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1.
N. V. Madhu R. Jyothibabu K. K. Balachandran 《Environmental monitoring and assessment》2010,166(1-4):521-528
Changes in the autotrophic pico- (0.2–2 μm), nano- (2–20 μm), and microplankton (>20 μm) biomass (chlorophyll a) and primary production were measured in the estuarine and coastal waters off Cochin, southwest coast of India during the onset and establishment of a monsoon. During this period, the estuary was dominated by nutrient-rich freshwater, whereas the coastal waters were characterized with higher salinity values (>30 psu) and less nutrients. The average surface chlorophyll a concentrations and primary production rates were higher in the estuary (average 13.7 mg m???3 and 432 mgC m???3 day???1) as compared to the coastal waters (5.3 mg m???3 and 224 mgC m???3 day???1). The nanoplankton community formed the major fraction of chlorophyll a and primary production, both in the estuary (average 85 ± SD 8.3% and 81.2 ± SD 3.2%) and the coastal waters (average 73.2 ± SD 17.2% and 81.9 ± 15.7%). Nanoplankton had the maximum photosynthetic efficiency in the coastal waters (average 4.8 ± SD 3.9 mgC mgChl a m???3 h???1), whereas in the estuary, the microplankton had higher photosynthetic efficiency (average 7.4 ± 7 mgC mgChl a m???3 h???1). The heavy cloud cover and increased water column turbidity not only limit the growth of large-sized phytoplankton in the Cochin estuary and coastal waters but also support the proliferation of nanoplankton community during the monsoon season, even though large variation in nanoplankton chlorophyll a and production exists between these two areas. 相似文献
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Kusum Komal Karati G. Vineetha N. V. Madhu P. Anil M. Dayana B. K. Shihab A. I. Muhsin C. Riyas T. V. Raveendran 《Environmental monitoring and assessment》2017,189(12):653
El Niño, an interannual climate event characterized by elevated oceanic temperature, is a prime threat for coral reef ecosystems worldwide, owing to their thermal threshold sensitivity. Phytoplankton plays a crucial role in the sustenance of reef trophodynamics. The cell size of the phytoplankton forms the “master morphological trait” with implications for growth, resource acquisition, and adaptability to nutrients. In the context of a strong El Niño prediction for 2015–2016, the present study was undertaken to evaluate the variations in the size-structured phytoplankton of Kavaratti reef waters, a major coral atoll along the southeast coast of India. The present study witnessed a remarkable change in the physicochemical environment of the reef water and massive coral bleaching with the progression of El Niño 2015–2016 from its peak to waning phase. The fluctuations observed in sea surface temperature, pH, and nutrient concentration of the reef water with the El Niño progression resulted in a remarkable shift in phytoplankton size structure, abundance, and community composition of the reef waters. Though low nutrient concentration of the waning phase resulted in lower phytoplankton biomass and abundance, the diazotroph Trichodesmium erythraeum predominated the reef waters, owing to its capability of the atmospheric nitrogen fixation and dissolved organic phosphate utilization. 相似文献
3.
Chenniappan Thiagarajan Subbaiyan Naveen Sundaram Madhu Perumal Muthumari 《环境质量管理》2023,32(4):317-326
Multiple ecological tactics, like the ones described here, can be imitated to strongly affect these two components in the construction sector. This article provides an in-depth examination of the literature on biomimicry-based strategies intended to enhance building designs. This analysis is motivated by the rising need for energy legislation to achieve future local goals and provide a framework for use in Panama. These biomimicry-based methods have undergone more review and evaluation, and the incorporation of organism-based design for three of Panama's climate types has been proposed. Therefore, a SWOT analysis assisted in realizing the full potential that biomimicry-based techniques might have in raising the likelihood of satisfying local and international regulatory standards. In order to design constructions using biomimicry, multidisciplinary collaboration is required. This gives a competitive edge for better-trained human resources and expands horizons in the conventional construction industry. Finally, the analysis provided here might act as the preliminary step for the additional technical assessment using numerical and experimental procedures. 相似文献
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A carbon tax on fuel would penalize carbon intensive fuels like gasoline and shift fuel consumption to less carbon intensive alternatives like biofuels. Since biofuel production competes for land with agricultural production, a carbon tax could increase land rents and raise food prices. This paper analyzes the welfare effect of a carbon tax on fuel consisting of gasoline and biofuel in the presence of a labor tax, with and without a biofuel subsidy. The market impacts of a carbon tax are also compared with that of a subsidy. Findings show that if a carbon tax increases biofuel demand, the tax interaction effect due to higher fuel prices is exacerbated by higher land rent and food prices and greater erosion of the carbon tax base. Thus, the second best optimal carbon tax for fuel is lower with biofuel in the fuel mix, especially if biofuel is subsidized. 相似文献
7.
Madhu Ramnath 《Natural resources forum》2001,25(3):245-256
This article enters the debate on shifting cultivation and tropical forests, and the role of the State forest departments in managing these regions. The article focuses on the adivasi (indigenous) people and their use of forests in the Bastar region of Madhya Pradesh in Central India. It examines the different landscapes, resulting from human interaction, in order to observe the vegetative changes and progressions in their characteristics; in particular, the author challenges the view that adivasi forest use has been detrimental to the ecology of the forest. A botanical comparison is made between three sites that allow us to note specific characteristics of a fallow, a secondary forest and a primary sal (Shorea robusta) forest. The wider aspects of the adivasi manner of forest use are also discussed.
A major portion of the Bastar region is legally under the authority of the Madhya Pradesh State Forest Department. However, the official policies and laws, pertaining to the conservation of forests and the generation of revenue, are often insensitive to the adivasi perceptions and use of the various vegetative zones within the forest. The effect of a standardised form of demarcation, coupled with the State legislation, has overlooked the adivasi people's needs and their ecologically sound way of relating to the forest. The paper concludes with a few recommendations. 相似文献
A major portion of the Bastar region is legally under the authority of the Madhya Pradesh State Forest Department. However, the official policies and laws, pertaining to the conservation of forests and the generation of revenue, are often insensitive to the adivasi perceptions and use of the various vegetative zones within the forest. The effect of a standardised form of demarcation, coupled with the State legislation, has overlooked the adivasi people's needs and their ecologically sound way of relating to the forest. The paper concludes with a few recommendations. 相似文献
8.
Madhu Ramnath 《Natural resources forum》1997,21(4):257-271
This article inserts itself into the ongoing debate over the changing role of State Forest Departments from the traditional task of obtaining revenue for the State through extracting timber and sale of minor forest products, to the emerging identity of protector of wildlife and biodiversity of the forest environment. The article focusses on the adivasi (indigenous) people in the Bastar region of Madhya Pradesh in Central India. It highlights how market forces, regional politics and official conservation policies adversely affect the adivasi people, who inhabit these forests and gain their livelihood from them. Ironically, efforts intended to conserve and protect in many instances instead contribute to increased pressure on the forest.
Major portions of the forests in the region are officially under the authority of the State Forest Department, and many of the adivasi traditional activities, necessary to their livelihood, have been curtailed by law. The article discusses the various areas of conflict/dialogue between the adivasi and the authorities, and the different perceptions of forest space versus land rights. The vegetation of the area and local usage of non-timber forest products are central themes of the article . 相似文献
Major portions of the forests in the region are officially under the authority of the State Forest Department, and many of the adivasi traditional activities, necessary to their livelihood, have been curtailed by law. The article discusses the various areas of conflict/dialogue between the adivasi and the authorities, and the different perceptions of forest space versus land rights. The vegetation of the area and local usage of non-timber forest products are central themes of the article . 相似文献
9.
Gautam R. Eapi Madhu S. Sabnis 《Journal of the Air & Waste Management Association (1995)》2014,64(8):927-944
Production of natural gas from shale formations is bringing drilling and production operations to regions of the United States that have seen little or no similar activity in the past, which has generated considerable interest in potential environmental impacts. This study focused on the Barnett Shale Fort Worth Basin in Texas, which saw the number of gas-producing wells grow from 726 in 2001 to 15,870 in 2011. This study aimed to measure fence line concentrations of methane and hydrogen sulfide at natural gas production sites (wells, liquid storage tanks, and associated equipment) in the four core counties of the Barnett Shale (Denton, Johnson, Tarrant, and Wise). A mobile measurement survey was conducted in the vicinity of 4788 wells near 401 lease sites, representing 35% of gas production volume, 31% of wells, and 38% of condensate production volume in the four-county core area. Methane and hydrogen sulfide concentrations were measured using a Picarro G2204 cavity ring-down spectrometer (CRDS). Since the research team did not have access to lease site interiors, measurements were made by driving on roads on the exterior of the lease sites. Over 150 hr of data were collected from March to July 2012. During two sets of drive-by measurements, it was found that 66 sites (16.5%) had methane concentrations >3 parts per million (ppm) just beyond the fence line. Thirty-two lease sites (8.0%) had hydrogen sulfide concentrations >4.7 parts per billion (ppb) (odor recognition threshold) just beyond the fence line. Measured concentrations generally did not correlate well with site characteristics (natural gas production volume, number of wells, or condensate production). t tests showed that for two counties, methane concentrations for dry sites were higher than those for wet sites. Follow-up study is recommended to provide more information at sites identified with high levels of methane and hydrogen sulfide.
Implications:Information regarding air emissions from shale gas production is important given the recent increase in number of wells in various regions in the United States. Methane, the primary natural gas constituent, is a greenhouse gas; hydrogen sulfide, which can be present in gas condensate, is an odor-causing compound. This study surveyed wells representing one-third of the natural gas production volume in the Texas Barnett Shale and identified the percent of sites that warrant further study due to their fence line methane and hydrogen sulfide concentrations. 相似文献
10.
Periyayya Uthirakumar Madhu Devendiran Subramaniyam Kalaiarasan Son Hoki Lee In-Hwan 《Environmental science and pollution research international》2021,28(6):6459-6469
Environmental Science and Pollution Research - A simple oxidation method for preparing CuO nanodisks on a flexible Cu sheet is presented. The crystal structure of as-prepared CuO nanodisks was... 相似文献