Browsing by Author "Park, Simon S."
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- ItemOpen AccessA study on the fluid-structure interaction and biomechanical effects of the eye on iop measurements using a vibration based tonometry(2010) Salimi, Samira; Freiheit, Theodor; Park, Simon S.Glaucoma, the second leading cause of blindness worldwide, is a group of diseases of the optic nerve that is generally characterized by an increase of intraocular pressure (IOP). Early diagnosis and treatments through eye exams may prevent the visual damage from glaucoma. Monitoring the IOP is one of the most common ways for detecting the progression of this disease as high IOP can lead to glaucoma and vision loss. This study investigates the correlation between IOP and vibration characteristics of the eye to examine the potential of measurements of variation in these characteristics as an estimate in changing IOP. In this regards, a finite element model of the eye subjected to vibration was developed. This model led to solve a problem of fluid-structural interactions of a generally spherically shaped shell system. The structural dynamic effects due to change in pressure of the fluid were also examined. The finite element model was verified by comparing its vibrational characteristics with the results of an experimental modal analysis on an elastic spherical shell filled with water. The numerical model was then used to analyze a finite element model of a pig eye. The results of the numerical model were supported by performing a series of experimental modal analysis (EMA) on the enucleated pig eyes. The comparisons between the finite element model and the experimental results showed that an increase in the IOP results in an increase the natural frequencies of the eye. The influences of different biomechanical properties of the eye were also investigated through a statistical analysis on the pig eyes and a design of experiment analysis on the finite element model of the eye. A non-contact vibration based tonometery was designed based on the correlations between IOP and natural frequencies of the eye. The applicability of the design was examined through a finite element analysis. The eye in the design was excited through an air impulse and the acoustic pressure waves resultant from the vibrations of the eye were recorded through an array of pressure sensors that were located around the front of the eye. Dynamics of the eye were then analyzed through acquiring the frequency contents of the measurements at the sensors. The influences of the different design variables were also investigated through an optimization study.
- ItemOpen AccessCatalytic Aromatization of Paraffin-Rich Oil under Methane Environment(2018-09) Jarvis, Jack; Song, Hua; Chen, Zhangxing; Park, Simon S.Naphtha fractions obtained from petroleum refinement contain an abundant mixture of hydrocarbons including paraffins, naphthenes, aromatics, and even olefins. n-paraffins are the largest constituents of such oils and are the most undesirable because of their poor octane values and low economic value as chemical feeds. Thus, scientific research aims to convert these components into more valuable components with higher octane numbers for fuels and/or high value chemical precursors used for chemical synthesis. Current naphtha reforming processes require an element of hydrocracking to reduce the number of larger carbon number components but hydrogen is expensive to obtain through the current process of steam reforming natural gas and so an alternative source of hydrogen is also desirable. One such source of hydrogen is methane, a naturally, occurring, and cheap alternative. However, the activation of methane, the most stable of the hydrocarbons, is difficult to achieve. This research aims at the conversion of naphtha feeds (rich in n-paraffins) to more valuable benzene, toluene, and xylenes (BTX) whilst using methane as a hydrogen source through heterogenous catalysis. Catalysts are screened to gauge those with the highest performance and then the effect of methane is also probed. This approach was conducted for two different fractions of naphtha as provided by the petrochemical industry with very different components. A model compound study was also conducted to enable a more comprehensive understanding of the processes involved during upgrading.
- ItemOpen AccessA contribution to risk-informed inspection and maintenance planning for unpiggable pipelines subject to internal corrosion(2020-12-10) Melo Gonzalez, Carlos Alberto; Dann, Markus R.; Hugo, Ronald J.; Groth, Katrina M.; Yanushkevich, Svetlana N.; Ziadé, Paul; Park, Simon S.Pipelines are the safest transportation mode for hydrocarbons, but internal corrosion is still a major cause of failure for energy pipelines. Inspection and repair strategies are implemented to avoid pipeline failures and their consequences. In-line inspection is the most detailed examination technique for pipelines, but almost half of existing pipelines are unpiggable and cannot be inspected using this technique. Direct assessment, based on models that numerically assess corrosion in a pipeline, was developed to overcome this limitation and to facilitate inspection at certain sites. However, most of these models do not take localized corrosion into consideration, which is the main cause of pipeline failure. Industry standards provide guidance for selecting inspection sites based on the results of direct assessment models. However, this process is based only on the likelihood of pipeline failure and can lead to decisions which imply elevated risk and increased pipeline lifecycle costs. The aim of this dissertation is to expand the state of knowledge in risk-based inspection and maintenance planning for upstream unpiggable pipelines subject to internal corrosion. The research focuses on unpiggable pipelines in production and gathering systems operated in the upstream oil and gas industry. A framework for probabilistic risk and integrity assessment of unpiggable pipelines is developed. The framework combines advanced flow and corrosion models with risk-based inspection and maintenance planning. It also includes uncertainty analysis and lifecycle-cost optimization. An extreme value analysis is developed to model localized corrosion and microbiologically-influenced corrosion, which are the main causes of internal corrosion failure in pipelines. A method for decision optimization of unpiggable pipeline inspections based on the value of information is proposed. For maintenance decision optimization at specified safety levels, the research considers both risk-constrained optimization and lifecycle-cost optimization. The research outcomes provide pipeline operators with a methodology for developing optimal inspection and maintenance plans, while maintaining adequate safety levels.
- ItemOpen AccessDevelopment and analysis of the precision micro milling system(2006) Chae, Jaehee; Park, Simon S.The miniaturization of machine components plays a very important role in the future technological development of a broad spectrum of product owing to various advantages low material cost, portability, implant, lower power consumption and higher heat transfer since their surface-to-volume ratio is very high. In particular, one of the manufacturing processes for small parts is micro-mechanical machining. Similar to macro machining processes, the micro machining process can create three dimensional parts on a micro scale with various engineering materials (i.e. metallic alloys, ceramics, plastics) using miniature tools. The micro machining processes have several unique elements such as small size tools, high spindle speed, and miniaturized machine tools. This thesis focuses on several aspects of micro machining operations in order to improve the performance of micro machining process. The survey of the current efforts in micro-mechanical machining investigated various aspects such as current research directions, limitations, similarities and differences between macro and micro in order to understand the fundamental knowledge of micro mechanical machining. The prediction of the joint dynamics is vital to evaluate the micro machine tool performances through its dynamics because the joint plays significant roles in the micro system's behavior because the size of joint is relatively close to the assembled system. The fastener joint dynamics are identified with the classic receptance coupling technique. The proposed method is enhanced by identifing the joint dynamics between substructures through experimental and finit lement analyse . This novel identification method increase the accuracy of the dynamic prediction of machine tool, by minimizing numerical errors and the problems associated with convergence. Various experimntal dynamics and micro cutting tests are performed to verify the proposed methods. The fragility of micro tools would require the operation to be monitored to avoid excessive forces and vibrations that will significantly affect the overall paii and tool quality. In addition, the high rotational speeds represent high bandwidth requirements to measure micro cutting forces. In this thesis, a miniaturized milling system, and the accurate high bandwidth measurement of micro cutting forces using a 3-axis miniature force sen or and accelerometers are also developed in order to monitor the micro cutting forces accurately. The developed miniaturized milling system can fabricate micro parts with various engineering materials and micro tools within an 8 ?m resolution movement and an 80,000 rpm spindle speed. Since the inherent dynamics of the workpiece and overall machine tool affects the frequency bandwidth of sensors, the expanded Kalman filter is employed to compensate for unwanted dynamics by fusing the force sensor and accelerometer signals to increase the frequency bandwidth of the micro cutting forces measurement system.
- ItemOpen AccessDevelopment of a novel micropump system(2008) Xiao, Xiaojun; Park, Simon S.; Freiheit, Theodor
- ItemOpen AccessDevelopment of Non-contact Laser Ultrasonic System for Nondestructive Evaluation(2018-04-26) Mirsadeghi, Seyed Mehdi; Hugo, Ronald J.; Park, Simon S.; Kim, Seonghwan; Sun, Qiao; Murari, KartikeyaThe development of cracks and corrosion in pipelines could pose a potential hazard to the community and the pipeline industry. Particularly for buried or insulated pipelines, corrosion and other types of defects may remain invisible unless the pipe is physically excavated or the insulation layers are removed. In this regard, advanced guided wave techniques are rapidly growing due to the advantages that they offer over traditional direct assessment inspection methods. To overcome the challenges associated with the use of conventional ultrasonic techniques, a non-contact laser-based non-destructive evaluation system is proposed in this research work. Compared to conventional ultrasonic transducers, a laser-based technique remains functional at elevated temperatures and can result in high-resolution damage visualization. Using the laser Doppler vibrometer as the ultrasonic detection subsystem, and the pulsed Nd:YAG laser for the ultrasonic generation, a complete non-contact ultrasonic system was implemented. The pulsed laser heats the surface of the specimen, and as a result, thermal and ultrasonic waves are generated in the structure. A reliable numerical model was created using the finite element analysis. The numerical results were validated with experiments in the time and frequency domains. The application of a Nd:YAG laser for ultrasonic wave generation was limited due to a lack of repeatability in the signals and low signal-to-noise ratio and potential damages to the surface. Instead, a piezoelectric transducer in combination with the laser Doppler vibrometer was used to enhance defect identification in aluminum plates. The results show that the proposed method can successfully identify the location and the approximate shape of hidden defects.
- ItemOpen AccessEnhancing Tribological Properties of Metallic Sliding Surfaces through Micro Multi-texturing Techniques(2019-07-10) Reséndiz-Pérez, Jaime De Jesús; Park, Simon S.; Egberts, Philip; Park, Simon S.; Egberts, Philip; Cheng, Yufeng Frank; Ramírez Serrano, Alejandro; Nassar, Nashaat N.; Dunn, Alison C.Friction reduction is important for minimizing energy loss and improving the life of sliding components. Surface texturing is considered an effective way to control the wear and friction on these components. In this research, textured surfaces were created on aluminium workpieces using the tilted micro end milling technique. A flat end mill was used to generate asymmetric dimples. A different series of symmetric dimpled surfaces were also machined using a single crystal diamond cutter. Cutting forces were modelled and compared with the experimental results. On the symmetric dimpled surface, a multi-scale texture process was carried out on the dimples to create a smaller scale roughness through a High-Velocity Abrasive Machining process. A reciprocating tribometer, based on a piezoelectric table dynamometer and a hemispherical ruby counter surface, was used to evaluate friction coefficients under both dry and lubricated sliding conditions. Asymmetric dimples exhibited directional friction effects. For multi-scale textured surfaces, it has been observed a greater reduction in the friction coefficient under lubricated conditions when compared with symmetrical dimples. To gain insight into the mechanism of friction reduction for these surfaces, a series of 2D simulations were performed. These simulations showed that the mechanism of friction reduction is attributed to the ability of dimples to increase the pressure of the lubricant in the contact region resulting from the fluid flow between the sliding surfaces. Moreover, a substantial decrease in the depth of the dimples on worn surfaces was observed, suggesting that entrapment of wear particles within the surface texture features may also influence the measured friction coefficient. Analysis of the wear track depth showed that surface texturing also has a beneficial influence on the calculated Archard wear coefficient.
- ItemOpen AccessEvaluation of Strategies To Reduce Tribocorrosion of Steel Components(2020-04-30) Wong, Brandon Christopher; Egberts, Philip; Park, Simon S.; Cheng, Y. Frank; Dann, Markus R.In oil and gas applications, such as for rod pumps used in oil extraction, metallic components are often subjected to corrosive environments and simultaneously abraded by sand. This presents a serious problem as wear reduces efficiency and necessitates the replacement of parts, resulting in increased costs. The purpose of this thesis is to examine strategies for reducing tribocorrosion, including boronizing treatment processes for steels, and using friction reducers and chemical additives in pipelines carrying fracking fluid. The tribological behaviour of uncoated samples, coated samples, and pipe segments were examined in sliding under both dry and corrosive conditions. 0.5M NaCl solution and fracking fluid referred to as high Total Dissolved Solids (TDS) water was used in conjunction with a potentiostat to artificially induce electrocorrosion. Friction coefficients were determined through the use of a home-built linear reciprocating tribometer, and wear coefficients were calculated using an optical profilometer and hardness testing. Additionally, Energy Dispersive X-ray Spectroscopy (EDS) was employed to perform chemical characterisation of tribofilms and corrosion by-products. From the experiments, it was discovered that sample boron-doped boronized steels yielded the lowest friction coefficient (μ = 0.189±0.003) and lowest pseudo-wear coefficient (k = [5.38±0.17]*10^-8 MPa^-1) in dry sliding. This same coating also showed reduced friction with enhanced corrosion in 0.5M NaCl as opposed to AISI 1018 steel which had worse friction performance under corrosion. From the EDS studies, a mechanism was hypothesized for the cause of friction reduction for corroding boronized steels; sliding leads to the wearing of a thin oxide film produced during corrosion which then acts as a lubricant or an antiwelding surface. From tests performed on steel pipe segments, it found that DynaRate 6524 was the most effective friction reducer in high TDS water, decreasing friction by 20% while DWP 621 on the contrary hindered friction performance resulting in a 20% increase in friction. DyanRate 6524 did not affect wear rates significantly whereas DWP 621 increased wear. It was also observed that electrically-induced corrosion poorly affected the friction performance of DynaRate 6524 friction reducer, however, CalGuard 3100 oxygen scavenger which is meant to inhibit corrosion had no affect on the friction performance of DynaRate 6524.
- ItemOpen AccessHigh-Performance, Room Temperature Hydrogen Sensing With a Cu-BTC/Polyaniline Nanocomposite Film on a Quartz Crystal Microbalance(2019-01) Abuzalat, Osama; Wong, Danny; Park, Simon S.; Kim, SeonghwanIn this paper, we demonstrate a high-performance hydrogen sensor under ambient conditions by growing a Cu-BTC/polyaniline (PANI) nanocomposite film on a quartz crystal microbalance (QCM) using intense pulsed light. The QCM was first sputter coated with a 200-nm-thin layer of copper. The copper layer was then oxidized by sodium hydroxide and ammonium persulfate. A solution containing the organic ligand (BTC) and PANI was then dropped and dried on the copper hydroxide surface of a QCM with intense pulsed light which resulted in Cu-BTC/PANI nanocomposite film on a QCM. The gas sensing performance of the Cu-BTC film and Cu-BTC/PANI composite film was compared under ambient conditions. It was found selectivity and sensitivity of the Cu-BTC/PANI nanocomposite film to hydrogen were significantly improved. In addition, a fast response time (from 2 to 5 s), operation at room temperature even in the presence of high relative humidity (up to 60%), good repeatability were achieved with the Cu-BTC/PANI nanocomposite film-grown QCM sensor.
- ItemOpen AccessIn-Situ Modal Response Characterization of Pipe-Structures Through Reynolds Number Variation(2018-09-13) Chen, Haobin; Hugo, Ronald J.; Park, Simon S.; Wood, David H.In this investigation, an in-situ method of system excitation is explored experimentally. The modal characteristics of externally-supported pipe structures are investigated by varying the flow Reynolds number (Red) with hydrodynamic pressure fluctuations due to fully developed turbulent pipe-flow providing a varying excitation source on the internal pipe wall. During experiments, time series records of single-point fluctuating wall pressure and multi-point wall vibrations are collected. Power spectral density functions of both wall pressure fluctuation and wall vibration are computed at each discrete Reynolds number. Visualization of the computed power spectral density functions with flow Reynolds number are then used for system characterization. A comparative analysis of the data sets collected for both acrylic and ABS pipe show that the pressure spectra are similar, while the vibration spectra change significantly. Pressure spectra reveal a character whereby the magnitude of the spectra increase with increasing Reynolds number. A comparison of in-situ results to those obtained using traditional impact response tests show that the vibration spectra collected through Reynolds number variation successfully capture the modal characteristics of the pipe-structure. Both acoustic analysis to determine the vibration source and preliminary health diagnostics investigations for both loss-of-fluid and loss-of-material events are performed.
- ItemOpen AccessIntraocular pressure measurements using vibration based non-contact tonometry(2009) Farshidi, Reza; Park, Simon S.; Freiheit, Theodor
- ItemOpen AccessInvestigation of chatter in micro milling operating(2010) Rahnama, Ramin; Park, Simon S.There has been an increasing demand for fabricating miniature components in recent years. The application of micro parts in different fields, such as lab-on-chips, micro sensors and actuators, and biomedical implants, resulted in the development of various micro manufacturing methods. Micro mechanical machining is one of the newly developed techniques that has several benefits over conventional micro fabrication methods. Unlike in conventional photolithographic methods, micro mechanical machining can provide the required flexibility to fabricate complex 3D geometries out of different engineering materials utilizing miniature end mills. However, chatter instability is a major challenge in the development and commercialization of the micro milling operation. Chatter is a self-excited vibration that causes rough surface finish and dimensional inaccuracy. Although chatter in macro machining has been studied very well in past decades, the effect of micro milling forces, such as process damping and ploughing on chatter, have not been investigated yet. In order to investigate the chatter in high speed micro milling processes, this research extends current macro milling chatter models with the latest micro milling processes. Several contributions to the chatter investigation in micro milling operation are presented in this research. The effect of process damping to increase the stability at lower rotational speeds is investigated. Also the ploughing forces are considered on the chatter stability model in micro milling. Due to very high rotational speeds in micro milling operation, the dynamics and cutting coefficients are not constant. In order to tackle changing parameters, the robust chatter stability is developed which is based on the edge theorem to suppress chatter vibrations. The experimental tests have been performed to support the proposed model and simulation results.
- ItemOpen AccessInvestigation of Intensive Pulsed Light Sintering for Conductive Hybrid Copper Ink(2019-09-03) Kockerbeck, Zachary; Park, Simon S.; Kim, Seonghwan; Lee, Jihyun; Hill, Josephine M.With the increasing demand for flexible electronic devices in applications such as OLED screens and wearable technologies, there is a large need to find improved manufacturing methods in order to reduce costs and increase reliability. With traditional photolithography methods relying on slow and costly processes, the printed electronics industry is becoming a popular alternative. The deposition of flexible, electrically conductive electrodes and circuits onto polymeric materials via a printing technology such as, screen and inkjet printing, is becoming an attractive alternative due to ease of use, system adaptability, processing time, and roll to roll scalability. Most conductive nanoparticle-based ink technologies rely on silver nanoparticles due to their low electrical resistivity and high oxidation resistance; however, this method creates inks that are relatively expensive. In this study, a novel copper nanoparticle-based conductive ink is developed for use with conductive ink-based printing technologies and is designed to replace silver nanoparticles due to the immense cost savings. Novel processing techniques are used to increase oxidation resistance and flexibility along with minimizing resistivity. To prevent thermal damages to low glass transition temperature polymeric substrates, an intensive pulsed light (IPL) technique is used to sinter the hybrid ink in order to induce conductivity. To optimize the sintering process, the IPL technique is then modeled in order to determine the thermal characteristics during the sintering process and to illustrate the geometric changes that occur during sintering. These simulations are then used to predict a resistivity for pure copper nanoparticle films of 6.8 μΩ·cm (~4x bulk copper). Copper ink on its own is also prone to thermal cracking, resistivity increases with bending, and oxidation over time. To mitigate these issues, a hybrid copper ink is created by adding various components such as graphene nanoplatelets (GNP) and silver. This hybrid ink demonstrated an improvement in flexibility and durability for bending performance along with greatly increased oxidation resistance. Another variation of the hybrid copper-silver-graphene (CSG) ink is also explored by doping the material with various low melting temperature metals, known as field metals. These field metals are shown to increase overall flexibility and demonstrate self-healing characteristics. Since stretching and bending processes in printed electronics result in microcracking over time, the inks need to be healed in order to maintain resistance properties. To achieve this self-healing, IPL re-sintering is done on the field metal infused inks. The process is shown to demonstrate complete self-healing without damage to the remaining film and underlying substrate. In order to make these films useful for circuit applications, a process called selective IPL sintering is utilized to micropattern the hybrid ink films into useful conductive patterns. The proposed method is then demonstrated by producing strain sensors in a simple two-step process. Therefore, this work presents the creation and optimization of a novel copper based conductive ink that can be used in various printed electronic applications. The various additives in the ink create a flexible, low cost, oxidation resistant, and even healable conductive ink that will aid in reducing industry costs and increase reliability for various electronics.
- ItemOpen AccessInvestigation of micro milling processes(2010) Malekian, Mohammad; Park, Simon S.Micro mechanical machining is conceived by many as the most versatile method of fabricating miniaturized components in complex three-dimensional shapes from a variety of engineering materials. Although this method has several advantages, such as simplicity and flexibility, compared to photolithographic based methods of micro fabrications, it still faces several challenges. The mechanism of material removal in the micro scale is different from that of conventional macro machining, due to various aspects of material behaviour, such as the presence of a critical chip thickness, elastic recovery, ploughing and size effects, resulting in increased cutting forces and limited productivity. Furthermore, micro tools are small and fragile and can be easily worn and subject to catastrophic failures due to excessive forces and vibrations. Therefore, the prediction and measurement of the cutting forces, as well as monitoring of the micro tool and machining conditions, are imperative. This research is aimed at the modelling of the material removal in micro mechanical machining, especially for micro milling operations. Micro scratch and orthogonal cutting tests are employed to obtain fundamental material behaviour, investigate size effect and identify parameters, such as the elastic recovery, flow stress and friction coefficient. A novel formulation for the critical chip thickness is suggested and experimentally verified. The identified parameters are used in a new mechanistic cutting force model developed for micro milling operations that considers the effects of critical chip thickness, elastic recovery, ploughing forces, tool dynamics and tool run-out. The tool tip dynamics are indirectly obtained using the receptance coupling method. The cutting and ploughing constants for the mechanistic force model are identified from the experimental cutting data, which are measured using a table dynamometer. The expanded Kalman Filter method is employed to compensate for unwanted dynamics of the table dynamometer for accurate measurement of high-speed micro milling forces. A tool wear monitoring scheme that fuses the signals from various sensors, such as a force sensor, accelerometers and an acoustic emission sensor, through a neuro-fuzzy algorithm is utilized to increase the frequency bandwidth of measurement and effectively monitor the tool conditions. The effectiveness of fusing different sensors for monitoring is investigated. This research is important for various micro machining operations in the selection of the optimal machining parameters, in order to obtain the desired productivity and surface quality while maintaining the longevity of micro tools.
- ItemOpen AccessInvestigation of Sonochemical Treatment of Ultrasound-assisted Cavitation of Heavy Hydrocarbon(2020-09-24) Kim, Bomin; Park, Simon S.; Song, Hua; Mohamad, A. A.Heavy oil from the oil sands production poses several limitations on transportation through pipelines and during processing into refined products due to its high viscosity. Partial upgrading of heavy oil targets meeting the pipeline specification with reduced viscosity with minimum diluent addition and provides higher valued hydrocarbon products. This study aims to investigate the viability of cavitation-assisted upgrading of heavy hydrocarbon with a proprietary additive at low temperature and ambient pressure. This study uses 20 kHz ultrasound through an ultrasonic horn to induce cavitation, also known as sonication. Cavitation is a phenomenon comprising of formation, growth and collapse of bubbles in a liquid medium. Collapse of bubbles lead to extreme conditions, creating regional hotspots capable of breaking chemical bonds and generation of free radicals. This study uses n-hexadecane (C16) as a model molecule. The effect of sonication showed a significant change in the conversion of n-hexadecane. For the samples treated with the additives at 230℃ under sonication, the conversion of n-hexadecane was 5.0±3.0%. The additives with decalin at 230℃ under sonication resulted in 9.3±0.7% conversion of n-hexadecane. The conversion of n-hexadecane corresponding to the modeling of cavitation-induced cracking at 25℃ and 250℃ were 0% and 3.7%, respectively. The pressure waves induced by sonoprobe excitations were measured experimentally with the acoustic emission sensor and high sampling rate data acquisition system. Using the obtained calibration constant of 1582.7 Pa/mV, the experimental acoustic pressure was 6.33 MPa which varied 6.79% from the theoretical acoustic pressure of 6.79 MPa. Cavitation has been extensively studied in the field of research in heavy oil. Cavitation is viewed as an effective and inexpensive alternative to initiate and enhance chemical reactions. Chemical and physical transformations induced by cavitation showed its possibility for enhancing cracking of petroleum feedstock. Cracking of petroleum feedstock includes yield in light and middle distillates, breakage of asphaltene contents and reduction in asphaltene agglomeration, reduction in sulfur, nitrogen and metals. The applications of cavitation for cracking have shown to improve the quality of heavy oil and reduce viscosity and density of heavy oil. This makes cavitation promising for partial upgrading of heavy oil.
- ItemOpen AccessMagnetically Aligned Iron Oxide/Au Nanoparticles Decorated Carbon Nanotube Hybrid Structure as Humidity Sensor(American Chemical Society, 2015) Lee, Jaewook; Mulmi, Suresh; Thangadurai, Venkataraman; Park, Simon S.
- ItemOpen AccessMicro and nano mechanical machining of soda lime glass(2010) Sajjadi, Mazhdeh; Park, Simon S.
- ItemOpen AccessMicro-end mill tool tip dynamics prediction and orbital control(2008) Mascardelli, Brock; Freiheit, Theodor; Park, Simon S.
- ItemOpen AccessNano-Catalytic In-Situ Upgrading and Enhanced Recovery of Heavy Oil from Carbonate Reservoirs(2020-05) Elahi, Seyed Moein; Pereira-Almao, Pedro R.; Chen, Zhangxing; Moore, Robert Gordon Gord; Chen, Shengnan; Park, Simon S.; Varfolomeev, MikhailThe current low oil price conditions and the decline in conventional oil reserves as well as the recent concerns on greenhouse gas emissions have motivated researchers and industries to investigate development of novel technologies to produce from heavy oil and bitumen reservoirs. In this thesis, heavy oil recovery from carbonate reservoirs is studied by using an in-situ upgrading technology (ISUT). In this technology, an aboveground vacuum distillation unit is used to separate the vacuum residue from the produced oil, which is a high molecular weight (low quality) cut of oil. Nano-catalysts are then dispersed into the vacuum residue (VR) and are re-injected in the reservoirs, along with hydrogen. By injecting VR, catalyst, and hydrogen, the catalytic nano-particles deposit in the rock around an injection well, where the upgrading reactions occur. Subsequently, the produced light hydrocarbons and gases from the upgrading reactions help to enhance the heavy oil displacement toward production wells. In this thesis, three main steps of the ISUT process are explored. Initially, a computational fluid dynamics study is implemented to model the VR and hydrogen multiphase injection into reservoirs, primarily to ensure that phase segregation does not happen in injection wells. Afterwards, catalytic hydrocracking reactions are analyzed comprehensively. A reaction kinetic model is developed, and upgraded products are characterized carefully. Lastly, with the aid of a novel continuous experimental setup, heavy oil displacement in zones farther from a reaction zone is studied. It is found that by injecting the recovered vacuum residue, instead of steam as a conventional heat carrier, to the reservoirs, the required energy for the catalytic upgrading reactions is provided. In addition to the heat propagation by exothermic hydro-upgrading reactions, the dissolution and diffusion of light upgraded liquid and gaseous products improve the recovery of heavy oil. Finally, by enhancing oil recovery and permanently upgrading heavy oil in one single stage, in- situ upgrading and recovery of heavy oil by the ISUT process can potentially offer a novel solution to the current challenges of the unconventional heavy oil and bitumen production.
- ItemOpen AccessNanoporous Microcantilevers with Plasmonic Absorbers for Photothermal Infrared Spectroscopy(2019-05-13) Simin, Nicholas; Kim, Seonghwan; Kim, Seonghwan; Dalton, Colin; Sanati-Nezhad, Amir; Park, Simon S.A nanoporous anodic aluminum oxide (AAO) bimetallic cantilever enhanced by a gold coating on the nanopores creates a plasmonic crystal structure. The fabricated sensor is used for photothermal cantilever deflection spectroscopy (PCDS). Explosive compounds tested, showed spectra identifying explosive compounds by their characteristic wavelengths. Through a two-step anodization process, photolithography, and bimetallic and plasmonic coatings, a sensitive photothermal microcantilever was fabricated. The bimetallic layer thickness was optimized through analytical calculations. The ideal plasmonic layer thickness was found through experimentation. Molecules adsorbed onto the cantilever surface had their mass quantified through a measured change in 2nd mode resonant frequency. Simultaneously, the molecules were identified by high power infrared (IR) spectroscopy. For standoff spectroscopy, a plasmonic enhanced AAO cantilever was shown to improve characteristic peak depth 10-fold and 7-fold compared to silicon and AAO bimetallic cantilevers, respectively. The limit of detection (LOD) of the plasmonic AAO cantilever was determined to be 63.42 ng/cm2.