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IEEE Conference on Wireless Communications and Networking

作者： Ibrahim M. Abou-Shehada Ali H. Muqaibel Wessam Mesbah Ki-Hong Park Mohamed-Slim Alouini Electrical Engineering Department King Fahd University of Petroleum and Minerals Dhahran Saudi Arabia Electrical Engineering Department Center for Communication Systems and Sensing King Fahd University of Petroleum and Minerals Dhahran Saudi Arabia Electrical and Computer Engineering Program King Abdullah University of Science and Technology Thuwal Saudi Arabia

ISBN: (数字)9798350303582

ISBN: (纸本)9798350303599

Indoor positioning systems (IPS) are gaining higher attention recently due to the increased demand for indoor location aware services. Visible light communication (VLC) is a promising technology to use for IPS. In particular, received signal strength (RSS) based visible light positioning (VLP) systems are gaining high attention due to their low complexity and cost, in addition to higher positioning accuracy compared to their radio frequency (RF) counterparts. One of the main challenges in RSS based VLP systems is encountered when the receiver (the target) is tilted and not placed in parallel with the transmitters (the anchors). RSS based trilateration techniques require a computationally expensive and time-consuming process to solve the nonlinear problem of tilted receivers. Fingerprint based systems generally provide high positioning accuracy with short positioning time, and maybe used to circumvent the need to deal with the high complexity associated with tilted receivers. However, the design of a fingerprinting VLP system for tilted receiver has not been explored yet as far as receivers with a single photodetector (PD) are concerned. In this work, a fingerprint based VLP system for tilted receivers using artificial neural networks (ANN) is proposed, where different types of input features for training the positioning algorithm are studied. We show that using the components of the normal vector to the PD's surface in addition to RSS values provides an excellent positioning accuracy with an average positioning error of 25.41 cm and a remarkably low average positioning time less than $\mathbf{5} \boldsymbol{\mu} \boldsymbol{s}$ . In addition, important research directions for future work are discussed.

关键词： Training Accuracy Receivers Artificial neural networks Fingerprint recognition Vectors Real-time systems

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Implementation of contact line motion based on the phase-field lattice Boltzmann method

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Physical Review E 2024年第4期109卷 045307-045307页

作者： Long Ju Zhaoli Guo Bicheng Yan Shuyu Sun Computational Transport Phenomena Laboratory (CTPL) King Abdullah University of Science and Technology (KAUST) Thuwal 23955-6900 Kingdom of Saudi Arabia Institute of Interdisciplinary Research for Mathematics and Applied Science Huazhong University of Science and Technology Wuhan 430074 China Energy Resource and Petroleum Engineering Program Physical Science and Engineering Division King Abdullah University of Science and Technology (KAUST) Thuwal 23955-6900 Kingdom of Saudi Arabia

This paper proposes a strategy to implement the free-energy-based wetting boundary condition within the phase-field lattice Boltzmann method. The greatest advantage of the proposed method is that the implementation of contact line motion can be significantly simplified while still maintaining good accuracy. For this purpose, the liquid-solid free energy is treated as a part of the chemical potential instead of the boundary condition, thus avoiding complicated interpolations with irregular geometries. Several numerical testing cases, including droplet spreading processes on the idea flat, inclined, and curved boundaries, are conducted, and the results demonstrate that the proposed method has good ability and satisfactory accuracy to simulate contact line motions.

关键词： Contact line dynamics Wetting Lattice-Boltzmann methods

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Preliminary Result of Rayleigh Wave Tomography beneath Jailolo Volcanic Complex, North Moluccas, Indonesia using Ambient Noise 9

Preliminary Result of Rayleigh Wave Tomography beneath Jailo...

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9th Asian Physics Symposium 2021, APS 2021

作者： Vita, A.N. Zulfakriza Martha, A.A. Rohadi, S. Heryandoko, N. Milkerreit, C. Master Program of Earth Sciences Faculty of Earth Sciences and Technology Institut Teknologi Bandung Bandung Indonesia Global Geophysics Research Group Faculty of Mining and Petroleum Engineering Institut Teknologi Bandung Bandung Indonesia Center for Earthquake Science and Technology Institut Teknologi Bandung Bandung Indonesia Jakarta Indonesia Postdam Germany

From November 2015 to February 2016, seismic swarm activity occurred around Jailolo volcano, a long-dormant and few-studied volcano located on Halmahera Island, North Moluccas, Indonesia. We perform seismic ambient noise tomography method to delineate the sub-surface seismic structure beneath Jailolo volcanic complex. We use the vertical seismogram data from 29 temporary short-period seismic stations of 7G Seismic Network from January to March 2017 observation. The 7G Seismic Network was collaborative research between the Indonesian Agency of Meteorology, Climatology, Geophysics (BMKG), Indonesia, and the German Research Centre for Geoscience (GFZ). We cross-correlated vertical components of pair stations to estimate Green's Rayleigh wave function. More than 350 group velocities were estimated. We measure the dispersion characteristic of Rayleigh wave group velocity by applying the frequency-time analysis (FTAN) technique. We compare Green Function and the dispersion curve by applying different band-pass filters. The Green Function of Rayleigh wave is clearly seen in causal and/or acausal part by applied 0.01-0.5 Hz band-pass filter and then dispersion curve is picked within 2-10 s. The Rayleigh group velocities average is 0.6-0.9 km/s. © Published under licence by IOP Publishing Ltd.

关键词： Bandpass filters

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Combined Deep Learning and Classical Potential Approach for Modeling Diffusion in UiO-66

Combined Deep Learning and Classical Potential Approach for ...

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2023 AIChE Annual Meeting

作者： Achar, Siddarth K. Wardzala, Jacob J. Bernasconi, Leonardo Zhang, Linfeng Johnson, J. Karl Department of Chemical & Petroleum Engineering University of Pittsburgh PittsburghPA15261 United States Computational Modeling & Simulation Program University of Pittsburgh PittsburghPA15260 United States Center for Research Computing Department of Chemistry University of Pittsburgh PittsburghPA15260 United States DP Technology Beijing100080 China AI for Science Institute Beijing100080 China

Modeling of diffusion of adsorbates through porous materials with atomistic molecular dynamics (MD) can be a challenging task if the flexibility of the adsorbent needs to be included. This is because potentials need to be developed that accurately account for the motion of the adsorbent in response to the presence of adsorbate molecules. In this work, we show that it is possible to use accurate machine learning atomistic potentials for metal−organic frameworks in concert with classical potentials for adsorbates to accurately compute diffusivities though a hybrid potential approach. As a proof-of-concept, we have developed an accurate deep learning potential (DP) for UiO-66, a metal− organic framework, and used this DP to perform hybrid potential simulations, modeling diffusion of neon and xenon through the crystal. The adsorbate−adsorbate interactions were modeled with Lennard−Jones (LJ) potentials, the adsorbent−adsorbent interactions were described by the DP, and the adsorbent−adsorbate interactions used LJ cross-interactions. Thus, our hybrid potential allows for adsorbent−adsorbate interactions with classical potentials but models the response of the adsorbent to the presence of the adsorbate through near-DFT accuracy DPs. This hybrid approach does not require refitting the DP for new adsorbates. We calculated self-diffusion coefficients for Ne in UiO-66 from DFT-MD, our hybrid DP/LJ approach, and from two different classical potentials for UiO-66. Our DP/LJ results are in excellent agreement with DFT-MD. We modeled diffusion of Xe in UiO-66 with DP/LJ and a classical potential. Diffusion of Xe in UiO-66 is about a factor of 30 slower than that of Ne, so it is not computationally feasible to compute Xe diffusion with DFT-MD. Our hybrid DP−classical potential approach can be applied to other MOFs and other adsorbates, making it possible to use an accurate DP generated from DFT simulations of an empty adsorbent in concert with existing classical potentials for ads

关键词： Molecular dynamics

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High Pressure Rheology of Gas Hydrate in Multiphase Flow Systems 5th

High Pressure Rheology of Gas Hydrate in Multiphase Flow Sys...

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5th International Conference in Ocean Engineering, ICOE 2019

作者： Pandey, Gaurav Sangwai, Jitendra S. Department of Petroleum Engineering and Earth Sciences University of Petroleum and Energy Studies Dehradun248007 India Gas Hydrate and Flow Assurance Laboratory Petroleum Engineering Program Department of Ocean Engineering Indian Institute of Technology Madras Chennai600036 India Department of Chemical and Biomolecular Engineering National University of Singapore Singapore117585 Singapore

ISBN: (纸本)9789811585050

The measurement of the rheological properties of gas hydrate slurries necessitates the high pressure rheometer that can provide a proper mixing inside the pressure cell during hydrate formation from two multiphase fluids, water and gas. However, the hydrate formation is highly challenging in conventional cup and bob geometry due to its plane surface. To overcome this, the present work focuses on the study of high pressure rheology for hydrate slurries formed from water-heptane (C7H16) system using a high pressure cell in Anton-Paar® (MCR-52) rheometer and a modified Couette geometry which enables the measurement of rheological studies of multiphase hydrate system. It was observed that the hydrate slurries exhibit shear thinning behavior. The present study provides an important information about the rheology of methane hydrate slurries formed from multiphase systems for flow assurance applications. © 2021, Springer Nature Singapore Pte Ltd.

关键词： Gas hydrates

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Hypocenter Determination using a Non-Linear Method in Bali, Lombok, and Nusa Tenggara Regions: Preliminary Result 9

Hypocenter Determination using a Non-Linear Method in Bali, ...

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9th Asian Physics Symposium 2021, APS 2021

作者： Priyambada, F.R. Nugraha, A.D. Supendi, P. Master Program of Earth Sciences Faculty of Earth Sciences and Technology Institut Teknologi Bandung Bandung40132 Indonesia Global Geophysics Research Group Faculty of Mining and Petroleum Engineering Institut Teknologi Bandung Bandung40132 Indonesia Agency for Meteorology Climatology and Geophysics Jakarta10720 Indonesia

Bali, Lombok, and Nusa Tenggara are the region in the south of the Indonesia Archipelago. This region has relatively high seismicity due to subduction activity and faulting. The first step of the tomography study for inferring the geometry structure beneath Bali, Lombok, and Nusa Tenggara is to conduct precise hypocenter location. In this study, we used waveform data from the Indonesian Agency for Meteorology, Climatology, and Geophysics (BMKG), which the study area is between 1120 - 1280 E and 40 - 130 S. Our preliminary results, we have re-picked 7,967 P-wave and 3,254 S-wave arrival times for 933 events in the period from January to March 2019. The non-linear method was conducted using the oct-tree sampling algorithm from the NLLoc program to determine the hypocenter's location. We also compared the results with BMKG catalog data. Our results show better clustering earthquakes with RMS error mostly close to zero and represent the geological structure in this region. The results show a shift in the location of the epicenters between 0.1 km to 1000 km, while for the focus depth between 0.006 - 500 km, with the azimuth shift being dominated to the northeast and southwest. The future and ongoing works, we will conduct a tomography study to imaging 3-D seismic velocity models beneath Bali, Lombok, and Nusa Tenggara regions using the fast-marching method. © Published under licence by IOP Publishing Ltd.

关键词： Tomography

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A study on the main parameters that affects the reliability of fatigue failure in a marine drilling riser 40

A study on the main parameters that affects the reliability ...

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2021 40th International Conference on Ocean, Offshore and Arctic Engineering, OMAE 2021

作者： das Chagas, Bruno Luiz Barbosa Morooka, Celso Kazuyuki Technology and Innovation Department Ocyan SA Macae - RJ Brazil Faculty of Mechanical Engineering University of Campinas Campinas-SP Brazil Graduate Program in Petroleum Science and Engineering University of Campinas

ISBN: (纸本)9780791885147

Advances in subsea exploration in the oceans to discover new petroleum reservoirs and sometimes different kind of minerals at the seabed in ultra deepwater, continuously introduce new challenges in offshore drilling operations. This motivates the development of increasingly safe maritime operations. In offshore petroleum, a marine drilling riser is the pipe that connects a wellhead at the sea bottom to a drillship at the sea surface, as an access to the wellbore. It serves as a guide for the drilling column with the drill bit and conductor to carry cuttings of rock coming from the wellbore drilling and its construction. Drilling riser is constantly exposed to adversity from the environment, such as waves, sea currents and platform motions induced by waves. These elements of the environment are prevailing factors that can cause a riser failure during deepwater drilling operations with undesirable consequences for the environment. In the present work, key parameters that influence the probability of fatigue failure in a marine drilling riser are identified, and a parametric evaluation with those parameters are carried out. Dynamic behavior of a riser is previously calculated and fatigue damage is estimated. Afterwards, the First Order Reliability Method (FORM) is applied to determine the probability of fatigue failure on the riser. Fundamentals of the procedure are described, and results are illustrated through the analysis for a typical riser in deepwater drilling operation. Parametric evaluations are done observing points considered as critical along the riser length, and looking to the sensitivity of key parameters in the process. For this study, the SN curve from API guidelines is applied and accumulated fatigue damage is estimated from simulations of the stress time series and applying the Palmgren-Miner's rule. Finally, the influence of each parameter in the reliability of fatigue failure is verified and discussions given. Copyright © 2021 by ASME

关键词： Reliability

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Influence of Ce3+ doping on the algal inhibiting properties of copper/sepiolite nanofibers

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Environment Protection Engineering 2021年第4期43卷 253-263页

作者： Zhang, C.C. Duan, X. Ding, Y. Srinivasakannan, C. Institute of Power Source and Ecomaterials Science Hebei University of Technology Tianjin300130 China Key Laboratory of Special Functional Materials for Ecological Environment and Information Hebei University of Technology Ministry of Education Tianjin300130 China Chemical Engineering Program The Petroleum Institute P.O. Box 2533 Abu Dhabi United Arab Emirates

Algal inhibiting materials were synthesized by the co-impregnation method. Cerium was taken as an algal inhibiting agent with copper/sepiolite utilized as the carrier. The algal growth inhibition was assessed based on the form of presence and distribution of Cu2+and Ce3+ ions on the surface of sepiolite using X-ray diffraction (XRD) and SEM analysis. The results indicate that at 5 wt. % Cu content, 0.8 wt. % Ce and after heat treatment at 400 °C, the materials exhibit the best algal inhibiting capacity of 83.11%. © 2017 Technical University of Wroclaw. All rights reserved.

关键词： Copper

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Phase Equilibria and Kinetics of Methane Hydrate Formation and Dissociation in Krishna–Godavari Basin Marine Sediments 5th

Phase Equilibria and Kinetics of Methane Hydrate Formation a...

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5th International Conference in Ocean Engineering, ICOE 2019

作者： Bhawangirkar, Dnyaneshwar R. Nair, Vishnu Chandrasekharan Sangwai, Jitendra S. Petroleum Engineering Program Gas Hydrate and Flow Assurance Laboratory Department of Ocean Engineering Indian Institute of Technology Madras Chennai600036 India Department of Chemical Engineering Indian Institute of Technology Bombay Powai Mumbai400076 India

ISBN: (纸本)9789811585050

Understanding the formation and dissociation behavior of methane gas hydrate in marine sediments is one of the important precursors for methane gas production from the hydrate deposits. The phase behavior of gas hydrates is influenced by the presence of sediments, composition of salts and water present in it. Krishna–Godavari (KG) Basin in India is one such reservoir which has a huge potential of methane gas hydrates. Here, we have investigated the phase equilibria, and the kinetics of methane hydrate formation, and dissociation in the presence of pure water, and in aqueous solution of 10 wt% (KG) basin sediment. We observed that the phase equilibrium conditions of methane hydrate in presence of 10 wt% sediment solution got shifted to slightly higher pressures at given temperature as compared to that in the bulk phase. It has also been observed that more number of methane gas molecules are consumed in 10 wt% sediment solution in the initial 30 minutes of time than in the pure water system, revealing the promotion effect of sediment surface. The number of moles of methane gas released during the dissociation of hydrate has found to be lesser in sediment solution than in pure water at any given time after initial 55 min of the start of dissociation. © 2021, Springer Nature Singapore Pte Ltd.

关键词： Kinetics

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Effect evaluation of fluid movement and rock properties for artificial seismic activity on hydrocarbons

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Heliyon 2024年第20期10卷 e39572页

作者： Kanjirakat, Anoop Abughaush, Laith Carvero, Arnel Rabbani, Harris Amani, Mahmood Retnanto, Albertus Department of Aeronautical and Automobile Engineering Manipal Institute of Technology (MIT) Manipal Academy of Higher Education (MAHE) Manipal 576104 India Petroleum Engineering Program Texas A&M University at Qatar Education City Doha Qatar

Despite the effectiveness of seismic stimulation in enhancing oil production from reservoirs, the impact of high-frequency vibrations on oil droplets confined within pore throats has not been adequately investigated. This laboratory-scale experimental study examines the impact of low and high-frequency sinusoidal vibrations in dislodging oil droplets trapped in a specific pore-throat region. Sinusoidal vibrations ranging from 10 to 80 Hz and with maximum displacement amplitudes of 1.2–0.06 mm are applied. By comparing the images captured prior to and after the application of seismic vibrations, the amount of oil recovered is determined. Commercial gasoline and diesel are used as trapped oil samples, and water is used as the injection fluid to bring out the effect of fluid viscosities in seismic dislodgment. While applying vibrations to trapped oil in the pore throat, three different recovery modes are observed: continuous, snap-off, and emulsified. The continuous oil recovery mode is observed in cases with minimal flow resistance through the pore throat, whereas a snap-off or intermittent recovery mode is observed when the flow resistance is high, and the vibration frequencies fall within the midrange of 40–60 Hz. An emulsified oil recovery mode is observed at high vibration frequencies. The amount of recovered oil increases as geometrical restrictions and trapped oil viscosity decrease. Seismic mobilization is observed to be directly proportional to the mobilization velocity and inversely proportional to the entrapped oil viscosity and geometrical restriction factors. © 2024 The Authors

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