Thesis 2014

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    Study of the Efficiency of Different Types of Solar Cells
    (East West University, 12/18/2014) Afrad, Nusrat Jahan; Sutradhar, Rajib Chandra
    Solar energy, radiant light and heat from the sun, have been harnessed by humans since ancient times using a range of ever-evolving technologies. Solar energy technologies include solar heating, solar photovoltaics, concentrated solar power and solar architecture, which can make considerable contributions to solving some of the most urgent problems the world now faces. The International Energy Agency projected that solar power could provide "a third of the global final energy demand after 2060, while CO2 emissions would be reduced to very low levels." Nowadays the world energy demands around500 exajoule. In 2050, the demand will be around 1000 exajoule. From fossil fuel we may have got almost 85%. Rest of the world demand may be mitigated from alternative energy sources like Solar, Coal, Oil, Natural Gas, Biomass, Geothermal, and even the wind and hydropower. Most of the power generated nowadays is produced using fossil fuels, which emit tons of carbon dioxide and other pollution every second. More importantly, fossil fuel will eventually run out. In order to make the development of our civilization sustainable people are looking for new source of substitute clean energy. Of them solar energy is the potential alternative cause less harm to our environment, carbon emission in the environment is zero, low initial cost, solar systems performance more efficient, economical and stable. Moreover, solar cells are a promising renewable, carbon-free electric energy resource to address the fossil fuel shortage and global warming. In this work,we tried to make a brief review and present status of solar cell conversion efficiency, material usually used for fabrication and different solar cell technology on the most promising routes to realize cheap and efficient solar cells. It is found that the a:Si solar cells have a highest efficiency of approximately 25% in laboratory and 15% in industry, compound semiconductor solar cells have an efficiency of 28.8% (GaAs) and thin film solar cells have an efficiency of 19.6% (CdTe), and HIT solar cells have an efficiency of 22.3%.
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    First Aid-An Android Application
    (East West University, 12/18/2014) Afroz, Selina; Choudhury, Maha
    My task was to design and implement an android application that would enable users to interact as a guide. The dedicated application supports IOS and android all version .The significant part was dedicated for designing and implementing a restful API which constitutes communication protocol between client application and the web service. First Aid application takes advantage of many solutions and techniques for the android platform. It has been optimized according to the practices recommended by Google in order to increase user experience and reduce power consumption. The application is design in such a way that provides medical services to mass people with a platform for instant, Personalized.
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    Diabetics Guide- An Android Application Project
    (East West University, 12/5/2014) Nupur, Nahida Islam
    My task was to design and implement an android application that would enable users to interact as a guide. The dedicated application supports OS version from Ice-cream sandwich 4.0 onwards. The significant part was dedicated for designing and implementing a restful API which constitutes communication protocol between client application and the web service. Diabetics Guide application take advantage of many solutions and techniques for the android platform. It has been optimized according to the practices recommended by Google in order to increase user experience and reduce power consumption. The application is design in such a way that provides mass people awareness of their health.
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    Project Development and Performance Study of a Microcontroller-Based Solar Radiation Measuring System
    (East West University, 12/14/2014) Anzir, Mahmud; Lemon, Md. Majadul Islam
    Measurement of solar radiation is essential for determining the viability of a solar system in a particular place. The conventional measuring system embraces some instruments which are very costly. The target of this project is to develop and study the performance of a microcontroller based solar radiation measuring system with locally available low cost components. In this project, ARDUINO UNO has been used as microcontroller and the source code has been written in arduino software by using arduino C programming. As the sensor of the system a tiny solar cell has been used. The cell converts the solar radiation into current. A current to voltage converter (C-V) has been used to get voltage for the micro controller. The output voltage of the C-V unit is converted into digital value and then displayed in LCD. We have also applied our own logical policy and used some vital instruments to reach the destination of this project. The system has been calibrated using a standard pyranometer. Using the system we have measured the radiation for some days. The entire practical outcomes are presented in this report.
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    Attenuation and Phase Shift Characteristics of Electromagnetic waves in Single Walled Carbon Nanotube
    (East West University, 12/12/2014) Khanruhit, Mohiuddin; Afreen, Farzana
    As one of the most important materials in the Nano area, carbon nanotubes have generated broad and interdisciplinary attention in the last two decades. Carbon Nanotube (CNTs) was discovered by Sumio Iijima[1] in 1991. After the discovery, CNTs have found enormous importance for many applications in the field of nanotechnology, electronics, sensors and optics, due to their unique electrical and mechanical properties, and extremely high aspect ratio. Over the last couple of decades potential efforts have been dedicated to predict and measure the electrical properties (resistance, inductance and capacitance) of CNTs [2-4]. After the first report of FET fabrication using SWCNT (single walled carbon nanotube) [5], it has widely been used to fabricate Diode, MOSFET, and Bipolar devices. Large scale integration using CNTs has been reported by Rao et al [6]. CNTs have been introduced as a new material for potential applications in inter-chip and intra-chip interconnections [7], antenna material for GHz to THz technology [8-10]. With the predicted progress towards nanometer-scale feature sizes, GHz clock rates, and microwave wireless communications, there is a growing need to understand the properties of circuits, interconnects, devices, and antennas with Nano-scale dimensions. Carbon nanotubes offer a combination of small size, high mobility, large current density (about 109 A/cm) [11] and low intrinsic capacitance; moreover, their intrinsic cut-off frequency is expected to be high. Therefore they are among the candidates to eventually candidate for GHz to THz Nano-antennas.
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    Large Mode Area Hexagonal Photonic Crystal Fiber
    (East West University, 12/5/2014) Dilshad-Uz-Zaman; Nur, Mir Md. Tanvir
    In this project we deal with the Photonic crystal fiber. Here we design a model of hexagonal photonic crystal fiber which contains five air hole rings with perfectly matched absorbing layer. We use COMSOLE Multiphysics to design this model. We use finite element method of COMSOL Multiphysics to design proposed hexagonal photonic crystal fiber. Finite element methods for approximating partial differential equations that arise in science and engineering analysis find widespread application. We have changed the value of pitch which means the distance between two air holes. Our target is to design a model which have large mode area, so that we gradually change the pitch up to 18 μm and fixing the diameter on 0.5 μm. From the numerical result it is found that for the higher value of pitch we obtained large mode area.
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    Design and Simulation of Ultra-Thin CdS-CdTe Thin-Film Solar Cell
    (East West University, 12/1/2014) Banik, Sowrabh; Shekh, Md. Shoeb Kabir
    Cadmium telluride (CdTe) has long been recognized as a strong candidate for thin film solar cell applications. It has a band gap of 1.45 eV, which is nearly ideal for photovoltaic energy conversion. Due to its high optical absorption coefficient essentially all incident radiation with energy above its band-gap is absorbed within 1±2 mm from the surface. Thin film CdTe solar cells are typically hetero junctions, with cadmium sulfide (CdS) being the n-type junction partner.Cadmium telluride (CdTe) is the leading material for realization of low cost and high efficiency solar cell for terrestrial use. In this work, the CdTe conventional structure was investigated and achieved the maximum conversion efficiency of 25.16% with CdS. To explore the possibility of ultra-thin and high efficiency CdS-CdTe solar cell, the CdTe absorber layer and CdS window layer were decreased and found that 1 μm thin CdTe layer showed reasonable range of efficiency. Moreover, it was found that there were scopes to increase cell efficiency by reducing the cadmium sulfide (CdS) window layer thickness. The CdS window layer was reduced to 50 nm. All the simulation have been done using Analysis of Microelectronic and Photonic Structures (AMPS 1D) simulator. The maximum conversion efficiency of 25.16% (Voc= -1.078 V, Jsc= 26.330 mA/cm2, FF = -0.887) was achieved with 1 μm- CdTe absorber layer, 50 nm-CdS window layer.
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    IP Telephony System Company: KrisEnergy Bangladesh Ltd. Department: IT
    (East West University, 9/7/2014) Shoma, Ishrat Nowrin
    This report describes about my experiences during my internship period in KrisEnergy Bangladesh Ltd. In this report I have tried to brief about the corporate life for the beginners as well as my work experience on IP telephony system. I tried to give a detail on what I have done and how I have learned about the practical application of IP phone from my colleagues. here is information of some related equipments with IP Phone such as switch, router etc. As my main work responsibility was to configure those devices I tried to give in details that how I configure those devices. I have also included the ideas about IP Phone System and its related problems and maintenance. This report will help to understand about the corporate life and brief about the devices based on my knowledge that I gathered during the last three months of my internship· period. Here I also shared my personal experience on the organization. The report is ended with concluding part with the references.
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    Digital Signature Certificate of Dataedgeid of Data Edge Ltd
    (East West University, 9/11/2014) Arman, Arif
    This intern report represents the concepts of Digital signature Certificate along with SSL and Public Key Infrastructure and their implementation in Bangladesh. Public Key Infrastructure provides a model of secured network of communication where an individual or a organization can transmit and receive data securely and Digital signature Certificate is the key by which an individual or organization can get the access to the network for secure transmission of data. Moreover it contains a idea of the Public Key Infrastructure in Bangladesh published by Office of the Controller of Certifying Authority (CCA) under ICT Division of Bangladesh government and Certificate Practice Statement of data edge ltd. To do analysis with practical work, some related theories are discussed in this intern report.
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    Shanta Properties- An Android Application & Pride and Prejudice- An EBook Application
    (East West University, 8/24/2014) Ahmed, Anik; Hossain, Shaikh Rayhan
    The concept "mobile applications" has become very central lately and has indeed turned into a great impact on our everyday life. The fact that almost every mobile Phone is capable of much more than only making a phone call is one of the reasons that mobile applications have become both more interesting and common. This bachelor thesis has the purpose to investigate OS version from Ice-cream sandwich 4.0 onwards. More in detail the project goal is to examine opens up for new possibilities for the developer to create applications responding to the concept "the next generation of mobile applications". A general presentation and discussion about the concept "android mobile applications" is included in the paper and also a practical part where such an application is implemented. This practical part describes both how programming is done and how programming is done on android applications in general. The application is a real life project which is released on the App Store after the project is done. The application is design in such a way that provides mass people with a platform for instant and a possible future for mobile applications is discussed during the paper.