Utilization Of Carbon Nanotubes In Electromagnetic Wave Detectors

Direct detection of hydrocarbon by an active source using electromagnetic (EM) energy termed seabed logging (SBL) has shown very promising results. However, currently available electromagnetic wave technology has a number of challenges include sensitivity and frequency matching. This paper presents development of the carbon nanotubes (CNTs) as electromagnetic wave detector due to outstanding properties of carbon nanotubes. They are currently one of the desired materials for advanced technologies. Two types of detectors were developed in this work, carbon nanotube-based (D1) and without nanotube-based (D2) detectors. Various configuration and arrangement for each type of detector were investigated to determine the one with the highest detection measurement and stability of frequency stability of detection system. It was found that 20 turn-coils coil placed at its centre gives the maximum detection of induction voltage, 39.61 mV. However, the 20 turn- coils with CNTs which gives 36.50 mV is the preferred EM detectors due to the stability in frequency of the detection system

A multidisciplinary geophysical approach to recognize and quantify the gas occurrence in the Northern Adriatic

L'Adriatico settentrionale \ue8 caratterizzato da una presenza diffusa di gas nel sottosuolo, testimoniata da vari segni distintivi sul fondo mare e nei sedimenti sottostanti. Nel 2009 e nel 2014, OGS ha effettuato nell'area due campagne di sismica a riflessione 2D , finalizzate ad indagare la relazione tra le emissioni di gas, i cammini di migrazione e l'assetto geologico della regione. Inoltre, si voleva caratterizzare da un punto petrofisico i fluidi all'interno della successione sedimentaria. In questa tesi, due linee sismiche perpendicolari del dataset sono state selezionate ed analizzate. L'obiettivo era la determinazione della distribuzione del gas e la stima della sua concentrazione lungo le due linee sismiche, all'interno della successione sedimentaria Plio-Quaternaria e correlando log di pozzo e attributi sismici. Un approccio multidisciplinare \ue8 stato applicato sia nell'analisi che nell'interpretazione dei dati, integrando l'informazione geologica e quella geofisica. La caratterizzazione del gas nell'area di studio ha due implicazioni importanti: 1) Una valutazione complessiva della presenza di gas e della sua dinamica di migrazione all'interno della successione sedimentaria pu\uf2 vincolare il ruolo delle strutture tetttoniche identificate 2) L'approccio innovativo e multidisciplinare usato pu\uf2 essere applicato in altre aree di studio, caratterizzate dalla presenza di gas nei sedimenti e in simili assetti geologici. Inoltre, considerato il fondale molto basso dell'area, il trasferimento di gas dai sedimenti alla colonna d'acqua e nell'atmosfera potrebbe essere rapido e significativo. Comprendere a fondo i meccanismi di fuoriuscita di gas ha quindi importanti implicazioni climatologiche, dato che il metano, il componente principale del gas nell'area, ha un ruolo di spicco come gas serra.The Northern Adriatic is characterized by widespread occurrence of gas in the subsurface, testified by the presence of fluid related seabed and sub-seabed features (Donda et al., 2015, and references therein). In 2009 and 2014 OGS carried out two 2D multichannel seismic surveys in the area to constrain the relationship between gas emissions, migration paths and the regional geological setting. A further aim was to characterize the gas-charged fluids occurring within the sedimentary succession. Two seismic lines from these datasets were analyzed in the framework of this PhD thesis (GEA project, \u2019Gas Emissions in the Northern Adriatic Sea\u2019). The objective of this thesis is to determine the distribution of gas and estimate its concentration along the two selected perpendicular seismic profiles within the Plio-Quaternary sedimentary succession, through the petrophysical characterization of the sediments with the use of well-log to seismic attributes correlation. A multidisciplinary approach was applied both in the analysis and in the interpretation of the data, through the integration of geological information with geophysical wireline logs and seismic data. The proper characterization of the gas occurrence in the study area has two direct implications: 1. The comprehensive evaluation of both the gas occurrence and its migration within the sedimentary succession will constrain the role of the identified tectonic features; 2. The innovative and multidisciplinary approach used in this thesis could be applied to other areas characterized by gas-charged fluids in similar geological settings. Moreover, due to the shallow water in the Northern Adriatic, the potential transfer of gas from sediment to the water column and then into the atmosphere could be significant. Therefore, understanding the mechanisms of natural gas seepage has important climatological implications, since methane, the main component of the gas in the area (Donda et al., accepted), plays a major role as a greenhouse gas

Measuring and modelling of cross-shore sediment transport and profile evolution on natural beaches

Cross-shore sediment transport is the dominant process causing beach profile evolution. The ability to model cross-shore sediment transport allows prediction of the future beach state be made. Due to a balance between opposing mechanisms, cross-shore sediment transport is difficult to predict. One route to make these predictions is with the development of measurement based parameterisation. This study builds on previousp arameterisationtsh at have relatedc ross-shorev elocity moment (predictorso f suspendeds edimentt ransporta ccordingt o the energeticsa pproacht o sediment transport)t o normalisedd epth( a proxy of cross-shorep osition),t o presenta new shapef unction parameterisationT. he presentp arameterisatiohna s beend evelopedf rom field measurementosf depth-integratedcr oss-shores uspendeds edimentt ransportm easuredd uring a month long field campaigna t SennenC ove, Cornwall, UK. This parameterisationis an improvemento f the previouss hapef unction parameterisationin three key areas;i ) removest he dependencyo n the energetics approach, and so includes all transport mechanisms, ii) incident energy (parameteriseda s breakpointd epth- hb) is considereda, nd so allows this shapef unction to be usedu nder a wide rangeo f energyc onditions,i ii) the swashz one processesa re consideredin detail. The new shapef unction parameterisationis the sum of four components hapef unctions that represenmt eana nd oscillatoryt ransporti n the surf- and shoalingz onea nd on- and offshore transporti n the swash-zoneA. s eachc omponents hapef unction respondsin dividually to energy level, the net-transport shape function responds to varying conditions. Under high-energy conditions the shape function predicts onshore transport in the shoaling zone, offshore transport in the surf zone and onshore transport in the inner swash zone, while under low energy the shape function predicts all onshore transport with a peak outside the breakpoint and in the inner surf-zone. The shapef unction is implementedin a simple heuristicp rofile evolutionm odel that allows the examination of beach behaviour of under varying conditions to be examined over long (decadal) time-scalesP. reliminaryr esultss how that the shapef unction model is able to replicateo nshore and offshoreb ar migration,b ar developmenat nd bar degenerationo ver timescalen ot previously modelled.F uture work will use this model to investigatet he responseto subtletiesi n driving conditions,s ucha s the varying effect of seasonalityc omparedto randoms torms.the Natural Environnient Research Counci

UAV photogrammetry ground control reductions using GNSS

Ph. D. Thesis.Unmanned aerial vehicles (UAVs) are now well-established as platforms for photogrammetric data acquisition. Their advantages, particularly over conventional manned aerial platforms, relate to their low cost, ease of use, rapid deployability and low-level flying for the collection of centimetre-level spatial resolution imagery. Coupled with recent innovations in photogrammetry and computer vision, UAVs equipped with consumer grade digital cameras are now frequently used to generate centimetre-resolution and accuracy mapping products, such as dense point clouds, digital elevation models and orthomosaics. Despite the efficiency of UAV data acquisition, the continued need for ground control implementation for photogrammetric image orientation remains a substantial workflow constraint. In addition to the associated costs, ground control must be implemented strategically, and usually extensively, to ensure photogrammetric products meet the accuracy requirements of large scale mapping, which may or may not be possible given constraints of the intended application. This research uses high precision, UAV-based GNSS (Global Navigation Satellite System) positioning techniques to substantially reduce ground control requirements by directly determining UAV image positions with centimetre-level accuracy and precision. The Precise Point Positioning (PPP) technique is applied and can yield centimetre-level planimetric and decimetre height accuracy photogrammetric mapping without GCPs, whilst the height accuracy can be improved to the centimetre-level using a single GCP. Unlike the standard relative GNSS positioning technique, PPP alleviates all spatial operating constraints associated with the installation and use of a local ground-based GNSS reference station, or the need to operate within the bounds of a permanent GNSS reference station network. Such a workflow simplifies operational logistics, and enables large-scale photogrammetric mapping from UAVs in even the most remote and challenging geographic locations globally. The approach was tested on 11 fixed wing UAV datasets, acquired at two sites in Northumberland, north-east England, which had varying ground control configurations. UAV flight durations, meaning time between launch and landing, were 12-42 minutes. It is shown that the main limitation of UAV-based PPP application is the inherent possibility of GNSS cycle slips and limited observation spans that inhibit the convergence of float ambiguity estimates. Although PPP camera position estimates were biased in such cases, GCPs were still minimised due to the retained precision of the PPP camera position estimates and constraints on the image block.EPSR

OBSERVER-BASED-CONTROLLER FOR INVERTED PENDULUM MODEL

This paper presents a state space control technique for inverted pendulum system. The system is a common classical control problem that has been widely used to test multiple control algorithms because of its nonlinear and unstable behavior. Full state feedback based on pole placement and optimal control is applied to the inverted pendulum system to achieve desired design specification which are 4 seconds settling time and 5% overshoot. The simulation and optimization of the full state feedback controller based on pole placement and optimal control techniques as well as the performance comparison between these techniques is described comprehensively. The comparison is made to choose the most suitable technique for the system that have the best trade-off between settling time and overshoot. Besides that, the observer design is analyzed to see the effect of pole location and noise present in the system

A Review of Resonant Converter Control Techniques and The Performances

paper first discusses each control technique and then gives experimental results and/or performance to highlights their merits. The resonant converter used as a case study is not specified to just single topology instead it used few topologies such as series-parallel resonant converter (SPRC), LCC resonant converter and parallel resonant converter (PRC). On the other hand, the control techniques presented in this paper are self-sustained phase shift modulation (SSPSM) control, self-oscillating power factor control, magnetic control and the H-∞ robust control technique

A Review of Resonant Converter Control Techniques and The Performances

paper first discusses each control technique and then gives experimental results and/or performance to highlights their merits. The resonant converter used as a case study is not specified to just single topology instead it used few topologies such as series-parallel resonant converter (SPRC), LCC resonant converter and parallel resonant converter (PRC). On the other hand, the control techniques presented in this paper are self-sustained phase shift modulation (SSPSM) control, self-oscillating power factor control, magnetic control and the H-∞ robust control technique

State-Feedback Controller Based on Pole Placement Technique for Inverted Pendulum System

This paper presents a state space control technique for inverted pendulum system using simulation and real experiment via MATLAB/SIMULINK software. The inverted pendulum is difficult system to control in the field of control engineering. It is also one of the most important classical control system problems because of its nonlinear characteristics and unstable system. It has three main problems that always appear in control application which are nonlinear system, unstable and non-minimumbehavior phase system. This project will apply state feedback controller based on pole placement technique which is capable in stabilizing the practical based inverted pendulum at vertical position. Desired design specifications which are 4 seconds settling time and 5 % overshoot is needed to apply in full state feedback controller based on pole placement technique. First of all, the mathematical model of an inverted pendulum system is derived to obtain the state space representation of the system. Then, the design phase of the State-Feedback Controller can be conducted after linearization technique is performed to the nonlinear equation with the aid of mathematical aided software such as Mathcad. After that, the design is simulated using MATLAB/Simulink software. The controller design of the inverted pendulum system is verified using simulation and experiment test. Finally the controller design is compared with PID controller for benchmarking purpose

Toward high-definition reservoir characterization

A new methodology for high resolution reservoir characterization is proposed. It combined the advantages of the surface seismic (low resolution, large coverage) and crosswell seismic (improved resolution, small coverage).;The process involves deconvolution of a low resolution signal (surface seismic traces) into a high resolution crosswell seismic trace. The problem has multiple solutions and an analytical solution is hard or difficult to be developed.;This project proved that it is possible to predict high-resolution crosswell seismic traces using low-definition surface seismic traces. The statistical comparison between the real and the synthetic crosswell seismic traces gives confidence that future work in this area worth the effort.;The ultimate goal of this work is to be a part of an intelligent tool that will be able to provide, based on surface seismic, a volumetric, detailed picture of rock and fluid characteristics across the field