5 research outputs found
Examining evaporative demand and water availability in recent past for sustainable agricultural water management in India at sub-basin scale
This study explores recent changes in evaporative demand and water availability across 100 river sub-basins in India by partitioning the actual evapotranspiration (AET) into green water evapotranspiration (ET-Green) and blue water evapotranspiration (ET-Blue). For computation of ET-Green and ET-Blue, the Budyko framework is applied to long-term scenario (2003–2017) and to intra-annual averaged series (i.e. 2003-2007, 2008–2012 and 2013–2017). For the Budyko analysis, the Climate Hazards Group InfraRed Precipitation with Station data (CHIRPS), Global Land Data Assimilation System (GLDAS) AET and Climate Research Unit Global Data Assimilation System (CRU GDAS) Potential ET (PET) climate forcing variables have been utilized. Multiple hydro-climatic indicators, such as dryness index (DI), evaporative index (EI), and responsivity with respect to theoretical Budyko curve are computed and they show substantial variations across sub-basins from far past time (2003) to recent past (2017). The changes in DI and EI highlight the diversity in evaporative demand and dryness condition across the country. Results reveal that India's evaporative water demand is largely influenced by ET-Green (up to 65%) that depends mainly on precipitation. At the same time, in many river sub-basins, ET-Blue that depends on external sources of water like diversion or stored water, is significant. The shape parameter (ω) of Fu's Budyko equation, that can be utilized for the future assessment of ET-Green and ET-Blue, has been optimized. The results of this study would of immense value for sustainable irrigation water management and improving water use efficiency in agriculture and overall water availability in river basins in India.Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Water Resource
Fuzzy logic based active vibration control using novel photostrictive composites
Although conventional actuators like piezoelectric and electrostrictive are efficient, but they required hard wiring, which contaminates the control signal and adds to the weight of the structure. The current study presents a wireless control strategy using photostrictive actuators. Owing to the fortunate combination of photovoltaic effect and converse piezoelectric effect, a photostrictive actuator can generate mechanical strain, when irradiated with light intensity. Limited choices of photostrictive material with high electromechanical coupling coefficient give the motivation to design photostrictive composites. The finite element-based formulation incorporating fuzzy logic controller is employed to study the active vibration control response of cantilever structure when equipped with photostrictive composite actuator. A parametric study has been carried out to study the influence of inclusion's volume fraction on wireless active vibration control of the structure. Control merits have been defined to compare the control performance of different composites. It is found that particulate composites are the better choice for lightweight structure and fiber composites are better if there is no weight constraint.Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Transport Engineering and Logistic
Extended Isogeometric Analysis of Cracked Piezoelectric Materials in the Presence of Flexoelectricity
To accurately analyze the fracture behavior of piezoceramics at small length scales, flexoelectricity must be considered along with piezoelectricity. Due to its dependence on size, flexoelectricity predominates at the micro- and nano-length scales. Additionally, crack tips having the largest strain gradient state cause large flexoelectricity around them. Different approaches are employed in the past to model cracks computationally. However, extended isogeometric analysis (XIGA) is proven to be an accurate and efficient method. C1 continuity requirements for modeling gradients in flexoelectricity are met by non-uniform rational B-splines (NURBS) basis functions used in XIGA. In this work, XIGA-based computational model is developed and implemented to study the fracture behavior of the piezoelectric-flexoelectric domain. An in-house MATLAB code is developed for the same. Several numerical examples are studied to ensure the efficacy and efficiency of the implemented model, and crack behavior is presented in the form of an electro-mechanical J-integral. The analysis is carried out to investigate how cracks behave for different flexoelectric coefficients under different electrical and mechanical loading combinations. J-integral is also analyzed against crack parameters such as crack orientation and length. It is observed that boundary loads and flexoelectric material constants significantly influence J-integral. Results also show a considerable amount of fracture toughening in the presence of flexoelectricity. The peak value of J-integral is found to be reduced with an increase in the flexoelectric coefficient. A significant reduction in J-integral, as much as 45%, is observed when the flexoelectric constant varied from 0.5 to 2 µCm−1.Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Transport Engineering and Logistic
Optimal source-sink matching and prospective hub-cluster configurations for CO2 capture and storage in India
At COP-26, India announced strong climate commitments of reaching net-zero greenhouse gas emissions by 2070. Meeting this target would likely require substantial deployment of CO2 capture and storage (CCS) to decarbonize existing large point sources of CO2. This study attempts to evaluate opportunities for deployment of CCS in India in the forthcoming decades. A GIS based approach was adopted for mapping existing sources of CO2 with the sinks. The results show that regionally-appropriate ways of moving towards CCS at scale exist in both the power and industrial sectors. Coupled analysis of these sectors with sinks shows that 8 clusters may be developed throughout the country to sequester 403 Mt-CO2 annually. These clusters are concentrated near Category-I oil basins and the Category-I coalfields (Damodar valley), which may also create suitable financial incentives by incremental oil and coalbed methane recovery respectively. Furthermore, a first-order costing analysis evaluates that the cost of avoidance across basins may range from 107/t-CO2, depending on the type of storage reservoir and the proximity to large point sources. A total of 12 suitable hubs and clusters were created based on annual emissions above 1 Mt of each large point source and their proximity with geological sinks.Accepted Author ManuscriptApplied Geophysics and Petrophysic
Pore morphology in thermally-treated shales and its implication on CO<sub>2</sub> storage applications: A gas sorption, SEM, and small-angle scattering study
A combination of high-resolution imaging, low-pressure gas adsorption, and small-angle X-ray and neutron scattering quantifies changes in the pore characteristics of pulverized shale samples under oxic and anoxic environments up to 300 ℃. Clay-rich early-mature shales have a fair potential to generate hydrocarbons, the total organic carbon content of which lies within a range of 2.9 % to 7.4 %. High-resolution imaging indicates restructuring and coalescence of Type III kerogen-hosted pores due to oxic heating, which causes up to 580 % and 300 % increase in the surface area and pore volume of mesopores respectively. Similarly, up to 300 % and 1200 % increase in micropore surface area and pore volume is observed post oxic heating. However, during anoxic heating, bitumen mobilizes, leads to pore-blockage, and reduces the surface area and pore volume up to 45 % and 12 % respectively without any significant mass loss up to 350 °C. Between 400 and 550 °C, considerable loss in mass occurred due to breaking of organic matter, facilitated by the presence of siderite that caused up to 30 % loss in mass. The test conditions display starkly opposite effects in pores that have a width of < 100 nm when compared to the larger macropore domain, which has a pore width in the range of 100 to 700 nm as inferred from their small-angle X-ray (SAXS) and neutron (SANS) scattering behaviour, respectively. Despite the formation of new mesopores or the creation of new networks of pores with rougher surfaces, the fractal behavior of accessible mesopores in combusted shales minimally increase mesopore surface roughness. The pyrolyzed shales exhibit decreased mesopore surface roughness at higher temperatures, which indicates smoothening of pores due to pore blocking. Increase in pore volume and surface area due to oxic-heat treatment enhances the feasibility of long-term CO2 storage in shales.Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Applied Geophysics and Petrophysic