Iraj Sadegh Amiri

Micro-ring resonators (MRRs) are employed to generate signals used for optical communication applications, where they can be integrated in a single system. These structures are ideal candidates for very large-scale integrated (VLSI) photonic circuits, since they provide a wide range of optical signal processing functions while being ultra-compact. Soliton pulses have sufficient stability for preservation of their shape and velocity. Technological progress in fields such as tunable narrow band laser systems, multiple transmission, and MRR systems constitute a base for the development of new transmission techniques. Controlling the speed of a light signal has many potential applications in fiber optic communication and quantum computing. The slow light effect has many important applications and is a key technology for all optical networks such as optical signal processing. Generation of slow light in MRRs is based on the nonlinear optical fibers. Slow light can be generated within the micro-ring devices, which will be able to be used with the mobile telephone. Therefore, the message can be kept encrypted via quantum cryptography. Thus perfect security in a mobile telephone network is plausible. This research study involves both numerical experiments and theoretical work based on MRRs for secured communication.

Nanotechnology has become one of the most important fields in science. Nanoparticles exhibit unique chemical, physical and electronic properties that are different from those of bulk materials, due to their small size and better architecture. Nanoparticles can be used to construct novel sensing devices; in particular electrochemical sensors. Electrochemical detection is highly attractive for the monitoring of glucose, cancer cells, cholesterol and infectious diseases. Unique nanocomposite-based films proposed in this book open new doors to the design and fabrication of high-performance electrochemical sensors.

This book discusses the enhancement of efficiency in currently used solar cells. The authors have characterized different structures of the solar cell system to optimize system parameters, particularly the performance of the Copper-Tin-Sulphide solar cell using Solar Cell Capacitance Simulator (SCAPS). This research can help scientist to overcome the current limitations and build up new designs of the system with higher efficiency and greater functionality. The authors have investigated the corresponding samples from various viewpoints, including structural (crystallinity, composition and surface morphology), optical (UV–vis–near-IR transmittance/re?ectance spectra) and electrical resistivity properties. Describes investigations on Cu2SnS3 solar cells and prospective low cost absorber layer of thin film solar cells;Discusses the potential device structure of Copper-Tin-Sulphide based on thin film technologies;Explains solar cell structure optimization to perform a higher conversion efficiency of Copper-Tin-Sulphide.

This book investigates the effect of sintering temperature on willemite based glass-ceramic doped with different content of Er2O3. It is the first to report research on producing willemite by using waste materials and using trivalent erbium (Er3+) as a dopant. This book provides a survey of the literature on glass and glass-ceramic, while comprehensive experiments and analysis have been performed on the material used.

This book describes Service-Oriented Architecture (SOA) and the significant factors which affect its adoption, such as governance, strategy, complexity, Return on Investment (ROI), business and IT alignment, culture and communication, costs, and security. The study on which this book is based, involved a quantitative analysis to investigate the influential factors for adopting SOA, paving the way to further research in the field.

This book provides detailed and accurate information on the history, structure, operation, benefits and advanced structures of silicon MESFET, along with modeling and analysis of the device. The authors explain the detailed physics that are important in modeling of SOI-MESFETs, and present the derivations of compact model expressions so that users can recognize the physical meaning of the model equations and parameters. The discussion also includes advanced structures for SOI-MESFET for submicron applications.

This book demonstrates the implementation of an automated measuring system for very efficient measurement of chromatic dispersion, which uses a modulation phase shift method over long haul of optical single mode fiber. The authors show how a new scheme for measuring chromatic dispersion is adopted in conjunction with a tunable laser (TLS), providing the optical power at required wavelength and digital oscilloscope (DOSC) for measuring the phase difference between microwave signals from transmitter and microwave signals at the receiver. This is a novel approach for real-time chromatic dispersion in optical systems such as optical fibers. The setup used is very simple, accurate and cost effective, compared to other methods such as direct measurement, differential mode delay, polarization mode dispersion measurement and phase delay method.

This book presents the recent techniques of device fabrication based on optical modulators. The fabrication methods, designed devices, and structural parameters were included in the presented technologies.

This book discusses analytical approaches and modeling of the breakdown voltage (BV) effects on graphene-based transistors. It presents semi-analytical models for lateral electric field, length of velocity saturation region (LVSR), ionization coefficient (a), and breakdown voltage (BV) of single and double-gate graphene nanoribbon field effect transistors (GNRFETs). The application of Gauss’s law at drain and source regions is employed in order to derive surface potential and lateral electric field equations. LVSR is then calculated as a solution of surface potential at saturation condition. The ionization coefficient is modelled and calculated by deriving equations for probability of collisions in ballistic and drift modes based on the lucky drift theory of ionization. The threshold energy of ionization is computed using simulation and an empirical equation is derived semi-analytically. Lastly avalanche breakdown condition is employed to calculate the lateral BV. On the basis of this,simple analytical and semi-analytical models are proposed for the LVSR and BV, which could be used in the design and optimization of semiconductor devices and sensors. The proposed equations are used to examine BV at different channel lengths, supply voltages, oxide thickness, GNR widths, and gate voltages. Simulation results show that the operating voltage of FETs could be as low as 0.25 V in order to prevent breakdown. However, after optimization, it can go as high as 1.5 V. This work is useful for researchers working in the area of graphene nanoribbon-based transistors.

Nanotechnology has become one of the most important fields in science. Nanoparticles exhibit unique chemical, physical and electronic properties that are different from those of bulk materials, due to their small size and better architecture. Nanoparticles can be used to construct novel sensing devices; in particular electrochemical sensors. Electrochemical detection is highly attractive for the monitoring of glucose, cancer cells, cholesterol and infectious diseases. Unique nanocomposite-based films proposed in this book open new doors to the design and fabrication of high-performance electrochemical sensors.

Micro-ring resonators (MRRs) are employed to generate signals used for optical communication applications, where they can be integrated in a single system. These structures are ideal candidates for very large-scale integrated (VLSI) photonic circuits, since they provide a wide range of optical signal processing functions while being ultra-compact. Soliton pulses have sufficient stability for preservation of their shape and velocity. Technological progress in fields such as tunable narrow band laser systems, multiple transmission, and MRR systems constitute a base for the development of new transmission techniques. Controlling the speed of a light signal has many potential applications in fiber optic communication and quantum computing. The slow light effect has many important applications and is a key technology for all optical networks such as optical signal processing. Generation of slow light in MRRs is based on the nonlinear optical fibers. Slow light can be generated within the micro-ring devices, which will be able to be used with the mobile telephone. Therefore, the message can be kept encrypted via quantum cryptography. Thus perfect security in a mobile telephone network is plausible. This research study involves both numerical experiments and theoretical work based on MRRs for secured communication.

Denial of Service (DoS) attacks are a form of attack that seeks to make a network resource unavailable due to overloading the resource or machine with an overwhelming number of packets, thereby crashing or severely slowing the performance of the resource. Distributed Denial of Service (DDoS) is a large scale DoS attack which is distributed in the Internet. Every computer which has access to the Internet can behave as an attacker. Typically bandwidth depletion can be categorized as either a flood or an amplification attack. Flood attacks can be done by generating ICMP packets or UDP packets in which it can utilize stationary or random variable ports. Smurf and Fraggle attacks are used for amplification attacks. DDoS Smurf attacks are an example of an amplification attack where the attacker sends packets to a network amplifier with the return address spoofed to the victim’s IP address. This book presents new research and methodologies along with a proposed algorithm for prevention of DoS attacks that has been written based on cryptographic concepts such as birthday attacks to estimate the rate of attacks generated and passed along the routers. Consequently, attackers would be identified and prohibited from sending spam traffic to the server which can cause DDoS attacks. Due to the prevalence of DoS attacks, there has been a lot of research conducted on how to detect them and prevent them. The authors of this short format title provide their research results on providing an effective solution to DoS attacks, including introduction of the new algorithm that can be implemented in order to deny DoS attacks.

Mobile Ad Hoc Networks (MANETs) are a popular form of network for data transfer due to the fact that they are dynamic, require no fixed infrastructure, and are scalable. However, MANETs are particularly susceptible to several different types of widely perpetrated cyberattack. One of the most common hacks aimed at MANETs is the Black Hole attack, in which a particular node within the network displays itself as having the shortest path for the node whose packets it wants to intercept. Once the packets are drawn to the Black Hole, they are then dropped instead of relayed, and the communication of the MANET is thereby disrupted, without knowledge of the other nodes in the network. Due to the sophistication of the Black Hole attack, there has been a lot of research conducted on how to detect it and prevent it. The authors of this short format title provide their research results on providing an effective solution to Black Hole attacks, including introduction of new MANET routing protocols that can be implemented in order to improve detection accuracy and network parameters such as total dropped packets, end-to-end delay, packet delivery ratio, and routing request overhead.

This book focuses on the analysis and treatment of osteoporotic bone based on drug administration, tracking fatigue behavior and taking into consideration the mechanical interaction of implants with trabecular bone. Weak trabeculae are one of the most important clinical features that need to be addressed in order to prevent hip joint fractures.

This brief analyzes the characteristics of a microring resonator (MRR) to perform communication using ultra-short soliton pulses. The raising of nonlinear refractive indices, coupling coefficients and radius of the single microring resonator leads to decrease in input power and round trips wherein the bifurcation occurs. As a result, bifurcation or chaos behaviors are seen at lower input power of 44 W, where the nonlinear refractive index is n2=3.2×10-20 m2/W. Using a decimal convertor system, these ultra-short signals can be converted into quantum information. Results show that multi solitons with FWHM and FSR of 10 pm and 600 pm can be generated respectively. The multi optical soliton with FWHM and FSR of 325 pm and 880 nm can be incorporated with a time division multiple access (TDMA) system wherein the transportation of quantum information is performed.

This Brief highlights different approaches used to create stable cellulase and its use in different fields. Cellulase is an industrial enzyme with a broad range of significant applications in biofuel production and cellulosic waste management. Cellulase 7a from Trichoderma reesei is the most efficient enzyme in the bio hydrolysis of cellulose. In order to improve its thermal stability, it can be engineered using a variety of approaches, such as hydrophobic interactions, aromatic interactions, hydrogen bonds, ion pairs and disulfide bridge creation.