http://20.198.91.3:8080/jspui/handle/123456789/3548 2026-03-12T04:31:29Z 2026-03-12T04:31:29Z Giri, Arindam http://20.198.91.3:8080/jspui/handle/123456789/1027 2025-03-25T10:30:02Z 2022-01-01T00:00:00Z

Title: Development of energy efficient and location-aware approaches for IoT and WSN based framework for precision agriculture Authors: Giri, Arindam Abstract: ABSTRACT Internet of Things (IoT) has become an inevitable part of our life. Wireless sensor network (WSN) can be integrated into IoT to meet the challenges of seamless communication between things. IoT and WSN can be used in precision agriculture where data are collected from crop field and analyzed to take timely decision about farming. In precision agriculture application utilizing IoT and WSN, crop field can be better monitored. Farmers can take many decisions about farming like harvesting and irrigation. Sensors can be deployed in crop field to collect related data like humidity, temperature, nutrients, etc. with the help of IoT. However, sensors have limited energy as they are battery-powered. Their limited energy is dissipated in sensing and sending data to other sensors. A sensor (known as mote) is generally battery powered with initial energy in the order of 1 Joule only. Generally, the battery is not replaced as the sensors are deployed in different environment and not easily reachable always. In smart precision agriculture using IoT and WSN, all operations like routing should be done in energy efficient way due to limited energy of sensors. To know the affected crop area, the sensors must be location-aware in precision agriculture. Again, as the sensors are vulnerable to many attacks like physical or network attacks the localization methods need to be secured in such application. This thesis proposes a framework using IoT and WSN where agricultural processes will be automated. The application requirement for this is real-time monitoring and continuous sensing and transmission. These on the other hand require energy efficient WSN. An energy efficient routing protocol is to be developed for real time monitoring of agricultural field. Sensor nodes are vulnerable to many attacks also. For successful implementation of the framework the underlying WSN must be energy efficient and location-aware. Energy efficiency in data collection is achieved by clustering and routing while security is provided by a secure localization method. Hence, combining location-aware sensor nodes with energy-efficient clustering in WSN will be an effective IoT-based application in precision agriculture.

2022-01-01T00:00:00Z Ojha, Swarupa http://20.198.91.3:8080/jspui/handle/123456789/1026 2025-03-25T10:31:44Z 2021-01-01T00:00:00Z

Title: Study of electrical relaxation of some transition metal ion doped Chalcogenide glass-nanocomposites Authors: Ojha, Swarupa

2021-01-01T00:00:00Z Samanta, Abhishek http://20.198.91.3:8080/jspui/handle/123456789/1022 2025-03-25T10:36:34Z 2021-01-01T00:00:00Z

Title: Experimental investigation & thermodynamic modeling of a diesel engine to analyze performance, energy, emission and exergy using edible and inedible biodiesel blends Authors: Samanta, Abhishek Abstract: Abstract The demand for energy alternatives other than conventional fossil fuel is growing in the modern era as the rise in depleting fossil fuel prices and thriving interest in the environment. Most developing countries are primarily dependent on the supply from the volatile international market that affects their socio-economic growth. Non-renewable resources, such as fossil fuels, can be substituted by renewable resources such as biofuels obtained in liquid (biodiesel) and gaseous form (hydrogen, biogas, producer gas). By adopting new policies, generations of biodiesel have expanded in the modern era in numerous countries. Biodiesel is acknowledged as a 'green fuel' with diverse superiority compared to petroleum diesel. It is non-toxic, renewable, and safe to handle. Also, biodiesel is biodegradable. The low sulfur content with an increased flashpoint compared to petroleum diesel makes the biodiesel a promising suitable automotive fuel in the near future. According to FAO (Food and Agricultural Organization) Italy, the rapid escalation in biodiesel generation is alarming as biodiesel's extensive use would develop greater constrain on food supply, and adverse social and environmental consequences could arise. Though no possible unanimity can be validated, the high food price does not correlate with edible seed oil production. However, more significant investments in the agricultural sector offer probable everlasting convenience for agriculture and rural development. In Malaysia, the palm tree was popularized since 1870 as an exquisite plant. In 2014 the universal production of oil had expanded about 155.8 million tons. Only in Malaysia, there was 60% growth of palm agricultural land by 2005. The fruit of the palm tree is produced two or three years after being planted. Palm trees produce fruit for twenty-five years. The amount of oil produced per hectare is more as compared to other oilseed crops. In 2014, Malaysia's government had mandated the adoption of 5% palm oil methyl ester biodiesel (B5) with petroleum diesel in the transport sector entire nationwide. In 2018 researchers have claimed that industrial palm oil can yield sufficient biodiesel (POME) to balance Malaysia's total diesel consumption effectively. Diesel engine manufacturers provide engine warranties on biodiesel's consumption up to B7 in Malaysia, and the fact that without any significant modification, the diesel engine can handle biodiesel-diesel blends up to B100 (100% biodiesel) can promise a better future environment. Global biodiesel generation is based on edible oil such as Palm, Sunflower, etc. However, in India, Bangladesh, and Pakistan, where scarcity of food is a prime concern, biodiesel production from edible oil is not very welcome. Some inedible oils are accessible in these countries, which are prescribed for biodiesel generation. Azadirachta Indica (neem) thrives in different regions of Asia (India, Bangladesh, etc.) in the genre 'maliaceae'. This herbal and holy tree can grow up to 18 meters with 40% oil content seed. Triglycerides and other triterpenoid composites are found in neem oil with mainly palmitic acid and stearic acid. Waste vegetable oil (WVO) indicates the oil after cooking, which is a waste product and is produced by food industries at the time of food formation. A noticeable hefty amount of WVO is spawned by the hotel, restaurant, and food chain industries and ditched into illicit dumping ground and river. The use of WVO in biodiesel production can cut down the production cost and hazardous waste dump. In the long run, pure biodiesel directly in the engine can cause complications of injector & delivery valve clogging, severe engine deposits, and a sticky piston ring. Inedible vegetable oil biodiesel blend can be applied to compensate for the total consumption of petroleum diesel. Due to high viscosity, flash point, density, and low heating value, raw vegetable oil cannot be straightly used in an unmodified diesel engine. Vegetable oil is required to be transformed into biodiesel to achieve the required properties as engine fuel. The neem oil and waste cooking oil biodiesel from inedible sources can be utilized commercially as a counterfeit for petroleum diesel. Also, the esterifies product maintain tolerable fuel properties according to the American Society for Testing and Materials (ASTM), European Committee for standardization (EN) & Bureau of Indian Standards (BIS). There are a thriving amount of works dedicated to the generation and application of various biofuels. In the modern era, the utmost prevailing substitute to Petroleumbased diesel is biodiesel; chemically, it was known as an alkyl ester of fatty acids from various plant and animal sources. Biodiesel has more oxygen in its structure cause of its organic nature, which allows widespread oxidation of fuel, resulting in complete combustion. Due to biodiesel's more significant cetane number, it has good self-ignition characteristics, which benefits in its combustion and permits achieving comparable thermal efficiency values regarding engine powered by diesel fuel. Biodiesel also reduces the formation of CO, HC, and soot particles in the engine. However, the NOx emission from the engine with biodiesel is found to be higher. IC engines' exergy and energy analysis has been considered for almost decades to estimate the various losses developing during the CI engine operation. The value of useful work is represented by exergy, which a system can provide when moving toward the reference environment by a reversible process. Analysis of exergy can assess the location, type, and magnitude of energy losses in various engine areas. Hence, analysis of exergy provides a context to take necessary action for reducing the losses in different parts of the engine. Numerous research works have been done on CI Engines in various capacities. Most of the works are cited based on the experimental investigation to find out the engine performance. Researchers are recently showing more interest in simulating the engine performance to get optimum engine operating parameters instead of build and test method that requires more time and expense. Commonly simulation of the engine can be done considering the engine cylinder volume as 'single zone,'' multi-zone,' and 'multidimensional'. Generally, single-zone thermodynamic models are used to have a fast and primary analysis of engine combustion and performance. In the single-zone model, it is assumed that the cylinder charge is a uniform or homogeneous mixture with the same temperature and composition for all the time during the engine cycle. The model must be based on empirical heat-release laws to use a single-zone model in diesel engines. A multidimensional model sets the cylinder's space on a fine grid, but it requires detailed information of many phenomena inside the combustion chamber. This kind of approach has its disadvantage in computational time and the need for massive storage space. The multizone model is an intermediate step between single-zone and multidimensional models. Multizone models can be effectively used to model diesel engine combustion systems. However, Multizone models are generally not any good than single-zone models since the phenomena of zone characteristics and interactions inside the combustion chamber are unknown. Single-zone models are one of the simplest and fastest methods to model engine combustion processes. Based on the above discussions, the present work deals with biodiesel production from three different vegetable oil. Biodiesel production from edible palm oil, inedible neem oil, and waste vegetable oil was executed, and biodiesel's characteristics were studied. Palm oil has been established as a suitable biodiesel resource in various countries. Neem oil (considered inedible but herbal tree) is available in India and tropical regions. Waste vegetable oil is a waste product produced by food industries and available in plenty throughout the world. The optimal parameters as catalyst concentration, the molar ratio of methanol and oil, reaction time, and temperature for high biodiesel yield of palm oil biodiesel were determined by the Taguchi method. An experimental investigation to study the combustion, performance, emission characteristics of biodiesel fired C. I. engine were carried out with different biodiesel blends (B5, B10, B15, B20) under various engine load conditions at three different compression ratios. The energy in terms of shaft energy and associated energy loss and exergy as exergetic efficiency were analyzed based on experimental data. Also, the CI engine model was developed in an in-house code using a single zone approach fueled with biodiesel blends. The combustion product model was incorporated in the model. Finally, the CI engine simulation model was validated with the experimental results fueled with biodiesel blends.

2021-01-01T00:00:00Z Syed Mujibur Rahman http://20.198.91.3:8080/jspui/handle/123456789/1016 2025-03-25T10:37:38Z 2021-01-01T00:00:00Z

Title: Assessment of wind energy potential in some locations of north eastern region of India and CFD analysis of vertical axis wind turbine Authors: Syed Mujibur Rahman Abstract: In the application of wind energy conversion technology the kinetic energy of the wind is converted into useful electrical energy. However, as the wind energy is stochastic in nature, the analysis of wind characteristics and assessment of wind energy potential is vitally important for the selection or design of appropriate wind turbine of the concerned site before its installation. Therefore, this thesis is concerned with the assessment of wind power potential of some locations in Northeastern and Eastern regions of India and then CFD analysis of vertical axis wind turbine which can be deployed in such regions to assess the performance of rotors with some new airfoils section. Simultaneously, the present study also includes development of a new proposed estimation method namely, Energy Variance method (EVM) which can be effectively used in the assessment of wind energy potential. For the assessment of wind energy potential four important locations namely, Imphal, Shillong, Guwahati and Kolkata the capital or the business capital of Manipur, Meghalaya, Assam and West Bengal respectively have been selected from the Northeastern and Eastern regions of India. Analysis of the wind characteristics and wind profiles of the all the selected sites reveal that all the sites fall in the low wind speed range and among them Kolkata provides the highest wind power potential followed by Guwahati site while Shillong provides the least wind power potential. Sessional variations show that wind potential is higher during summer and lower during winter for all the sites. Even after extrapolating the data to twice the height of measurement, the available wind power of all the selected sites fall in the low wind power scale and in such situation deployment of vertical axis wind turbine is feasible. Several previous studies showed that two-parameter Weibull distribution model associated with shape and scale parameters is an effective, simple, flexible and best statistical distribution method. However, from the earlier study it is also known that Weibull is properly unable to represent very low speeds in the set of wind speed data to be assessed. Therefore, an alternative model namely, Rayleigh distribution model is employed to assess the available data and the performance of both Weibull and Rayleigh models are compared. The results show that the overall performance of Weibull model is better than the same of the Rayleigh model except in case of Shillong site. It may be concluded that Weibull is still better for the assessment of low to higher wind speed range while Rayleigh model showed better result for the region having extremely low wind speed range. Evaluating the exact and efficient parameters is imperative to get the best fit for the distribution for both Weibull and Rayleigh models. The Weibull parameters are estimated by utilizing four effective methods such as Moment method, Empirical method, Power Density method, and Maximum Likelihood method. Simultaneously, a new approach namely, Energy Variance method is developed which utilizes a non-iterative method to find out the Weibull distribution parameters effectively. Therefore, one of the objectives of the present work is to perform the comparative analysis of the proposed new method with four effective widely accepted estimation methods. The performance shows that the proposed Energy Variance method is a potential which provides the least error in case of Guwahati and Kolkata sites while the maximum likelihood method and moment method show the least error in case of Shillong and Imphal sites respectively. However, the overall performance shows that Energy Variance method is an effective and the most accurate method for estimating Weibull parameters followed by Maximum Likelihood method and Moment method for this region. Therefore, this new method may be considered as an improved, efficient and alternative estimation method for estimating Weibull parameters for wind energy applications. Further, once the assessment of wind potential is completed, the next phase is to find suitable device to tap maximum possible energy from the stated energy source. A wind turbine is a device that can harness useful energy from wind energy source. Although there are two types of wind turbines: Horizontal Axis Wind Turbines and Vertical Axis Wind Turbine, the latter is more suited for the Northeastern and eastern regions as stated above. However, efficiency of vertical axis wind turbine is remarkably less than horizontal axis wind turbine and consequently the most important challenge of the former one is to enhance its aerodynamic performance. Earlier study showed that selection of efficient airfoil shape is an important criterion to enhance overall performance of wind turbine. Therefore, the last objective of the present work is to do two dimensional Computational Fluid Dynamics analysis of three bladed H-type Darrieus wind turbine having blade profile of NACA0019 and NACA0016 which are neither too thick nor too thin and the effectiveness of these profiles for harnessing wind energy are not reported till date. Prior to the Computational Fluid Dynamics simulation two dimensional mesh is generated using Ansys Meshing tool and then sliding mesh technique is used to simulate the rotational motion of the wind turbine. SST k-ω turbulence model is employed for the flow simulation. Initially both mesh and time step are optimized to reach independent solutions. Then the results from the simulation are compared with the pre- existing experimental result for the purpose of validation. xiii For this study several parameters such as lift coefficient, drag coefficient and torque coefficient are considered. The vortical structures at three different input wind speeds are also compared. Finally, the power coefficient curves at different speeds with respect to optimal value of tip speed ratio are compared. It is observed that power coefficient increases as the input wind speed increases. Further, the performance of these two new airfoils are compared with an effective airfoil namely, NACA0015 which has been already accepted for excellent performance in wind turbine applications. The analysis reveals that the power coefficient of NACA0019 airfoils resulting from the CFD simulation is comparatively high and may be considered as one of the effective and alternative airfoil for the Darrieus VAWT which also provides better structural strength than thinner NACA 4 digit series like NACA0018, NACA0016 and NACA0015.

2021-01-01T00:00:00Z