Performance And Degradation Evaluation Of Grid-Connected Photovoltaic Systems At UTeM

Four grid-connected solar Photovoltaic (PV) systems were installed at Universiti Teknikal Malaysia Melaka (UTeM), namely Thin-Film (TF), Heterojunction with intrinsic thin layer (HIT), Poly crystalline, and Mono crystalline with the total capacity of 24 kWp since October 2013. Hence, it is important to evaluate the performance and the degradation of UTeM’s PV systems. In this regard, this research aims to evaluate the performance and the degradation of three of the four grid- connected PV systems located at UTeM, Melaka. The analysis presented in this study consists of the data recorded at 5 – minute intervals between January 2014 and December 2015. Meteorological parameters such as solar radiation and ambient temperature, module temperature, and solar generation were obtained from research laboratory of solar PV systems, smart grids, UTeM. The annual performance of the PV systems had been evaluated in terms of capacity factor, availability factor, reference yield, array yield, final yield, performance ratio, system losses, and array capture losses. The annual degradation rates of the PV systems were calculated using Power-Irradiance (P-G) technique. The average performance ratio of Thin-Film PV system for 2014 was 93.6% and 89.2% in 2015, while the average performance ratio of HIT PV system in 2014 was 85% and 82.3% in 2015, and the average performance ratio of Mono crystalline PV system in 2014 was 81.3% and 78.7% in 2015. The average degradation rates for two years of operation of Thin-Film, HIT, and Mono crystalline PV systems were 5.32%, 5.1%, and 3.65%, respectively. This study provides the insight for the system installer and investor in relation to the performance and degradation of various types of PV module technologies installed under Malaysia environment

Novel Internet of Vehicles Approaches for Smart Cities

Smart cities are the domain where many electronic devices and sensors transmit data via the Internet of Vehicles concept. The purpose of deploying many sensors in cities is to provide an intelligent environment and a good quality of life. However, different challenges still appear in smart cities such as vehicular traffic congestion, air pollution, and wireless channel communication aspects. Therefore, in order to address these challenges, this thesis develops approaches for vehicular routing, wireless channel congestion alleviation, and traffic estimation. A new traffic congestion avoidance approach has been developed in this thesis based on the simulated annealing and TOPSIS cost function. This approach utilizes data such as the traffic average travel speed from the Internet of Vehicles. Simulation results show that the developed approach improves the traffic performance for the Sheffield the scenario in the presence of congestion by an overall average of 19.22% in terms of travel time, fuel consumption and CO2 emissions as compared to other algorithms. In contrast, transmitting a large amount of data among the sensors leads to a wireless channel congestion problem. This affects the accuracy of transmitted information due to the packets loss and delays time. This thesis proposes two approaches based on a non-cooperative game theory to alleviate the channel congestion problem. Therefore, the congestion control problem is formulated as a non-cooperative game. A proof of the existence of a unique Nash equilibrium is given. The performance of the proposed approaches is evaluated on the highway and urban testing scenarios. This thesis also addresses the problem of missing data when sensors are not available or when the Internet of Vehicles connection fails to provide measurements in smart cities. Two approaches based on l1 norm minimization and a relevance vector machine type optimization are proposed. The performance of the developed approaches has been tested involving simulated and real data scenarios

SIMULATION AND ANALYSIS OF VEHICULAR AD-HOC NETWORKS IN URBAN AND RURAL AREAS

According to the American National Highway Traffic Safety Administration, in 2010, there were an estimated 5,419,000 police-reported traffic crashes, in which 32,885 people were killed and 2,239,000 people were injured in the US alone. Vehicular Ad-Hoc Network (VANET) is an emerging technology which promises to decrease car accidents by providing several safety related services such as blind spot, forward collision and sudden braking ahead warnings. Unfortunately, research of VANET is hindered by the extremely high cost and complexity of field testing. Hence it becomes important to simulate VANET protocols and applications thoroughly before attempting to implement them. This thesis studies the feasibility of common mobility and wireless channel models in VANET simulation and provides a general overview of the currently available VANET simulators and their features. Six different simulation scenarios are performed to evaluate the performance of AODV, DSDV, DSR and OLSR Ad-Hoc routing protocols with UDP and TCP packets. Simulation results indicate that reactive protocols are more robust and suitable for the highly dynamic VANET networks. Furthermore, TCP is found to be more suitable for VANET safety applications due to the high delay and packet drop of UDP packets.fi=Opinnäytetyö kokotekstinä PDF-muodossa.|en=Thesis fulltext in PDF format.|sv=Lärdomsprov tillgängligt som fulltext i PDF-format

Adsorption of Cd(II) and Pb(II) Ions from Aqueous Solution byActivated Carbon

Heavy metal consider as major environmental pollutants. Many of industrial wastewater effluents contain a wide range of these heavy metals. The adsorption of Cd2+ and Pb2+ metal ions from aqueous solution by activated carbon was studied. The results showed that maximum adsorption capacity occurred at 486.9×10-3 mg/kg for Pb2+ ion and 548.8×10-3 mg/kg for Cd2+ ion. The adsorption in a mixture of the metal ions had a balancing effect on the adsorption capacity of the activated carbon. The adsorption capacity of each metal ion was affected by the presence of other metal ions rather than its presence individually. The study showed the presence of other heavy metals attribute to the reduction in the activated carbon capacity, and the adsorption process was found to obeys the Freundlich isotherm for both ions

All-Optical Generation Of Multiwavelength Brillouinerbium Fiber Laser In Long-Wavelength Band

In this dissertation, the design and development of the multiwavelength Brillouin- Erbium fiber laser (BEFL) sources operating in the L-band transmission window is presented and characterized. Four different laser designs have been successfully demonstrated using a combination of stimulated Brillouin scattering effect in optical fiber and Erbium-doped fiber (EDF) amplification. The experimental results obtained from the characterization and optimization of these laser structures are the threshold power, number of the Stokes signals generated, Stokes signals power, self-lasing oscillation and the tuning range. The results are taken from the studies which have been carried out to analyze the effects of 1480 nm pump power, Brillouin pump (BP) power, BP wavelength and single mode fiber (SMF) length. The first laser structure is an efficient multiwavelength L-band BEFL pumped by a 1480 nm pump laser in a linear cavity configuration with direct BP injection into SMF. The issue of low gain efficiency of the L-band in the EDF lasers is resolved with the efficient linear cavity structure and the 1480 nm pumping scheme. The proposed laser structure exhibits a low threshold power of 18 mW and a maximum number of 26 stable output channels with 0.089 nm (10.5 GHz) channels spacing. The second and third laser structures are focused on the enhanced multiwavelength BEFL, in which the BP power is pre-amplified before entering the SMF within the laser cavity. The BP pre-amplification techniques - single pass and double pass represent a new mode of operation of multiwavelength BEFL’s. This intra-cavity BP pre-amplification provided by the EDF has created higher intensity of Brillouin Stokes signals generated in the single-mode fiber that leads to the homogenous gain saturation. This effect is able to suppress the built-up of the self-lasing cavity modes in a wider wavelength range and the number of output channels is also enhanced as compared to the conventional BP direct injection. Output of more than 33 laser channels is achieved and the tuning range is almost doubled than that of the conventional BP direct injection technique. Finally, for the fourth laser configuration, the multiwavelength BEFL incorporates either the amplified fiber loop mirror (AFLM) or non-linear amplified fiber loop mirror filter (AFLMF). Fifty-four stable output channels, with 0.089 nm channels spacing, have been achieved. A non-linear AFLMF which induces wavelengthdependent cavity loss and serves as an amplitude equalizer is employed to shift and flatten the EDF gain spectrum. Two control mechanisms have been demonstrated to shift and flatten the EDF gain profile through the adjustment of the polarization controller in the AFLMF. Therefore, the multiwavelength BEFL could be tuned over the whole L-band window from 1570 nm to 1610 nm with the average number of 24 output channels. In addition, flattening the EDF laser oscillation overcomes the requirements of the BP wavelength tuning, in conjunction with the adjustment of the polarization controllers in the fiber loop

Design and Development of a Novel Multi wavelength Brillouin-Erbium Fiber Laser

Multi-wavelength laser sources with constant wavelength spacing are of great interest in dense wavelength division multiplexing (DWDM) communication and sensors systems.As the transmission capacity of optical communication systems is approaching a few Tb/s through WDM method in recent years, multiwavelength generation technology becomes more important, considering that the complexity and the cost of the source will increase as the number of WDM channel increases.In this thesis, the design and development of a novel architecture of multi-wavelength Brillouin/Erbium fiber laser (BEFL) utilizing a linear cavity fiber loop technique is presented. Simultaneous and stable multiple wavelength lasing in a linear cavity have been achieved. The results are based completely on the experimental work. The requirement of internal feedback that is commonly used for multiple wavelengths Brillouin/Erbium fiber laser using a ring configuration is achieved by the proposed linear cavity design. This design used only a single 980 nm pump laser for its multiple wavelengths operation. Based on the design parameters namely; 980 nm pump power, Brillouin pump power, Brillouin pump wavelength and single mode fiber (SMF) the performance of a novel BEFL is presented in terms of threshold power, Stokes signal peak power, number of Stokes generated, stability of the Stokes and tuning range. Throughout this work, three lengths of SMF-fiber are used, 1.9 km, 8.8 km and 25 km.The optimization of Brillouin pump wavelength, power and Erbium gain led to a maximum possible number of Stokes. Twenty-two stable output laser lines with 10.88 GHz (0.088 nm) line spacing were obtained at 1558 nm that was the peak of Erbiumdoped fiber (EDF) gain. The injected Brillouin pump power into the 8.8 km SMF-fiber was set at 0.9 dBm and the EDF was pumped by 100 mW of 980 nm pump laser.The most efficient cascaded Brillouin Stokes operation occurred at the peak of Erbium gain centered on 1558 nm. The number of Stokes decreased as the Brillouin pump increased in the highest region of Erbium gain. On the contrary, the number of Stokes was proportional to the intensity of the Brillouin pump power outside this wavelength range. The best performance and conversion efficiency of Brillouin pump to the BEFL signal occurs at the lower levels of injected Brillouin pump power.A low threshold of 4 mW pump power with 2.3 mW launched Brillouin pump into the 8.8 km of SMF-fiber at 1558 nm was obtained. The tuning range of the Stokes signal must be taken into account both the Brillouin and EDF pump powers, at a fixed EDF pump power the Stokes signal can be tuned wider at a higher Brillouin pump power while higher EDF pump power produces smaller tuning range

Modelling dynamics of victims' stress during natural disaster

Natural disaster is one of the inescapable phenomenon through which numerous number of individuals are being affected via developing psychological problems. Stress is one of the essential psychological effects of natural disaster; it is a reality of nature where forces from the outside world affect individuals exposed to such phenomenon. In computational psychology domains, computational models were used as tools for understanding human cognitive functions and behavioural patterns. Meanwhile, psychological and cognitive theories as well as empirical studies have provided convergent evidence to identify important factors and psychological attributes that affect the stress level of victims during natural disaster. Therefore, this study implements a formal model (computational model) to understand the current state of victims' stress during natural disaster. From related theories, 22 of basic factors have been established and grouped into 7 main categories that include predisposed factors, resources, individual attributes, appraisal, resilience, coping, and stress. Those factors provide the fundamental knowledge of the behaviours of victims after disaster occurrence. A formal model was developed by using a set of differential equations. Later, this model was simulated by applying related scenarios based on three different cases, namely; 1) a good victim with low level of stress, 2) victim with high level of stress, and 3) victim with moderate level of stress) through the use of Matlab as a programming language. This computational model was then verified using two techniques; 1) logical verification (Temporal Trace Language) and 2) mathematical verification (stability analysis). The experimental results have approximately predicted why victims develop stress differently when facing natural disasters

Time-dependent behaviour of micro-tunneling construction in Queenston shale

The Queenston shale among other shales from southern Ontario exhibits time-dependent deformation behaviour. This behaviour is manifested in the form of volume increase which can cause damages to the hosted underground structures. The time-dependent deformation of rocks can cause cracks in the springline of tunnels, wall inward movement, roof spalling and floor heave, which requires costly remedial measures. The expansion of the existing infrastructures in southern Ontario requires construction techniques, such as micro-tunneling to build new tunnels and pipelines under the existing structures with minimal impact to these structures and to the environment. However, adopting this technique in swelling rocks, such as the Queenston shale requires an evaluation of its feasibility and functionality prior to its application. Accordingly, a comprehensive study that included experimental and numerical investigations was conducted to evaluate the impact of lubricant fluids used in micro-tunneling applications on their time dependent behaviour. The experimental program evaluated the impact of water, bentonite and polymer solutions on the Queenston shale through: i) investigating the influence of lubricant fluids on the time-dependent deformation behaviour of the Queenston shale through performing free swell, semi-confined, and null swell tests on Queenston shale in these fluids, ii) investigating the impact of lubricant fluids on the strength of the Queenston shale utilizing the Brazilian, direct tension, unconfined compression, and triaxial compression tests, before and after soaking in lubricant fluids, and iii) investigating the depth of penetration of lubricant fluids and water into the Queenston shale. It was revealed that the impact of polymer solution was significant in reducing the time-dependent deformation of the Queenston shale compared to bentonite solution and water. The strength of the Queenston shale was remarkably decreased after their continuous exposure to water and lubricant fluids with minimal impact caused by polymer solution. The penetration of lubricant fluids was found smaller compared to water, and a relation was derived to compute the penetration depth of each fluid in Queenston shale with time. The numerical investigation comprised finite element parametric analyses using the derived tests results along with time-dependent deformation model employing computer program PLAXIS 2D. Different pipe diameter, pipe depth, in-situ stress ratio, and waiting time before final grouting were used in the analyses. Accordingly, micro-tunneling was found to be workable and feasible technique to construct tunnels and pipelines in the Queenston shale of southern Ontario. Recommendations to use the appropriate strength of the make concrete; waiting time and the most suitable depth for micro-tunneling applications are given. The results are envisioned to aid in determining whether or not micro-tunneling technique is a feasible construction technique for pipelines / tunnels in Queenston shale of southern Ontario