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Barcelona Basic model (BBM) 1

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Automatic Visual Leakage Detection and Localization from Pipelines in Chemical Process Plants Using Machine Vision Techniques Reiew

Mina Fahimipirehgalin, Emanuel Trunzer, Matthias Odenweller, Birgit Vogel-Heuser

Engineering 2021, Volume 7, Issue 6,   Pages 758-776 doi: 10.1016/j.eng.2020.08.026

Abstract:

Liquid leakage from pipelines is a critical issue in large-scale process plants. Damage in pipelines affects the normal operation of the plant and increases maintenance costs. Furthermore, it causes unsafe and hazardous situations for operators. Therefore, the detection and localization of leakages is a crucial task for maintenance and condition monitoring. Recently, the use of infrared (IR) cameras was found to be a promising approach for leakage detection in large-scale plants. IR cameras can capture leaking liquid if it has a higher (or lower) temperature than its surroundings. In this paper, a method based on IR video data and machine vision techniques is proposed to detect and localize liquid leakages in a chemical process plant. Since the proposed method is a vision-based method and does not consider the physical properties of the leaking liquid, it is applicable for any type of liquid leakage (i.e., water, oil, etc.). In this method, subsequent frames are subtracted and divided into blocks. Then, principle component analysis is performed in each block to extract features from the blocks. All subtracted frames within the blocks are individually transferred to feature vectors, which are used as a basis for classifying the blocks. The k-nearest neighbor algorithm is used to classify the blocks as normal (without leakage) or anomalous (with leakage). Finally, the positions of the leakages are determined in each anomalous block. In order to evaluate the approach, two datasets with two different formats, consisting of video footage of a laboratory demonstrator plant captured by an IR camera, are considered. The results show that the proposed method is a promising approach to detect and localize leakages from pipelines using IR videos. The proposed method has high accuracy and a reasonable detection time for leakage detection. The possibility of extending the proposed method to a real industrial plant and the limitations of this method are discussed at the end.

Keywords： Leakage detection and localization     Image analysis     Image pre-processing     Principle component analysis     k-nearest neighbor classification    

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Coupled solid-fluid FE-analysis of an embankment dam

Michael PERTL, Matthias HOFMANN, Guenter HOFSTETTER

Frontiers of Structural and Civil Engineering 2011, Volume 5, Issue 1,   Pages 53-62 doi: 10.1007/s11709-010-0084-4

Abstract: A coupled solid-fluid FE-model for partially saturated soils, characterized by modeling the soil as a three-phase material consisting of a deformable soil skeleton and the fluid phases water and air, is reviewed briefly. As a constitutive model for the soil skeleton, the well-known Barcelona Basic model (BBM) is employed, which is formulated in terms of net stress and matric suction. For the BBM, a computationally efficient return mapping algorithm is proposed, which only requires the solution of a scalar nonlinear equation at the integration point level. The coupled FE-model is applied to the coupled transient numerical simulation of the water flow and the deformations and stresses in an embankment dam.

Keywords： multi-phase model     unsaturated soil model     Barcelona Basic model (BBM)     return mapping algorithm     embankment dam    

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Progress in the Physisorption Characterization of Nanoporous Gas Storage Materials Review

Cychosz,Matthias Thommes

Engineering 2018, Volume 4, Issue 4,   Pages 559-566 doi: 10.1016/j.eng.2018.06.001

Abstract:

Assessing the adsorption properties of nanoporous materials and determining their structural characterization is critical for progressing the use of such materials for many applications, including gas storage. Gas adsorption can be used for this characterization because it assesses a broad range of pore sizes, from micropore to mesopore. In the past 20 years, key developments have been achieved both in the knowledge of the adsorption and phase behavior of fluids in ordered nanoporous materials and in the creation and advancement of state-of-the-art approaches based on statistical mechanics, such as molecular simulation and density functional theory. Together with high-resolution experimental procedures for the adsorption of subcritical and supercritical fluids, this has led to significant advances in physical adsorption textural characterization. In this short, selective review paper, we discuss a few important and central features of the underlying adsorption mechanisms of fluids in a variety of nanoporous materials with well-defined pore structure. The significance of these features for advancing physical adsorption characterization and gas storage applications is also discussed.

Keywords： Adsorption     Characterization     High-pressure adsorption     Nanoporous materials    

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Continuous size fractionation of magnetic nanoparticles by using simulated moving bed chromatography

Carsten-Rene Arlt, Dominik Brekel, Stefan Neumann, David Rafaja, Matthias Franzreb

Frontiers of Chemical Science and Engineering 2021, Volume 15, Issue 5,   Pages 1346-1355 doi: 10.1007/s11705-021-2040-3

Abstract: The size fractionation of magnetic nanoparticles is a technical problem, which until today can only be solved with great effort. Nevertheless, there is an important demand for nanoparticles with sharp size distributions, for example for medical technology or sensor technology. Using magnetic chromatography, we show a promising method for fractionation of magnetic nanoparticles with respect to their size and/or magnetic properties. This was achieved by passing magnetic nanoparticles through a packed bed of fine steel spheres with which they interact magnetically because single domain ferro-/ferrimagnetic nanoparticles show a spontaneous magnetization. Since the strength of this interaction is related to particle size, the principle is suitable for size fractionation. This concept was transferred into a continuous process in this work using a so-called simulated moving bed chromatography. Applying a suspension of magnetic nanoparticles within a size range from 20 to 120 nm, the process showed a separation sharpness of up to 0.52 with recovery rates of 100%. The continuous feed stream of magnetic nanoparticles could be fractionated with a space-time-yield of up to 5 mg/(L∙min). Due to the easy scalability of continuous chromatography, the process is a promising approach for the efficient fractionation of industrially relevant amounts of magnetic nanoparticles.

Keywords： magnetic chromatography     simulated moving bed chromatography     magnetic nanoparticles     size fractionation    

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Easy access to pharmaceutically relevant heterocycles by catalytic reactions involving

Ximei Zhao, Matthias Rudolph, Abdullah M. Asiri, A. Stephen K. Hashmi

Frontiers of Chemical Science and Engineering 2020, Volume 14, Issue 3,   Pages 317-349 doi: 10.1007/s11705-019-1874-4

Abstract: This review summarizes recent advances in the field of gold-catalyzed synthesis of pharmaceutically relevant aza-heterocycles via generated -imino gold carbene complexes as intermediates.

Keywords： gold     heterocycles     alkynes    

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Towards an integrated modeling of the plasma-solid interface

Bronold, Matthias Pamperin, Markus Becker, Dettlef Loffhagen, Holger Fehske

Frontiers of Chemical Science and Engineering 2019, Volume 13, Issue 2,   Pages 201-237 doi: 10.1007/s11705-019-1793-4

Abstract: Solids facing a plasma are a common situation in many astrophysical systems and laboratory setups. Moreover, many plasma technology applications rely on the control of the plasma-surface interaction, i.e., of the particle, momentum and energy fluxes across the plasma-solid interface. However, presently often a fundamental understanding of them is missing, so most technological applications are being developed via trial and error. The reason is that the physical processes at the interface of a low-temperature plasma and a solid are extremely complex, involving a large number of elementary processes in the plasma, in the solid as well as fluxes across the interface. An accurate theoretical treatment of these processes is very difficult due to the vastly different system properties on both sides of the interface: Quantum versus classical behavior of electrons in the solid and plasma, respectively; as well as the dramatically differing electron densities, length and time scales. Moreover, often the system is far from equilibrium. In the majority of plasma simulations surface processes are either neglected or treated via phenomenological parameters such as sticking coefficients, sputter rates or secondary electron emission coefficients. However, those parameters are known only in some cases and with very limited accuracy. Similarly, while surface physics simulations have often studied the impact of single ions or neutrals, so far, the influence of a plasma medium and correlations between successive impacts have not been taken into account. Such an approach, necessarily neglects the mutual influences between plasma and solid surface and cannot have predictive power. In this paper we discuss in some detail the physical processes of the plasma-solid interface which brings us to the necessity of coupled plasma-solid simulations. We briefly summarize relevant theoretical methods from solid state and surface physics that are suitable to contribute to such an approach and identify four methods. The first are mesoscopic simulations such as kinetic Monte Carlo and molecular dynamics that are able to treat complex processes on large scales but neglect electronic effects. The second are quantum kinetic methods based on the quantum Boltzmann equation that give access to a more accurate treatment of surface processes using simplifying models for the solid. The third approach are simulations of surface process that are based on density functional theory (DFT) and time-dependent DFT. The fourths are nonequilibrium Green functions that able to treat correlation effects in the material and at the interface. The price for the increased quality is a dramatic increase of computational effort and a restriction to short time and length scales. We conclude that, presently, none of the four methods is capable of providing a complete picture of the processes at the interface. Instead, each of them provides complementary information, and we discuss possible combinations.

Keywords： plasma physics     surface science     plasma-surface modeling     DFT     nonequilibrium Green functions    

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Title Author Date Type Operation

Automatic Visual Leakage Detection and Localization from Pipelines in Chemical Process Plants Using Machine Vision Techniques

Mina Fahimipirehgalin, Emanuel Trunzer, Matthias Odenweller, Birgit Vogel-Heuser

Journal Article

Coupled solid-fluid FE-analysis of an embankment dam

Michael PERTL, Matthias HOFMANN, Guenter HOFSTETTER

Journal Article

Progress in the Physisorption Characterization of Nanoporous Gas Storage Materials

Cychosz,Matthias Thommes

Journal Article

Continuous size fractionation of magnetic nanoparticles by using simulated moving bed chromatography

Carsten-Rene Arlt, Dominik Brekel, Stefan Neumann, David Rafaja, Matthias Franzreb

Journal Article

Easy access to pharmaceutically relevant heterocycles by catalytic reactions involving

Ximei Zhao, Matthias Rudolph, Abdullah M. Asiri, A. Stephen K. Hashmi

Journal Article

Towards an integrated modeling of the plasma-solid interface

Bronold, Matthias Pamperin, Markus Becker, Dettlef Loffhagen, Holger Fehske

Journal Article