2016

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    Photovoltaic Water Pumping System Using Maximum Power Point Tracking
    (Department of Electrical and Electronic Engineering, Islamic University of Technology (IUT), Board Bazar, Gazipur-1704, Bangladesh, 2016-11-15) Alam, Muhammad Samiul
    Water resources are essential for satisfying daily human needs varying, from agriculture to energy production. As a tropical country Bangladesh receives a substantial amount of solar insolation suitable for PV application. Being an agricultural economy, the irrigation need is increasing day by day. Use of diesel run pumping system is neither cost effective nor environment friendly. Among the various form of renewable energy technologies Solar photovoltaic technology is perhaps the most used one to generate electricity especially in the rural area of all over the world. The purpose of this research is to analyze the potentiality and cost effectiveness of using solar irrigation system in Bangladesh and also to harness maximum power from the solar panel. The work presented in this thesis present the design and the simulation of a centrifugal pump coupled to a photovoltaic PV generation via a maximum power point tracker MPPT controller. Maximum power point trackers (MPPTs) play a vital role in photovoltaic (PV) systems because they increase the efficiency of the solar photovoltaic system by increasing the power output. The paper presents an Open voltage (OV) scheme for extracting the maximum power from a PV system for use in a water pumping system. A new topology of buck converter is used with feedback PI controller which adjusts the duty cycle of buck converter to match the load impedance to the PV panel, consequently maximizes the motor speed and water discharge rate of the centrifugal pump. The performance of the OV method is evaluated and modeled in SIMULINK environment of MATLAB to confirm the significance of its power improvement and efficient technique for water pumping system.
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    Under water delay tolerant network by accoustic communication and data analysis
    (IUT, EEE, 2016-11-20) Islam, Md Mominul; Haque, Khandaker Foysal; Imtiaz, Salman
    Underwater wireless sensor Network (UWSNs) are finding different application offshore exploration and ocean monitoring. In Most of these applications, the network consists of significant number of sensor nodes deployed at different depths throughout the area of interest. The sensor nodes located at the sea bed cannot communicate directly with the nodes near the surface level. They require multi-hop communication assisted by appropriate routing scheme. However this appropriateness depends not only on network resources and application requirements but also on environmental constraints. All these factors provide a platform where a resource-aware routing strategy plays a vital role to fulfill the different application requirements with dynamic environmental conditions. Realizing the fact, significant attention has been given to construct a reliable scheme, and many routing protocols have been proposed in order to provide an efficient route discovery between the sources and the sink. In this paper, we present a review and comparison of different algorithms, proposed recently in order to fulfill this requirement. The main purpose of this study is to address the issues like data forwarding, deployment and localization in UWSNs under different conditions. Later on, all of these are classified into different groups according to their characteristics and functionalities Delay-tolerant networking (DTN) is a term invented to describe and encompass all types of long-delay, disconnected, disrupted or intermittently-connected networks, where mobility and outages or scheduled contacts may be experienced. ‘DTN’ is also used to refer to the Bundle Protocol, which has been proposed as the one unifying solution for disparate DTN networking scenarios, after originally being designed solely for use in deep space for the ‘Interplanetary Internet.’ We have evaluated the network to be used in underwater data extraction purposes. Underwater terrain is very different from the terrestrial terrain, as it poses more amounts of obstructions where the normal protocols of networking tend to fail. DTN addresses this very problem through the hop-by- hop networking technique to extract data from deep sea and transport the data to the onshore sites for further analysis. This paper has been aimed to provide the best possible solution model that can be designed using DTN to extract data from challenged underwater terrain.
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    A review on supercapacitor & its application
    (IUT, EEE, 2016-11-20) Rahman, Md. Mahbubur; Al Joha, Md. Abdullah; Ahsan, Shadman
    Capacitors are commonly used in electronic resonance circuits; however, capacitors have not been used for storing large amounts of electrical energy in electrical circuits. Also they are not known to be long lasting. Thus appears the need of supercapacitor with variety of electrodes, offering high power density, fast charging & elongated life-cycle. Highly conducting and porous carbon nanotube (CNT) networks are popular as the sole electron conducting material in supercapacitors. The high conductivity of CNT networks and the high surface area allow the replacement of both the metallic current collector and the active material that forms one side of the electrochemical double layer. The combination of both functions in one single layer leads to lightweight charge storage devices that can be manufactured using simple and cheap room temperature methods. In case of solid-state supercapacitor, device fabrication is done by a simple vacuum thermal evaporation method, which allows not only a multilayer stacking structure to further enhance the capacitance, but also permits the supercapacitor to be easily incorporated with other electronic devices, showing interesting characteristics for both fundamental study and practical applications. supercapacitors are being used to increase the efficiency of hybrid electric vehicles in several ways. Aging of a capacitor is a topic to be concerned about. The voltage difference in cells and temperature tend to shorten the life span. Methods are being developed to tackle this problem. Until recently, supercapacitors were relegated to fairly mundane applications such as memory protection and internal battery backup, but in the last few years the application space has broadened significantly into hybrid vehicles, smartphones, and energy harvesting. New technologies on the horizon promise to bring supercapacitors into full competition with rechargeable batteries
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    Prospect of renewable energy based power systems in Africa (Cameroon-Djibouti-Somalia)
    (IUT, EEE, 2016-11-20) Boubakari, Abdoulaye; Tahir, Ali Khalid; Osman, Said
    Cameroon has vast renewable energy resource potentials, with a hydropower potential of about 55,200MW, second only to the Democratic Republic of Congo in Africa. So far, its energy needs are met by 4.8% hydropower (which accounts for less than 5% of its total hydropower potential), 0% wind and 0% solar. Cameroons’ energy sector still goes through insufficient electrical energy production, especially during the heart of the dry season, which runs from December through March. Coincidentally, the wind and solar power potentials for Cameroon are at their peak during these months and could conveniently supplement for the shortfalls in generation during these periods. In this research, technical analysis was carried out to determine the wind and solar energy resource potentials for Cameroon using the Homer Pro software tool provided by CANMET Canada. This analysis revealed that the northern regions of Cameroon had higher wind and solar resource potentials than any other location in Cameroon. A 2MW installed wind energy capacity would be capable of generating well over 1.5GWh electrical energy per year, while a 2KW installed solar energy capacity will be capable of generating well over 3MWh electrical energy per year. In the final sections, financial analysis was carried out to determine the economic viability of such projects and the possibility for self-financing. Emission analyses were also done based on the ability for such projects to offset greenhouse gas emissions and ensure sustainability in the energy sector. The analysis for Maroua revealed that 78.6tCO2/yr. for wind and 0.1tCO2/yr. for solar could be reduced by those installations. Finally, the legislations and legal frameworks governing the energy sector in Cameroon were dissected to determine possible weaknesses and constraints limiting the use, promotion and development of the full potential of Cameroon’s renewable energy resources. From the weather data recorded on the site of Dogba-Maroua over a period of 12 months (April 2015 to April 2016), a design engineering of a wind park of 30 KW in the region of 11 the far-north of Cameroun was carried out. The analytical study of wind parameters (speeds, directions, turbulences intensities) was made with the Homer Pro software. The study undertaken with the wind-generator of the Alstom ECO 100/3000 Class I, having a power of 3000 kW, 100 m diameter of rotor reveals an annual energy production of 22 699,5 MWh / year the directions where the wind blows are more recorded in sectors 30°NNE, 60°NE, 0°N and 90°E and are opposed to the directions where the flow winds are most turbulent (330° NNW, 0° N, 30° NNE, 60°).
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    Optical fiber for terahertz wave
    (IUT, EEE, 2016-11-20) Rahman, Jamilur; Rafi, Md. Abdur; Uddin, Md. Ashfaq
    Terahertz radiation occupies a middle ground between microwaves and infrared light waves known as the terahertz gap, where technology for its generation and manipulation is in its infancy. The frequency band of 0.1-10 THz, known as THz band has brought potential applications in many important fields. For wave propagation THz systems use free space as medium. But in free space waves face many difficulties which is very big issue for wave propagation. So we have to use guided transmission instead of unguided transmission. In the mean time many guided transmission line has many kinds of deprivation such as effective material loss, confinement loss, bending loss, dispersion loss, power fraction issue etc. So we had decided to make a porous core fiber which has less losses than other PCF. Mainly we have been inspired from previous papers in which these losses was too much high for THz wave guidance. Then we have designed rotate hexagonal core and decagonal cladding with 8% PML of total fiber radius. This design gives a lower effective material loss and comparatively higher mode power propagation as well as a flattened dispersion gained over the frequency range 0.95-1.25 THz.
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    Online Live Street watch application supported by LTE-A & Automated Switching to Selected UE Mode of Operation for Restricted Area in LTE
    (IUT, EEE, 2016-11-20) Hasan, Mahmudul; Samad, Mustakimus; Abdussami, Rafiul
    The online applications for street information have gained much popularity and wide use recently. The growing data rate of cellular services at affordable cost is supporting such applications. The Long Term Evolution (LTE) and its later version, LTE-Advanced (LTE-A) are now the most promising technologies for the cellular services. The street information, presently available online for general users, is either limited or not presented in enough user-friendly way. In this paper, we discuss a user-friendly approach for an application that provides online live view of the streets disseminating a lot of information. We analyze the potential usefulness of this application. We consider the use of LTE-A to upload video data from traffic cameras for the application. We propose a method to configure less frequent transmission of cell measurement reports in LTE-A in order to save wireless resources and power during this video data upload.
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    Nuclear Power Need & Key Issues:
    (IUT, EEE, 2016-11-20) Hoque, A.K.M. Ashraful; Mahmud, Rafid Hasan; Noor, Rashed-Uz-Zaman
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    Metal Nanoparticle Induced Enhancement of Light Absorption in Thin-film PV Cells
    (IUT, EEE, 2016-11-20) Ohib, Riyasat; Yeasar, Samin; Ali, Sayem
    The aim of this thesis is to investigate the utilization of plasmonic metal nanostructures for efficiency enhancement of thin-film solar cells. This efficiency enhancement strategy exploits the strong near-field enhancement and highly efficient light scattering that originates from localized surface plasmon resonances (LSPRs) excited in metal nanostructures and leads to an increased absorption in the solar cell active layer. In the first part of this thesis, the near-field enhancement is explained with rigorous theoretical details and how the electromagnetic characteristics alters significantly if a nanoparticle interacts with an incoming field. We have simulated in COMSOL the incoming electric and magnetic field pattern for a single dielectric particle. We have also shown the far-field radiation pattern and scattering characteristics. We have also demonstrated the enhanced resonant electric field (Hot Spot) and wavelength for peak electric field between 2 nanoparticles in close proximity. Later on, we have constructed models where we chose different metal nanoparticles (Al, Cu, Ag, Au) covered by thin-film absorber layer (GaAs, CdTe). We have measured the enhanced magnitude of absorption and scattering in presence of each of these nanoparticles which boosts the efficiency of an otherwise lacking thin-film absorber without the implementation of nanoparticles. Also we have demonstrated how varying the size of the nanoparticles impacted on the absorption enhancement. We have also delved into the recently emerging organic solar cell technology, very particularly, the Perovskite solar cell. Introducing nanoparticles into the Perovskite absorber layer results in higher absorption and scattering. We have measured the absorption enhancement in presence of different noble metal NPs (Al, Cu, Ag, Au). Also we have demonstrated the effect of the radius of the each of the metal NPs into absorption enhancement. Due to this absorption enhancement, the plasmonic nanostructured cell exhibits an enhanced power conversion efficiency compared to an optimized, high performance organic solar cell
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    Low Loss Porous Core Photonic Crystal Fiber for Long Distance THz Radiation
    (IUT, EEE, 2016-11-20) Reza, KM Samaun; Rahman, S.M. Shafi-Ur; Hossain, Riasat Tanjim
    Fiber optic systems are important telecommunication infrastructure for world-wide broadband networks. Wide bandwidth signal transmission with low delay is a key requirement in present day applications. Optical fibers provide enormous and unsurpassed transmission bandwidth with negligible latency, and are now the transmission medium of choice for long distance and high data rate transmission in telecommunication networks. Our main objective is to design an optical waveguide which will be able to transmit terahertz signal into longer distances. In this thesis, two Porous-Core Photonic Crystal Fiber with ultralow Effective Material Loss (EML), high core power fraction and ultra-flattened dispersion is proposed for terahertz (THz) wave propagation. All the simulations are performed with Finite Element Modeling (FEM) package, COMSOL v4.3b. The design can be fabricated using stack and drilling method. This thesis examines effective material loss, core power fraction, modal effective area, dispersion, birefringence, confinement loss of the proposed waveguides. Characteristics analysis is done by varying the geometrical parameters. The results of the analysis are further compared with those of previous reported contributions
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    Graphene Based Luminescence and Optoelectronics
    (IUT, EEE, 2016-11-20) Choudhury, Irfan Ahmed; Al Mamun, Fahad
    Charge carriers in graphene mimic two-dimensional massless Dirac fermions with linear energy dispersion, resulting in unique optical and electronic properties. They exhibit high mobility and strong interaction with electromagnetic radiation over a broad frequency range. Interband transitions in graphene give rise to pronounced optical absorption in the mid-infrared to visible spectral range. Free-carrier intraband transitions, on the other hand, cause low frequency absorption, which varies significantly with charge density and results in strong light extinction at high carrier density. These properties together suggest a rich variety of possible optoelectronic applications for graphene. But graphene is a zero bandgap material which hinders the uses of graphene in luminescent application. In this thesis paper, we have addressed this bandgap problem and reviewed some of the important achievements so far in introducing bandgap in graphene.we have also investigated the optoelectronic properties of graphene and reviewed some of the significant applications.Later, we have discussed about graphene quantum dot and their applications in multicolor light emitting applications and in solar cells