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Articles 1 - 25 of 25
Full-Text Articles in Engineering
Power Management Of Remote Microgrids Considering Battery Lifetime, Santosh Chalise
Power Management Of Remote Microgrids Considering Battery Lifetime, Santosh Chalise
Electronic Theses and Dissertations
Currently, 20% (1.3 billion) of the world’s population still lacks access to electricity and many live in remote areas where connection to the grid is not economical or practical. Remote microgrids could be the solution to the problem because they are designed to provide power for small communities within clearly defined electrical boundaries. Reducing the cost of electricity for remote microgrids can help to increase access to electricity for populations in remote areas and developing countries. The integration of renewable energy and batteries in diesel based microgrids has shown to be effective in reducing fuel consumption. However, the operational cost …
Frequency Control Of Wind And Pv Based Isolated Microgrid, Lekhnath Kafle
Frequency Control Of Wind And Pv Based Isolated Microgrid, Lekhnath Kafle
Electronic Theses and Dissertations
The wind and solar PV based isolated microgrid can be economical and reliable for the remote area where the grid is not available. The frequency and voltage fluctuation are major problems in such remote microgrid due to intermittent nature of renewable resources like wind and solar PV. The frequency fluctuation should remain within acceptable limits for stable operation of the remote microgrid. This thesis work focuses on frequency control of wind and photovoltaic (PV) based isolated micro-grid using traditional droop control technique. The battery system acts as a master unit which is responsible for setting up the common AC bus …
Sickle Blood Cell Detection Based On Image Segmentation, Kholoud Alotaibi
Sickle Blood Cell Detection Based On Image Segmentation, Kholoud Alotaibi
Electronic Theses and Dissertations
Red blood cells have a vital role in human health. Red blood cells have a circular shape and a concave surface and exchange the gasses between the inside and outside of the body. However, at times, these normally round cells become sickle shaped, which is an indication of sickle cell disease. This paper introduces a unique approach to detect sickle blood cells in blood samples using image segmentation and shape detection. This method is based on calculating the max axis and min axis of the cell. The form factor is computed using these properties to determine whether the cell is …
Product Authentication Using Hash Chains And Printed Qr Codes, Harshith R. Keni
Product Authentication Using Hash Chains And Printed Qr Codes, Harshith R. Keni
Electronic Theses and Dissertations
This thesis explores the usage of simple printed tags for authenticating products. Printed tags are a cheap alternative to RFID and other tag based systems and do not require specialized equipment. Due to the simplistic nature of such printed codes, many security issues like tag impersonation, server impersonation, reader impersonation, replay attacks and denial of service present in RFID based solutions need to be handled differently. An algorithm that utilizes hash chains to secure such simple tags while still keeping cost low is discussed. The security characteristics of this scheme as well as other product authentication schemes that use RFID …
Spatial-Temporal Stochasticity Of Electric Vehicles In Integrated Traffic And Power System, Sadhana Shrestha
Spatial-Temporal Stochasticity Of Electric Vehicles In Integrated Traffic And Power System, Sadhana Shrestha
Electronic Theses and Dissertations
A penetration of a large number of electric vehicles for charging their batteries in the grid can have a negative impact to the grid. To prevent a negative effect to the grid, the behavior of electric vehicles must be accurately modeled and their charging schedules must be coordinated. Therefore, it is necessary to determine where and how much charge is available in electric vehicles in the distribution system. In this thesis, a state transition algorithm is designed to determine a stochastic model of electric vehicles to simulate electric vehicle movement in an integrated traffic and power network. Dijkstra’s algorithm is …
Feasibility Study Of Energy Storage Technologies For Remote Microgrid’S Energy Management System, Md Habib Ullah
Feasibility Study Of Energy Storage Technologies For Remote Microgrid’S Energy Management System, Md Habib Ullah
Electronic Theses and Dissertations
Energy storage systems (ESSs) play a significant role in remote microgrids energy management system (EMS) with the large penetration rate of renewable energy which is intermittent in nature. Energy storage improves system reliability and efficiency in remote microgrids by optimizing the power demand and generation to reduce operational costs. Moreover, it increases the dispatch ability of the energy sources in remote microgrid systems. Lead acid battery (PbA) can be used as an energy storage device in remote microgrids due to its low cost; however, the response rate, short life cycle, and depth of discharge (DoD) lead to high operational costs. …
Plasma Treatment Of Zinc Oxide Thin Film And Temperature Sensing Using The Zinc Oxide Thin Film, Al-Ahsan Talukder
Plasma Treatment Of Zinc Oxide Thin Film And Temperature Sensing Using The Zinc Oxide Thin Film, Al-Ahsan Talukder
Electronic Theses and Dissertations
Zinc oxide is a direct and wide bandgap, II-VI semiconductor. It has large exciton binding energy, large piezoelectric constant, strong luminescence, and high thermal conductivity. These properties make zinc oxide as a suitable material for various optoelectronic applications. Vacuum based processes of fabrication of zinc oxide thin film dominate the market for their better electrical and optical properties. In this work, zinc oxide thin films were prepared by easy and low cost solution method with oriented crystal growth along (002) plane. To improve electrical and optical property of the fabricated zinc oxide thin films, films were treated with oxygen, hydrogen, …
Economic Analysis Of A Data Center Virtual Power Plant Participating In Demand Response, Labi Bajracharya
Economic Analysis Of A Data Center Virtual Power Plant Participating In Demand Response, Labi Bajracharya
Electronic Theses and Dissertations
Data centers consume a significant amount of energy from the grid, and the number of data centers are increasing at a high rate. As the amount of demand on the transmission system increases, network congestion reduces the economic efficiency of the grid and begins to risk failure. Data centers have underutilized energy resources, such as backup generators and battery storage, which can be used for demand response (DR) to benefit both the electric power system and the data center. Therefore, data center energy resources, including renewable energy, are aggregated and controlled using an energy management system (EMS) to operate as …
Composite Gel Polymer Electrolyte For Lithium Ion Batteries, Roya Naderi
Composite Gel Polymer Electrolyte For Lithium Ion Batteries, Roya Naderi
Electronic Theses and Dissertations
Batteries have been ubiquitously utilized in enormous applications such as portable electronics, satellites, computers, medical instruments, and electric cars. The development of battery technology has been through a long journey since the 17th century, paving its way to commercialization of lithium ion batteries in 1991 by Sony. Rechargeable lithium ion batteries represent the most favorable type of batteries for portable applications due to their high energy density compared to other alkali metals. In 1997, lithium polymer batteries with solid polymer/composite electrolyte were introduced where the safety drawbacks of the liquid electrolyte were eliminated but the ionic conductivity of the batteries …
Fully Solution Processed Pedot:Pss And Silver Nanowire Semi-Transparent Electrodes For Thin Film Solar Cells, Bjorn Vaagensmith
Fully Solution Processed Pedot:Pss And Silver Nanowire Semi-Transparent Electrodes For Thin Film Solar Cells, Bjorn Vaagensmith
Electronic Theses and Dissertations
Building integrated photovoltaics (BIPV), such as semitransparent organic solar cells (OSC) for power generating windows, is a promising method for implementing renewable energy under the looming threat of depleting fossil fuels. OSC require a solution processed transparent electrode to be cost effective; but typically employ a nonsolution processed indium tin oxide (ITO) transparent electrode. PEDOT:PSS and silver nanowire transparent electrodes have emerged as a promising alternative to ITO and are solution processed compatible. However, PEDOT:PSS requires a strong acid treatment, which is incompatible with high throughput solution processed fabrication techniques. Silver nanowires suffer from a short lifetime when subject to …
Reflectance-Based Calibration And Validation Of The Landsat Satellite Archive, Sandeep Kumar Chittimalli
Reflectance-Based Calibration And Validation Of The Landsat Satellite Archive, Sandeep Kumar Chittimalli
Electronic Theses and Dissertations
The primary objective of this project was to consistently calibrate the entire Landsat series to a common reflectance scale by performing cross-calibration corrections from Landsat-8 OLI to Landsat- 1 MSS. A consistent radiance-based calibration was already performed from Landsat-8 OLI through Landsat-1 MSS using bright targets and dark targets. The MSS radiance-based calibration results showed an uncertainty of about ±5%. Typically to convert from radiance to reflectance a solar model is used. Unfortunately, there are numerous solar models, all with various levels of accuracies. It was also seen that there is a data format inconsistency for different types of MSS …
Nanoscale Study Of Perovskite Solar Cells For Efficient Charge Transport, Nirmal Adhikari
Nanoscale Study Of Perovskite Solar Cells For Efficient Charge Transport, Nirmal Adhikari
Electronic Theses and Dissertations
The effect of temperature, humidity and water on the grain boundary potential and charge transport within the grains of pervoskite films prepared by sequential deposition technique. Grain boundary potential of perovskite films exhibited variation in electrical properties with humidity level, temperature and water concentration in methyl ammonium iodide solution. X-ray diffraction (XRD) indicates the formation of PbI2 phase in perovskite film with increasing temperature, humidity and adding larger quantity of water in methyl ammonium iodide solution. It is found that optimum amount of lead iodide helps for the passivation of perovskite film. Spatial mapping of surface potential in the …
Cascading Failures And Contingency Analysis For Smart Grid Security, Shiva Poudel
Cascading Failures And Contingency Analysis For Smart Grid Security, Shiva Poudel
Electronic Theses and Dissertations
The modern electric power grid has become highly integrated in order to increase the reliability of power transmission from the generating units to end consumers. In addition, today’s power system are facing a rising appeal for the upgrade to a highly intelligent generation of electricity networks commonly known as Smart Grid. However, the growing integration of power system with communication network also brings increasing challenges to the security of modern power grid from both physical and cyber space. Malicious attackers can take advantage of the increased access to the monitoring and control of the system and exploit some of the …
Efficiency And Reliability Analysis Of Ac And 380v Dc Data Centers, Bijen Raj Shrestha
Efficiency And Reliability Analysis Of Ac And 380v Dc Data Centers, Bijen Raj Shrestha
Electronic Theses and Dissertations
The rapid growth of the Internet has resulted in colossal increase in the number of data centers. A data center consume a tremendous amount of electricity resulting in high operation cost. Even a slight improvement in the power distribution system of a data center could save millions of dollars in electricity bills. Benchmarks for both AC and 380V DC data centers are developed and efficiency analyses thereof have been performed for an entire year. The efficiency of the power distribution system can be increased if number of power conversion stages can be reduced and more efficient converters are used. Use …
Study Of Moisture And Water Effects In Low Temperature Crystallization Of Perovskite Film For Efficient Solar Cells, Ashish Dubey
Study Of Moisture And Water Effects In Low Temperature Crystallization Of Perovskite Film For Efficient Solar Cells, Ashish Dubey
Electronic Theses and Dissertations
Organic-inorganic perovskite solar cells have become a promising alternative to fossil fuel based energy sources due to their unique properties such as tunable low bandgap, long charge diffusion length, low exciton binding energy and balanced charge transport. The semiconducting perovskite films are typically prepared from low temperature solution processing and the corresponding solar cells have exhibited power conversion efficiency (PCE) of more than 20%. However, perovskite solar cells suffer from poor stability in presence of moisture and use of toxic element (Pb). Understanding the crystallization process and the effects of moisture and water is important to obtain high quality perovskite …
Implementation Of Solar Irradiance Forecasting Using Markov Switching Model And Energy Management System, Ayush Shakya
Implementation Of Solar Irradiance Forecasting Using Markov Switching Model And Energy Management System, Ayush Shakya
Electronic Theses and Dissertations
Photovoltaic (PV) systems integration is increasingly being used to reduce fuel consumption in diesel-based remote microgrids. However, uncertainty and low correlation of PV power availability with load reduce the benefits of PV integration. These challenges can be handled by introducing reserve, which however leads to increased operational cost. Solar irradiance forecasting helps to reduce reserve requirement, thereby improving the utilization of PV energy. In this thesis, a new solar irradiance forecasting method for remote microgrids based on the Markov Switching Model (MSM) is presented. This method uses locally available data to predict one-day-ahead solar irradiance for scheduling energy resources in …
The Impact Of Different Battery Technologies For Remote Microgrids, Ali Barjs Allruwaili
The Impact Of Different Battery Technologies For Remote Microgrids, Ali Barjs Allruwaili
Electronic Theses and Dissertations
Energy storage systems are considered an effective solution for remote microgrids. They allow to increase the overall system reliability, performance, and reduce operational cost by increasing the energy utilization of renewable energy resources (PV and wind energy). A battery can reduce the system's operational cost by matching a diesel generator with the load demand. There are many types of batteries which can be used in remote microgrids, such as Lead-acid, Lithium-ion, Zinc-bromine and Aqueous Hybrid Ion. By selecting a battery which provides low operational cost and longer battery life is complex, relying on many key technical features which affect the …
Lead Free Ch3nh3sni3 Perovskite Thin-Film With P-Type Semiconducting Nature And Metal-Like Conductivity, Anastasiia Iefanova
Lead Free Ch3nh3sni3 Perovskite Thin-Film With P-Type Semiconducting Nature And Metal-Like Conductivity, Anastasiia Iefanova
Electronic Theses and Dissertations
CH3NH3SnI3 and CH3NH3PbI3 have become very promising light absorbing materials for photovoltaic devices over the last several years. CH3NH3PbI3 based perovskite solar cells have reached a solar-to-electricity conversion efficiency of ~ 22%. Nevertheless, CH3NH3PbI3 perovskite solar cells contain lead, which has serious consequences for the environment and human health. In this work, the lead was replaced with less toxic tin. Lead free CH3NH3SnI3 perovskite thin film was prepared by two low temperature solution processing methods and characterized using various tools such as Xray Diffraction (XRD) and absorption spectroscopy (UV-VIS). The distinctive p-type semiconducting nature and metal like conductivity of CH3NH3SnI3 …
Urea Pre-Treatment Of N2-Annealed Transition Metal Oxides For Low Cost And Efficient Counter Electrodes In Dye-Sensitized Solar Cell, Hytham Elbohy
Urea Pre-Treatment Of N2-Annealed Transition Metal Oxides For Low Cost And Efficient Counter Electrodes In Dye-Sensitized Solar Cell, Hytham Elbohy
Electronic Theses and Dissertations
Photovoltaic cells have shown great promise as an alternative to fossil fuel-based energy sources. Dye-sensitized solar cells (DSSCs) have shown potential as low-cost replacement to silicon solar cells owing to their reduced material costs and simple fabrication techniques. Platinum (Pt) was used as a catalyst in the counter electrode for DSSCs. Metal oxides have been used as an alternative material to Pt. The introduction of oxygen vacancies inside metal oxides helps to facilitate electron transport to the electrolyte to enhance the reduction process of triiodide ions. Annealing n-type metal oxides under a reducing agent gas such as hydrogen (H2) at …
Breast Cancer Classification Of Mammographic Masses Using Circularity Max Metric, A New Method, Tae Keun Heo
Breast Cancer Classification Of Mammographic Masses Using Circularity Max Metric, A New Method, Tae Keun Heo
Electronic Theses and Dissertations
Breast cancer classification can be divided into two categories. The first category is a benign tumor, and the other is a malignant tumor. The main purpose of breast cancer classification is to classify abnormalities into benign or malignant classes and thus help physicians with further analysis by minimizing potential errors that can be made by fatigued or inexperienced physicians. This paper proposes a new shape metric based on the area ratio of a circle to classify mammographic images into benign and malignant class. Support Vector Machine is used as a machine learning tool for training and classification purposes. The improved …
Virtual Inertia Emulation To Improve Dynamic Frequency Stability Of Low Inertia Microgrids, Dipesh Shrestha
Virtual Inertia Emulation To Improve Dynamic Frequency Stability Of Low Inertia Microgrids, Dipesh Shrestha
Electronic Theses and Dissertations
Due to low inertia and the intermittent nature of photovoltaic systems, dynamic frequency stability issues arise in microgrids with large photovoltaic systems. This limits the maximum amount of photovoltaic systems that can be penetrated in the microgrid. In order to increase the penetration of photovoltaic systems, the dynamic frequency controller, that is faster than the primary frequency controller (governor control) needs to be added in the microgrid system. For dynamic frequency control, inertial response can be provided from the energy storage system (such as battery, ultra-capacitor, photovoltaic system, etc.), which is termed as virtual inertia. A virtual inertia can be …
Game Theoretical Approach For Joint Relay Selection And Resource Allocation In Mobile Device Networks, Runan Yao
Electronic Theses and Dissertations
With the improvement of hardware, more and more multimedia applications are allowed to run in the mobile device. However, due to the limited radio bandwidth, wireless network performance becomes a critical issue. Common mobile solutions are based on the centralized structure, which require an access point to handle all the communication requirement in the work area. The transmission performance of centralized framework relies on the density of access points. But increasing the number of access points will cost lot of money and the interference between access point will reduce the transmission quality. Thanks to the wireless sensor network implementations, the …
Data Center Load Forecast Using Dependent Mixture Model, Md Riaz Ahmed Khan
Data Center Load Forecast Using Dependent Mixture Model, Md Riaz Ahmed Khan
Electronic Theses and Dissertations
The dependency on cloud computing is increasing day by day. With the boom of data centers, the cost is also increasing, which forces industries to come up with techniques and methodologies to reduce the data center energy use. Load forecasting plays a vital role in both efficient scheduling and operating a data center as a virtual power plant. In this thesis work a stochastic method, based on dependent mixtures is developed to model the data center load and is used for day-ahead forecast. The method is validated using three data sets from National Renewable Energy Laboratory (NREL) and one other …
Integrated Tandem Dye Sensitized Solar Cell (Dssc)-Lithium Ion Battery, Geetha Varnekar
Integrated Tandem Dye Sensitized Solar Cell (Dssc)-Lithium Ion Battery, Geetha Varnekar
Electronic Theses and Dissertations
Efficient renewable energy harvesting and storage are needed for present challenges related to clean environment and increasing energy demand. Different types of energy harvesting technologies such as solar, thermal and wind require excess energy to be stored in batteries, which further adds to the complication and increase in cost to the overall renewable energy system. Integrating the generation and storage of solar energy in a single device would be a more cost effective way towards meeting the increasing energy demand due to its simplicity in design and less space consumptions. Herein, a sustainable photovoltaic cell integrated with an energy storage …
Bidirectional Distribution Reflection Function Of Algodones Dunes, Mahesh Shrestha
Bidirectional Distribution Reflection Function Of Algodones Dunes, Mahesh Shrestha
Electronic Theses and Dissertations
The primary objective of this project was to develop the Algodones Dunes as a pseudo-invariant calibration site (PICS) suitable for absolute calibration of satellite sensors based on a surface reflectance model. Two approaches were taken during this research: a field campaign and laboratory measurements. The first approach, the field campaign, was accomplished with a trip to the Algodones Dunes from the 8th to the 13th of March, 2015. During the field campaign, several test points from spatially different regions of the Algodones Dunes were studied. Reflectance of the sand at each test point was observed from different view angles. The …