Investigations towards the development of a novel multimodal fibre optic sensor for oil and gas applications.

Oil and gas (O&G) explorations are moving into deeper zones of earth, causing serious safety concerns. Hence, sensing of critical multiple parameters like high pressure, high temperature (HPHT), chemicals, etc., are required at longer distances. Traditional electrical sensors operate less effectively under these extreme environmental conditions and are susceptible to electromagnetic interference (EMI). Compared to electrical sensors, fibre optic sensors offer several advantages like immunity to EMI, electrical isolation, ability to operate in harsh environmental conditions and freedom from corrosion. Existing fibre optical sensors in the O&G industry, based on step index single mode fibres (SMF), offer limited performance, as they operate within a narrow wavelength window. A novel multimodal sensor configuration, based on photonic crystal fibre (PCF) and utilising a multiwavelength approach, is proposed for the first time for O&G applications. This thesis reports computational and experimental investigations into the new multimodal sensing methodology, integrating both optical phase-change and spectral-change based approaches, needed for multi-parameter sensing. It includes investigations to improve the signal-to-noise ratio (SNR) by enhancing the signal intensity attained through structural, material and positional optimisations of the sensors. Waveguide related, computational investigations on PCF were carried out on different fibre optic core-cladding structures, material infiltrations and material doping to improve the signal intensity from the multimodal sensors for better SNR. COMSOL Multiphysics simulations indicated that structural and material modifications of the PCF have significant effects on light propagation characteristics. The propagation characteristics of the PCF were improved by modifying the geometrical parameters, and microstructuring the fibre core and cladding. Studies carried out on liquid crystal PCF (LCPCF) identified its enhanced mode confinement characteristics and wavelength tenability features (from visible to near infrared), which can be utilised for multi-wavelength applications. Enhancing core refractive index of the PCF improved the electric field confinements and thereby the signal intensity. Doping rare earth elements into the PCF core increases its refractive index and also provides additional spectroscopic features (photoluminescence and Raman), leading to a scope for multi-point, multimodal sensors. Investigations were carried out on PCF-FBG (Fibre Bragg grating) hybrid configuration, analysing their capabilities for optical phase-change based, multipoint, multi-parameter sensing. Computational investigations were carried out using MATLAB software, to study the effect of various fibre grating parameters. These studies helped in improving understanding of the FBG reflectivity-bandwidth characteristics, for tuning the number of sensors that can be accommodated within the same sensing fibre and enhancing the reflected signal for improved SNR. A new approach of FBG sensor positioning has been experimentally evaluated, to improve its strain sensitivity for structural health monitoring (SHM) of O&G structures. Further, experimental investigations were carried out on FBGs for sensing multiple parameters like temperature, strain (both tensile and compressive) and acoustic signals. Various spectroscopic investigations were carried out to identify the scope of rare earth doping within the PCF for photoluminescence and Raman spectroscopy based multimodal sensors. Rare earth doped glasses (Tb, Dy, Yb, Er, Ce and Ho) were developed using melt-quench approach and excitation- photoluminescence emission studies were carried out. The studies identified that photoluminescence signal intensity increases with rare earth concentration up to an optimum value and it can be further improved by tuning the excitation source characteristics. Photoluminescence based temperature studies were carried out using the rare earth doped glasses to identify their suitability for O&G high temperature conditions. Raman spectroscopic investigations were carried out on rare earth (Tb) doped glasses, developed using both melt-quench and sol-gel based approaches. Effect of 785 nm laser excitation on Raman signatures and suitability of rare earth doped materials for fibre-based Raman distributed temperature sensing (DTS) were also studied. Finally, a novel multimodal fibre optic sensor configuration is proposed for the O&G applications, consisting of rare earth doped photonic crystal fibre integrating Bragg gratings and operating in multiple wavelength regimes in a multiplexed fashion. The integrated sensor combination is expected to overcome the limitations of existing sensors with regards to SNR, sensing range and multimodal sensing capability

A Survey on Subsurface Signal Propagation

Wireless Underground Communication (WUC) is an emerging field that is being developed continuously. It provides secure mechanism of deploying nodes underground which shields them from any outside temperament or harsh weather conditions. This paper works towards introducing WUC and give a detail overview of WUC. It discusses system architecture of WUC along with the anatomy of the underground sensor motes deployed in WUC systems. It also compares Over-the-Air and Underground and highlights the major differences between the both type of channels. Since, UG communication is an evolving field, this paper also presents the evolution of the field along with the components and example UG wireless communication systems. Finally, the current research challenges of the system are presented for further improvement of the WUCs

Ultrasensitive, high-dynamic-range and broadband strain sensing by time-of-flight detection with femtosecond-laser frequency combs

Ultrahigh-resolution optical strain sensors provide powerful tools in various scientific and engineering fields, ranging from long-baseline interferometers to civil and aerospace industries. Here we demonstrate an ultrahigh-resolution fibre strain sensing method by directly detecting the time-of-flight (TOF) change of the optical pulse train generated from a free-running passively mode-locked laser (MLL) frequency comb. We achieved a local strain resolution of 18 p{\epsilon}/Hz1/2 and 1.9 p{\epsilon}/Hz1/2 at 1 Hz and 3 kHz, respectively, with largedynamic range of >154 dB at 3 kHz. For remote-point sensing at 1-km distance, 80 p{\epsilon}/Hz1/2 (at 1 Hz) and 2.2 p{\epsilon}/Hz1/2 (at 3 kHz) resolution is demonstrated. While attaining both ultrahigh resolution and large dynamic range, the demonstrated method can be readily extended for multiple-point sensing as well by taking advantage of the broad optical comb spectra. These advantages may allow various applications of this sensor in geophysical science, structural health monitoring, and underwater science.Comment: 20 pages, 4 figure

Current Advances in Internet of Underground Things

The latest developments in Internet of Underground Things are covered in this chapter. First, the IOUT Architecture is discussed followed by the explanation of the challenges being faced in this paradigm. Moreover, a comprehensive coverage of the different IOUT components is presented that includes communications, sensing, and system integration with the cloud. An in-depth coverage of the applications of the IOUT in various disciplines is also surveyed. These applications include areas such as decision agriculture, pipeline monitoring, border control, and oil wells

Decision Agriculture

In this chapter, the latest developments in the field of decision agriculture are discussed. The practice of management zones in digital agriculture is described for efficient and smart faming. Accordingly, the methodology for delineating management zones is presented. Modeling of decision support systems is explained along with discussion of the issues and challenges in this area. Moreover, the precision agriculture technology is also considered. Moreover, the chapter surveys the state of the decision agriculture technologies in the countries such as Bulgaria, Denmark, France, Israel, Malaysia, Pakistan, United Kingdom, Ukraine, and Sweden. Finally, different field factors such as GPS accuracy and crop growth are also analyzed

Optical fibre-based sensors for oil and gas applications.

Oil and gas (O&G) explorations moving into deeper zones for enhanced oil and gas recovery are causing serious safety concerns across the world. The sensing of critical multiple parameters like high pressure, high temperature (HPHT), chemicals, etc., are required at longer distances in real-time. Traditional electrical sensors operate less effectively under these extreme environmental conditions and are susceptible to electromagnetic interference (EMI). Hence, there is a growing demand for improved sensors with enhanced measurement capabilities and also sensors that generates reliable data for enhanced oil and gas production. In addition to enhanced oil and gas recovery, the sensing technology should also be capable of monitoring the well bore integrity and safety. The sensing requirements of the O&G industry for improved sensing in deeper zones include increased transmission length, improved spatial coverage and integration of multiple sensors with multimodal sensing capability. This imposes problems like signal attenuation, crosstalks and cross sensitivities. Optical fibre-based sensors are expected to provide superior sensing capabilities compared to electrical sensors. This review paper covers a detailed review of different fibre-optic sensing technologies to identify a feasible sensing solution for the O&G industry

Marshall Space Flight Center Research and Technology Report 2019

Today, our calling to explore is greater than ever before, and here at Marshall Space Flight Centerwe make human deep space exploration possible. A key goal for Artemis is demonstrating and perfecting capabilities on the Moon for technologies needed for humans to get to Mars. This years report features 10 of the Agencys 16 Technology Areas, and I am proud of Marshalls role in creating solutions for so many of these daunting technical challenges. Many of these projects will lead to sustainable in-space architecture for human space exploration that will allow us to travel to the Moon, on to Mars, and beyond. Others are developing new scientific instruments capable of providing an unprecedented glimpse into our universe. NASA has led the charge in space exploration for more than six decades, and through the Artemis program we will help build on our work in low Earth orbit and pave the way to the Moon and Mars. At Marshall, we leverage the skills and interest of the international community to conduct scientific research, develop and demonstrate technology, and train international crews to operate further from Earth for longer periods of time than ever before first at the lunar surface, then on to our next giant leap, human exploration of Mars. While each project in this report seeks to advance new technology and challenge conventions, it is important to recognize the diversity of activities and people supporting our mission. This report not only showcases the Centers capabilities and our partnerships, it also highlights the progress our people have achieved in the past year. These scientists, researchers and innovators are why Marshall and NASA will continue to be a leader in innovation, exploration, and discovery for years to come

ADAPTIVE MODEL BASED COMBUSTION PHASING CONTROL FOR MULTI FUEL SPARK IGNITION ENGINES

This research describes a physics-based control-oriented feed-forward model, combined with cylinder pressure feedback, to regulate combustion phasing in a spark-ignition engine operating on an unknown mix of fuels. This research may help enable internal combustion engines that are capable of on-the-fly adaptation to a wide range of fuels. These engines could; (1) facilitate a reduction in bio-fuel processing, (2) encourage locally-appropriate bio-fuels to reduce transportation, (3) allow new fuel formulations to enter the market with minimal infrastructure, and (4) enable engine adaptation to pump-to-pump fuel variations. These outcomes will help make bio-fuels cost-competitive with other transportation fuels, lessen dependence on traditional sources of energy, and reduce greenhouse gas emissions from automobiles; all of which are pivotal societal issues. Spark-ignition engines are equipped with a large number of control actuators to satisfy fuel economy targets and maintain regulated emissions compliance. The increased control flexibility also allows for adaptability to a wide range of fuel compositions, while maintaining efficient operation when input fuel is altered. Ignition timing control is of particular interest because it is the last control parameter prior to the combustion event, and significantly influences engine efficiency and emissions. Although Map-based ignition timing control and calibration routines are state of art, they become cumbersome when the number of control degrees of freedom increases are used in the engine. The increased system complexity motivates the use of model-based methods to minimize product development time and ensure calibration flexibility when the engine is altered during the design process. A closed loop model based ignition timing control algorithm is formulated with: 1) a feed forward fuel type sensitive combustion model to predict combustion duration from spark to 50% mass burned; 2) two virtual fuel property observers for octane number and laminar flame speed feedback; 3) an adaptive combustion phasing target model that is able to self-calibrate for wide range of fuel sources input. The proposed closed loop algorithm is experimentally validated in real time on the dynamometer. Satisfactory results are observed and conclusions are made that the closed loop approach is able to regulate combustion phasing for multi fuel adaptive SI engines

Program and Proceedings: The Nebraska Academy of Sciences 1880-2011

PROGRAM FRIDAY, APRIL 15, 2011 REGISTRATION FOR ACADEMY, Lobby of Lecture wing, Olin Hall Aeronautics and Space Science, Session A, Olin 249 Aeronautics and Space Science, Session B, Olin 224 Collegiate Academy, Biology Session A, Olin B Collegiate Academy, Chemistry and Physics, Session A, Olin 324 Chemistry and Physics, Section A, Chemistry, Olin A Biological and Medical Sciences, Session A, Olin 112 Biological and Medical Sciences, Session B, Smith Callen Conference Center Chemistry and Physics, Section B, Physics, Planetarium Junior Academy, Judges Check-In, Olin 219 Junior Academy, Senior High REGISTRATION, Olin Hall Lobby NWU Health and Sciences Graduate School Fair, Olin and Smith Curtiss Halls Junior Academy, Senior High Competition, Olin 124, Olin 131 Teaching of Science and Math, Olin 325 Aeronautics and Space Science, Poster Session, Olin 249 Applied Science and Technology, Olin 325 Aeronautics and Space Science, Poster Session, Olin 249 MAIBEN MEMORIAL LECTURE, OLIN B Dr. Erin Flynn, Nocturnal Manager, Omaha\u27s Henry Doorly Zoo LUNCH, PATIO ROOM, STORY STUDENT CENTER (pay and carry tray through cafeteria line, or pay at NAS registration desk) Aeronautics Group, Conestoga Room Anthropology, Olin 111 Biological and Medical Sciences, Session C, Olin 112 Biological and Medical Sciences, Session D, Smith Callen Conference Center Chemistry and Physics, Section A, Chemistry, Olin A Chemistry and Physics, Section B, Physics, Planetarium Collegiate Academy, Biology Session A, Olin B Collegiate Academy, Biology Session B, Olin 249 Collegiate Academy, Chemistry and Physics, Session B, Olin 324 Collegiate Academy, Chemistry and Physics, Session C, Olin 325 Earth Science, Olin 224 Junior Academy, Judges Check-In, Olin 219 Junior Academy, Junior High REGISTRATION, Olin Hall Lobby Junior Academy, Senior High Competition, (Final), Olin 110 Junior Academy, Junior High Competition, Olin 124, Olin 131 NJAS Board/Teacher Meeting, Olin 219 BUSINESS MEETING, OLIN B AWARDS RECEPTION for NJAS, Scholarships, Members, Spouses, and Guests First United Methodist Church, 2723 N 50th Street, Lincoln, N