximity such as Jhandiasar, Saran and Bambhanka might have played a decisive role in the rise of Harappan settlement at Dholavira. The present study is based on the preliminary surface exploration undertaken in the recent past at above-mentioned sites
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The impact of monsoon intraseasonal variability on renewable power generation in India
India is increasingly investing in renewable technology to meet rising energy demands, with hydropower and other renewables comprising one-third of current installed capacity. Installed wind-power is projected to increase 5-fold by 2035 (to nearly 100GW) under the International Energy Agency’s New Policies scenario. However, renewable electricity generation is dependent upon the prevailing meteorology, which is strongly influenced by monsoon variability. Prosperity and widespread electrification are increasing the demand for air conditioning, especially during the warm summer.
This study uses multi-decadal observations and meteorological reanalysis data to assess the impact of intraseasonal monsoon variability on the balance of electricity supply from wind-power and temperature-related demand in India. Active monsoon phases are characterised by vigorous convection and heavy rainfall over central India. This results in lower temperatures giving lower cooling energy demand, while strong westerly winds yield high wind-power output. In contrast, monsoon breaks are characterised by suppressed precipitation, with higher temperatures and hence greater demand for cooling, and lower wind-power output across much of India. The opposing relationship between wind-power supply and cooling demand during active phases (low demand, high supply) and breaks (high demand, low supply) suggests that monsoon variability will tend to exacerbate fluctuations in the so-called demand-net-wind (i.e., electrical demand that must be supplied from non-wind sources).
This study may have important implications for the design of power systems and for investment decisions in conventional schedulable generation facilities (such as coal and gas) that are used to maintain the supply/demand balance. In particular, if it is assumed (as is common) that the generated wind-power operates as a price-taker (i.e., wind farm operators always wish to sell their power, irrespective of price) then investors in conventional facilities will face additional weather-volatility through the monsoonal impact on the length and frequency of production periods (i.e. their load-duration curves)
Network effects in two-sided markets: why a 50/50 user split is not necessarily revenue optimal
Effect of angiotensin-converting enzyme inhibitor and angiotensin receptor blocker initiation on organ support-free days in patients hospitalized with COVID-19
IMPORTANCE Overactivation of the renin-angiotensin system (RAS) may contribute to poor clinical outcomes in patients with COVID-19.
Objective To determine whether angiotensin-converting enzyme (ACE) inhibitor or angiotensin receptor blocker (ARB) initiation improves outcomes in patients hospitalized for COVID-19.
DESIGN, SETTING, AND PARTICIPANTS In an ongoing, adaptive platform randomized clinical trial, 721 critically ill and 58 non–critically ill hospitalized adults were randomized to receive an RAS inhibitor or control between March 16, 2021, and February 25, 2022, at 69 sites in 7 countries (final follow-up on June 1, 2022).
INTERVENTIONS Patients were randomized to receive open-label initiation of an ACE inhibitor (n = 257), ARB (n = 248), ARB in combination with DMX-200 (a chemokine receptor-2 inhibitor; n = 10), or no RAS inhibitor (control; n = 264) for up to 10 days.
MAIN OUTCOMES AND MEASURES The primary outcome was organ support–free days, a composite of hospital survival and days alive without cardiovascular or respiratory organ support through 21 days. The primary analysis was a bayesian cumulative logistic model. Odds ratios (ORs) greater than 1 represent improved outcomes.
RESULTS On February 25, 2022, enrollment was discontinued due to safety concerns. Among 679 critically ill patients with available primary outcome data, the median age was 56 years and 239 participants (35.2%) were women. Median (IQR) organ support–free days among critically ill patients was 10 (–1 to 16) in the ACE inhibitor group (n = 231), 8 (–1 to 17) in the ARB group (n = 217), and 12 (0 to 17) in the control group (n = 231) (median adjusted odds ratios of 0.77 [95% bayesian credible interval, 0.58-1.06] for improvement for ACE inhibitor and 0.76 [95% credible interval, 0.56-1.05] for ARB compared with control). The posterior probabilities that ACE inhibitors and ARBs worsened organ support–free days compared with control were 94.9% and 95.4%, respectively. Hospital survival occurred in 166 of 231 critically ill participants (71.9%) in the ACE inhibitor group, 152 of 217 (70.0%) in the ARB group, and 182 of 231 (78.8%) in the control group (posterior probabilities that ACE inhibitor and ARB worsened hospital survival compared with control were 95.3% and 98.1%, respectively).
CONCLUSIONS AND RELEVANCE In this trial, among critically ill adults with COVID-19, initiation of an ACE inhibitor or ARB did not improve, and likely worsened, clinical outcomes.
TRIAL REGISTRATION ClinicalTrials.gov Identifier: NCT0273570
Morpho-dynamic evolution of Ekakula spit of Odisha coast, India using satellite data
1157-1161Ekakula spit is at the northern end of Gahirmatha coast in the state of Odisha, India.
This spit is located at the mouth of Maipura river, which is falling in the northern
side of Mahanadi delta region. This spit is a
prominent and important for many reasons because it triggers interests to the
coastal managers and environmentalists because of its nature. Multi-temporal
satellite images (1999–2009) were used to study the Morpho-dynamic evolution of
this spit. Results show that the spit grows towards northeast mainly by the
deposition of sand brought by the littoral drift from the south. In the past,
it got fragmented and detached portion moved away towards the offshore. Temporal
satellite images revealed the progressive evolution of the spit. Spit appears
to have undergone growth and fragmentation over the years and accordingly the
Maipura river mouth shifted back and forth. The growth of the spit forces the
river to shift its mouth and the river causes the fragmentation by breaching
the spit during heavy floods. Ekakula spit lost about 306 m when compared its
position in 1973 (SOI toposheet) to the satellite image of 1999. The year-wise
length of the Ekakula spit was estimated using satellite data for the period
1999-2009 from a base point selected for this purpose. Ekakula spit length
increased since 1999 by 2710 m by 2008 and little reduced to 2431 m during
2008-2009. Spit appears to be growing steadily by the deposition of sediment
brought from south by the littoral drift except during 2003 and 2009 when it
suffered some erosion. Maximum increase in length was during 2004-2005 followed
by 2000-2001 and 1999-2000. Minimum was during 2004-2005. Erosion was minimal
during 2002-2003.</span
Impact of shipwrecks on the morphology of world coasts: A Review
1217-1223Role
of the grounded ship MV River Princess in activating erosion along the Candolim
to Sinquerim coast of Goa, India,
is evaluated. Beach and dune system was severely affected, as over a kilometre
long strip of coastal sand dunes were destroyed. Results suggest that the wreck
acted like an offshore breakwater, trapped sediment around the site, and
created a sediment deficit with consequent erosion south of the site. Coastal
retreat occurred at a rate of 7 to 8 m/year, over a period of 10 - 12 years,
along 1.5 km of sea front. A comparison of the impact of similar grounded
vessels around the globe confirms that shipwrecks in shallow seas have the
potential of drastically altering the face of the coast, often within a short
time. Major factors that determine the fate of the coast subsequent to a
shipwreck are: distance of the wreck from the shore, the depth of water, the
span of time when the wreck remains aground, the orientation of the vessel with
respect to the shore, the direction and intensity of prevailing winds, the
consequent wave regime, the resultant littoral currents and the disruption of
sediment transfer along the shore. The kind of short-term coastal erosion
witnessed in Goa as a consequence of a
marooned vessel appears unprecedented in comparison to similar examples found
worldwide.</span
Semantic Data Modeling using XML Schemas
Most research on XML has so far largely neglected the data modeling aspects of XML schemas. In this paper, we attempt to make a systematic approach to data modeling capabilities of XML schemas
Why were historical period ports of Goa located away from the coast? The decline of Gopakapatana
1357-1363Most
of the ports of the historical period of the east and west coasts of India were
located away from the seafront. But in later period, new ports were established
mostly along the coastal regions. The reasons attributed to abandoning inland
ports are: (a) bigger ships, which had to carry more cargo, (b) larger vessels
could withstand the flow of current, (c) advancement in shipbuilding and
navigation techniques, and (d) sediment deposition leading to navigational hazards.
In the case of Goa, Chandrapura (Chandor) was the oldest inland port. During
the later epoch, port activity shifted downstream to Gopakapatana, on the
northern bank of the River Zuari. During the 15th century AD, Old Goa, on the
bank of the Mandovi River, served as an important trade centre. Most modern
port in Goa was built at Mormugao in 1885 in the Zuari estuary. This paper
delineates the most likely cause for the decline of Gopakapatana, in
particular, as a trade centre, from a geo-historical and oceanographic
perspective. A detailed look into the evolution of the morphology of this river
bank reveals rapid accretion that led to the formation of a shallow feature. A
comparative study of maps of 1923, 1962-64, 2003 and modern images of 2010
confirm that the area is now occupied by a mud flat that extended by 68% during
the last 40 years.</span
Coastal vulnerability assessment of Puducherry coast, India, using the analytical hierarchical process
As a consequence of change in global climate, an increased frequency of natural hazards such as storm surges, tsunamis and cyclones, is predicted to have
dramatic affects on the coastal communities and ecosystems by virtue of the
devastation they cause during and after their occurrence. The tsunami of
December 2004 and the Thane cyclone of 2011 caused extensive human and
economic losses along the coastline of Puducherry and Tamil Nadu. The
devastation caused by these events highlighted the need for vulnerability
assessment to ensure better understanding of the elements causing different
hazards and to consequently minimize the after- effects of the future
events. This paper demonstrates an analytical hierarchical process (AHP)-based approach to coastal vulnerability studies as an improvement to the
existing methodologies for vulnerability assessment. The paper also
encourages the inclusion of socio-economic parameters along with the
physical parameters to calculate the coastal vulnerability index using AHP-derived weights. Seven physical–geological parameters (slope, geomorphology,
elevation, shoreline change, sea level rise, significant wave height and
tidal range) and four socio-economic factors (population,
land use/land cover (LU/LC), roads and location of tourist areas) are
considered to measure the physical vulnerability index (PVI) as well as the
socio-economic vulnerability index (SVI) of the Puducherry coast. Based on
the weights and scores derived using AHP, vulnerability maps are prepared to
demarcate areas with very low, medium and high vulnerability. A combination
of PVI and SVI values are further utilized to compute the coastal vulnerability index (CVI). Finally, the various coastal segments are grouped
into the 3 vulnerability classes to obtain the coastal vulnerability map.
The entire coastal extent between Muthiapet and Kirumampakkam as well as the
northern part of Kalapet is designated as the high vulnerability zone, which
constitutes 50% of the coastline. The region between the southern coastal
extent of Kalapet and Lawspet is the medium vulnerability zone and the remaining
25% is the low vulnerability zone. The results obtained enable the
identification and prioritization of the more vulnerable areas of the region in order to further
assist the government and the residing coastal communities in better coastal
management and conservation
Shoreline changes along Tamil Nadu coast: A study based on archaeological and coastal dynamics perspective
1167-1176Available
geophysical survey data confirm submergence of a large area comprising of
building complex, which are possible remains of a submerged township. A global
sea level rise estimate of 1-2 mm per year would inundate up to several hundred
meters of coast line over a period of 2000 years. Shore line changes have been
calculated to about 497 m and 380 m at Poompuhar and Tranquebar during the last
75 years. Apart from prevailing waves
and currents, past sea level change estimates, tectonic movement induced
subduction, erosion from storms and palaeo-tsunamis events, are plausible
reasons for the shoreline retreat. It can be said that the coastal erosion due
to invasion of sea has played a major role in submergence of these structures.
The present paper deals with the shoreline retreat estimates resulting from
underwater explorations, past sea level changes and extreme events along the
Tamil Nadu coast. </span