Recursos de colección

ETD at Indian Institute of Science (3.494 recursos)

Repository of Theses and Dissertations of Indian Institute of Science, Bangalore, India. The repository has been developed to capture, disseminate and preserve research theses of Indian Institute of Science.

Centre for Sustainable Technologies (formerly known as ASTRA) (astra)

Mostrando recursos 1 - 19 de 19

  1. Vulnerability of Forests to Climatic and Non-Climatic Stressors : A Multi-Scale Assessment for Indian Forests

    Sharma, Jagmohan
    During the 21st century, climatic change and non-climatic stressors are likely to impact forests leading to large-scale forest and biodiversity loss, and diminished ecological benefits. Assessing the vulnerability of forests and addressing the sources of vulnerability is an important risk management strategy. The overall goal of this research work is to develop methodological approaches at different scales and apply them to assess the vulnerability of forests in India for developing strategies for forest adaptation. Indicator-based methodological approaches have been developed for vulnerability assessment at local, landscape and national scales under current climate scenario, and at national scale under future climate scenario....

  2. Effect of Extractives and Crude Proteins on the Kinetics of Hydrolysis in a Solid State Bio-Reactor

    Ravi Kumar, D
    Polymer hydrolysis is the first (and rate limiting) step for biomethanation of heterogeneous biomass feedstock’s. Satisfactory hydrolysis has been difficult to achieve, understand and predict adequately, to run anaerobic bioreactors with such feedstock’s efficiently. The fraction of hot water soluble extracts (crude proteins and extractables, Fcpe), the nature and material of intercellular binding and the extent and complexity of lignin present have been considered as key parameters for hydrolysis and has been analyzed for a variety of biomass degradation data available at the Centre for Sustainable Technologies, Indian Institute of Science. Feedstocks were grouped into those bound with high levels...

  3. Studies on Modified Clay Additives to Impart Iodide Sorption Capacity to Bentonite in the Context of Safe Disposal of High Level Nuclear Waste

    Sivachidambaram, S
    It is a generally agreed internationally that high level nuclear wastes containing long-lived radioactive wastes should be disposed in deep and stable geological formations that are 500-1000 m below ground level. Deep geological disposal is based on the concept of multiple barriers to prevent deep ground-waters, present in almost all rock formations, from rapidly leaching the wastes and transporting radioactivity away from the repository. The multiple barrier system comprises of ‘engineered barriers’ that are constructed in the repository and ‘natural barriers’ in the surrounding geological environment. The engineered barrier components comprise of the vitrified solid waste, canister (to contain the...

  4. Studies into Thermal Transmittance of Conventional and Alternative Building Materials and Associated with Building Thermal Performance

    Balaji, N C
    The present investigation is focused on the thermal performance of building materials, specifically their thermal transmittance, and consequent impact on building envelope and building thermal performance. Thermal performance of building materials plays a crucial role in regulating indoor thermal comfort when suitably integrated as part of the building envelope. Studies into thermal performance of building materials are few, particularly in the context of designing building blocks to achieve a particular thermal transmittance in buildings. Such studies require both theoretical (numerical) investigations augmented with experimental investigation into material thermal performance. A unique contribution of this study has been assessing the temperature-dependent...

  5. Reliability Based Approach for Evaluation of MSW Landfill Designs and Site Selection using GIS

    Santhosh, L G
    Dumping of municipal solid waste (MSW) generated due to anthropogenic activities in any barren land or out fields causes severe hazards to human populations, ecosystems and the environment. In order to avoid this, it is required to design landfills in an engineered and scientific manner. Therefore, it is necessary to understand the behaviour of landfills over a period of time, to design landfills for site specific conditions. In this thesis such an attempt is made to evaluate performance of conventional landfill system using a large scale anaerobic reactor in the laboratory. The performance of the containment (bottom liner and final...

  6. Expermental and Modeling Studies on the Generation of Hydrogen Rich Syngas through Oxy-Steam Gasification of Biomass

    Sandeep, Kumar
    The present work focuses on the study of biomass gasification process for generating hydrogen rich synthetic gas with oxy-steam as reactants using experiments and modeling studies. Utilization of the syngas as a fuel in general applications like fuel cells, Fischer-Tropsch FT) process and production of various chemicals like DME, etc. are being considered to meet the demand for clean energy. This study comprises of experiments using an open top down draft reactor with oxygen and steam as reactants in the co-current configuration. Apart from the standard gasification performance evaluation; parametric study using equivalence ratio, steam-to-biomass ratio as major variables towards...

  7. Granular Media Supported Microbial Remediation of Nitrate Contaminated Drinking Water

    Malini, R
    Increasing nitrate concentration in ground water from improper disposal of sewage and excessive use of fertilizers is deleterious to human health as ingestion of nitrate contaminated water can cause methaemoglobinemia in infants and possibly cancer in adults. The permissible limit for nitrate in potable water is 45 mg/L. Unacceptable levels of nitrate in groundwater is an important environmental issue as nearly 80 % of Indian rural population depends on groundwater as source of drinking water. Though numerous technologies such as reverse osmosis, ion exchange, electro-dialysis, permeable reactive barriers using zero-valent iron exists, nitrate removal from water using affordable, sustainable technology,...

  8. Integrability Evaluation Methodology for Building Integrated Photovoltaic's (BIPV) : A Study in Indian Climatic Conditions

    Eranki, Gayathri Aaditya
    India’s geographical location renders it with ample solar-energy potential ranging from 4-7 kWh/m2 daily and 2,300–3,200 sunshine hours annually. The diverse nature of human settlements (scattered low-rise to dense high-rise) in India is one of the unexplored avenues of harnessing solar energy through electricity generation using photovoltaic (PV) technology. Solar energy is a promising alternative that carries adequate potential to support the growing energy demands of India’s burgeoning population. A previous study estimates, by the year 2070, with 425 million households (of which utilizing only 20 %), about 90 TWh of electrical energy can be generated utilizing solar energy. PV...

  9. Integrability Evaluation Methodology for Building Integrated Photovoltaic's (BIPV) : A Study in Indian Climatic Conditions

    Eranki, Gayathri Aaditya
    India’s geographical location renders it with ample solar-energy potential ranging from 4-7 kWh/m2 daily and 2,300–3,200 sunshine hours annually. The diverse nature of human settlements (scattered low-rise to dense high-rise) in India is one of the unexplored avenues of harnessing solar energy through electricity generation using photovoltaic (PV) technology. Solar energy is a promising alternative that carries adequate potential to support the growing energy demands of India’s burgeoning population. A previous study estimates, by the year 2070, with 425 million households (of which utilizing only 20 %), about 90 TWh of electrical energy can be generated utilizing solar energy. PV...

  10. Algal Bioprocess Development for Sustainable Wastewater Treatment and Biofuel Production

    Mahapatra, Durga Madhab
    Rapid urbanization has led to the generation of enormous wastewater after independence. The domestic wastewater generated in municipalities is rich in nutrients such as carbon, nitrogen and phosphorus along with other ions. The generated wastewater due to lack of adequate appropriate infrastructure including low treatment efficiencies are either untreated or partially treated and are let into water bodies. Present sewage treatment plants (STP’s) in the city are either under capacity or malfunctioning and hence are unable to meet the growing demand of burgeoning urban population. Water bodies have the ability to uptake nutrients (remediation by algae, bacteria, macrophytes) provided the...

  11. Algal Bioprocess Development for Sustainable Wastewater Treatment and Biofuel Production

    Mahapatra, Durga Madhab
    Rapid urbanization has led to the generation of enormous wastewater after independence. The domestic wastewater generated in municipalities is rich in nutrients such as carbon, nitrogen and phosphorus along with other ions. The generated wastewater due to lack of adequate appropriate infrastructure including low treatment efficiencies are either untreated or partially treated and are let into water bodies. Present sewage treatment plants (STP’s) in the city are either under capacity or malfunctioning and hence are unable to meet the growing demand of burgeoning urban population. Water bodies have the ability to uptake nutrients (remediation by algae, bacteria, macrophytes) provided the...

  12. Autoflocculating Mixotrophic Algal Consortia Approach to Sustainable Wastewater Treatement

    Krupa, D
    The phenomenon of rapid algal blooms in response to nutrient overloads has been adapted to treat synthetic domestic wastewater. Various algal consortia collected from several eutrophied water bodies were subject to high density algal culture (upto 106-107 cells/mL) and screened for rapid algal growth, pollutant removal, nutrient recovery under mixotrophy and auto-flocculation. When tried in laboratory scale algal ponds, these algal consortia showed growth rates between 0.15 and 1.07 d-1. Results indicate that Chlorella occurred frequently among most consortia although not always the largest in number. While individual algal species varied in growth rates among these consortia, the log phase...

  13. Autoflocculating Mixotrophic Algal Consortia Approach to Sustainable Wastewater Treatement

    Krupa, D
    The phenomenon of rapid algal blooms in response to nutrient overloads has been adapted to treat synthetic domestic wastewater. Various algal consortia collected from several eutrophied water bodies were subject to high density algal culture (upto 106-107 cells/mL) and screened for rapid algal growth, pollutant removal, nutrient recovery under mixotrophy and auto-flocculation. When tried in laboratory scale algal ponds, these algal consortia showed growth rates between 0.15 and 1.07 d-1. Results indicate that Chlorella occurred frequently among most consortia although not always the largest in number. While individual algal species varied in growth rates among these consortia, the log phase...

  14. Assessment of Environmental Issues And Biodegradation Aspects of Current MSW Practices of Developing Country Metropolises - A Case Study of Bangalore

    Shwetmala, *
    Municipal solid waste (MSW) production has significantly increased in the rapidly urbanizing developing world and also changed composition with increased decomposable organic fraction in MSW (OFMSW) and plastics content. This has stressed the environment in many ways while city managers and citizens have responded with various technological and management solutions leading to a need for scientific, environmental, technological and sustainability assessments of the emerging problems. This sets the research agenda and framework for this study wherein the MSW generation, composition, processing and treatment methods, open dumping practices, environmental liability, natural degradation, sustainability issues etc. have been studied for the city...

  15. Assessment of Environmental Issues And Biodegradation Aspects of Current MSW Practices of Developing Country Metropolises - A Case Study of Bangalore

    Shwetmala, *
    Municipal solid waste (MSW) production has significantly increased in the rapidly urbanizing developing world and also changed composition with increased decomposable organic fraction in MSW (OFMSW) and plastics content. This has stressed the environment in many ways while city managers and citizens have responded with various technological and management solutions leading to a need for scientific, environmental, technological and sustainability assessments of the emerging problems. This sets the research agenda and framework for this study wherein the MSW generation, composition, processing and treatment methods, open dumping practices, environmental liability, natural degradation, sustainability issues etc. have been studied for the city...

  16. Experiments And Analysis on Wood Gasification in an Open Top Downdraft Gasifier

    Mahapatra, Sadhan
    The thesis, through experimental and numerical investigations reports on the work related to packed bed reactors in co-current configuration for biomass gasification. This study has extensively focused on the gasification operating regimes and addressing the issues of presence of tar, an undesirable component for engine application. Systematically, the influence of fuel properties on the gasification process has been studied using single particle analysis and also in packed bed reactors. Studies related to the effect of fuel properties - size, surface area volume ratio and density on the reactor performance are addressed. The influence of these parameters on the propagation rate which...

  17. Experiments And Analysis on Wood Gasification in an Open Top Downdraft Gasifier

    Mahapatra, Sadhan
    The thesis, through experimental and numerical investigations reports on the work related to packed bed reactors in co-current configuration for biomass gasification. This study has extensively focused on the gasification operating regimes and addressing the issues of presence of tar, an undesirable component for engine application. Systematically, the influence of fuel properties on the gasification process has been studied using single particle analysis and also in packed bed reactors. Studies related to the effect of fuel properties - size, surface area volume ratio and density on the reactor performance are addressed. The influence of these parameters on the propagation rate which...

  18. Distributed Bioenergy Systems For Expanding Rural Electricity Access In Tumkur District, India : A Feasibility Assessment Using GIS, Heuristics And Simulation Models

    Deepak, P
    Energy is an important input for various activities that provide impetus to economic, human and social development of any country. Among all the energy carriers, electricity is the most important and sought after energy carrier for its quality, versatility and ability to perform various technology driven end-use activities. Therefore access to electricity is considered as the single most important indicator determining the energy poverty levels prevailing in a country. Demand for electricity has increased significantly, especially in the developing countries, in recent years due to growth in population and intensification of economic activities. Therefore, providing quality and reliable electricity supply at low-cost...

  19. Activation Of Fly Ash-Lime Reactions By Curing At Elevated Temperature And By Addition Of Phosphogypsum

    Asha, K
    Pozzolanic reactions play a key role in improving the compressive strengths of compacted fly ash-lime specimens. Based on studies performed with cement amended fly ash (FA), activation of fly ash-lime pozzolanic reactions should accelerate the rate of strength development and mobilize larger compressive strengths facilitating improved engineering performance of fly ash amended materials. Further, use of phosphogypsum (PG) is a cause of environmental concern as the material is acidic (pH < 3.0) and contains considerable amounts of fluoride (0.86%). The main research objectives of the thesis are to activate lime-fly ash reactions by thermal and chemical activation process and examine...

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