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Tendinopathy is a multi-faceted pathology characterized by alterations in tendon microstructure, cellularity and collagen composition. Challenged by the possibility of regenerating ...pathological or ruptured tendons, the healing mechanisms of this tissue have been widely researched over the past decades. However, so far, most of the cellular players and processes influencing tendon repair remain unknown, which emphasizes the need for developing relevant in vitro models enabling to study the complex multicellular crosstalk occurring in tendon microenvironments. In this review, we critically discuss the insights on the interaction between tenocytes and the other tendon resident cells that have been devised through different types of existing in vitro models. Building on the generated knowledge, we stress the need for advanced models able to mimic the hierarchical architecture, cellularity and physiological signaling of tendon niche under dynamic culture conditions, along with the recreation of the integrated gradients of its tissue interfaces. In a forward-looking vision of the field, we discuss how the convergence of multiple bioengineering technologies can be leveraged as potential platforms to develop the next generation of relevant in vitro models that can contribute for a deeper fundamental knowledge to develop more effective treatments.
This paper is concerned with calculating the electromagnetic forces in the windings of distribution transformers with different shapes of coils. The electromagnetic forces as well as the magnetic ...flux density and their distribution were analyzed and calculated using Finite Element Method (FEM). The Finite Element models of the distribution transformers with non-linear magnetic characteristics for the iron core are built using FEM software "ANSYS". In this paper, the static analysis method is based on two-dimensional models, and these models have been solved by using the formula for the magnetic vector voltage (A). Three types of three-phase distribution transformers were adopted, each with a capacity of 250 kVA and a voltage ratio is 11 / 0.416 kV. These types of transformers with different shapes of coils are stack core transformer with oval coil, wound core transformer with rectangular coil, and stack core transformer with cylindrical coil. The results obtained from the FEM analysis agreed with the design calculations which depend on the conventional design formulas. The most important contributions of this study are to building two-dimensional models for different types of distribution transformers. Calculating electromagnetic forces in transformers winding during short circuit conditions in different coil shapes. Studding the effect of the shape of the coils on the calculation of the electromagnetic forces in them. This work can save time, effort, and cost for transformer manufacturers in calculating the electromagnetic forces, also using this model for the virtual test leads to avoid the risk, and efforts spent to do the real short-circuit test on the transformer before manufacturing.
The utilization of hydraulic fracturing for the extraction of natural gas hydrates in maritime environments has been relatively underexplored in the existing literature. This study introduces a novel ...approach by employing a fully implicit integration method to construct a two-dimensional temperature distribution model of the wellbore. The model considers critical parameters such as fracturing fluid time, initial temperature, and fracturing fluid displacement to forecast the temperature data of the wellbore and its surrounding environments throughout the entire fracturing process. The investigation reveals that the initial temperature of the fracturing liquid and the duration of the fracturing process exert a substantial influence on the wellbore temperature, whereas the impact of fracturing fluid displacement is found to be minimal. Furthermore, a comparative analysis between the results derived from the proposed model and those obtained from traditional steady-state formulas substantiates the accuracy and efficacy of the developed model. This study significantly advances our comprehension of temperature dynamics within wellbores during hydraulic fracturing operations in maritime environments, thereby offering valuable insights for future endeavors in natural gas hydrate extraction.
This paper is concerned with calculating the electromagnetic forces in the windings of distribution transformers with different shapes of coils. The electromagnetic forces as well as the magnetic ...flux density and their distribution were analyzed and calculated using Finite Element Method (FEM). The Finite Element models of the distribution transformers with non-linear magnetic characteristics for the iron core are built using FEM software "ANSYS". In this paper, the static analysis method is based on two-dimensional models, and these models have been solved by using the formula for the magnetic vector voltage (A). Three types of three-phase distribution transformers were adopted, each with a capacity of 250 kVA and a voltage ratio is 11/0.416 kV. These types of transformers with different shapes of coils are stack core transformer with oval coil, wound core transformer with rectangular coil, and stack core transformer with cylindrical coil. The results obtained from the FEM analysis agreed with the design calculations which depend on the conventional design formulas. The most important contributions of this study are to building two-dimensional models for different types of distribution transformers. Calculating electromagnetic forces in transformers winding during short circuit conditions in different coil shapes. Studding the effect of the shape of the coils on the calculation of the electromagnetic forces in them. This work can save time, effort, and cost for transformer manufacturers in calculating the electromagnetic forces, also using this model for the virtual test leads to avoid the risk, and efforts spent to do the real short-circuit test.
On Stabilization of 2D Roesser Models Bachelier, Olivier; Yeganefar, Nima; Mehdi, Driss ...
IEEE transactions on automatic control,
05/2017, Volume:
62, Issue:
5
Journal Article
Peer reviewed
This note is devoted to the stabilization of 2D Roesser models which are discrete, continuous, or mixed continuous-discrete. A recent linear matrix inequalities (LMIs) necessary and sufficient ...condition for stability of such models is used to derive a quasi non conservative technique for state feedback stabilization.
AbstractModelling floods in urban areas generally requires the modelling of both surface and subsurface flows, along with the exchange discharges between these flows. These latter exchanges are ...studied on an experimental facility at the Ujigawa Open Laboratory of Kyoto University representing a typical urban drainage system with a single street connected through inlets to a drainage pipe located underneath. An exchange model is developed for the cases in which exchange flows are pressurized, applying a head balance between the surface and subsurface layers and using common head loss formulae. Results of the exchange model agree with experimental measurements and show that, for this experimental setup, the exchanges cannot be modelled by fitting a simple and commonly used orifice-type equation. A hydrodynamic model coupling the one-dimensional (1D) and two-dimensional (2D) shallow water equations for, respectively, the pipe and the street flows and including the analytical exchange model is used to simulate the experimental flows. The numerical model can simulate the global characteristics of both street and pipe flows but shows some discrepancies concerning local perturbations of street flow because of the exchange processes.
Floods greatly impact human settlements in flood risk areas, such as floodplains and coastal lowlands, following heavy rainfall. The Alto Guadalentin valley, an orogenic tectonic depression, ...experiences extreme flash floods and land subsidence due to groundwater withdrawal, rendering it one of Europe's fastest subsiding regions. In this study, we compared two 2D flood event models representing different land subsidence scenarios for 1992 and 2016. To determine the flooded area and water depth variations due to land subsidence, the Hydrologic Engineering Centre River Analysis System 2D (HEC-RAS 2D) model was used to simulate flood inundation by the Alto Guadalentin River and its tributaries. Synthetic aperture radar (SAR) satellite (ERS, ENVISAT, and Cosmo-SkyMED) images were employed, along with the interferometric SAR (InSAR) technique, to calculate the magnitude and spatial distribution of land subsidence. By analysing the accumulated subsidence distributions obtained from InSAR, the original topography of the valley in 1992 and 2016 was reconstructed. These digital surface models (DSMs) were then used to generate 2D hydraulic models, simulating flood scenarios in the unsteady mode. The results demonstrated significant changes in the water surface elevation over the 14-year period, with a 2.04 km2 increase in areas with water depths exceeding 0.7 m. These findings were utilized to create a flood risk map and assess the economic flood risk. The data highlight the crucial role of land subsidence in determining the inundation risk in the Alto Guadalentin valley, providing valuable insights for emergency management and civil protection against future potential flooding events.
Intellectual disability (ID) is characterized by deficits in conceptual, social and practical domains. ID can be caused by both genetic defects and environmental factors and is extremely ...heterogeneous, which complicates the diagnosis as well as the deciphering of the underlying pathways. Multiple scientific breakthroughs during the past decades have enabled the development of novel ID models. The advent of induced pluripotent stem cells (iPSCs) enables the study of patient-derived human neurons in 2D or in 3D organoids during development. Gene-editing tools, such as CRISPR/Cas9, provide isogenic controls and opportunities to design personalized gene therapies. In practice this has contributed significantly to the understanding of ID and opened doors to identify novel therapeutic targets. Despite these advances, a number of areas of improvement remain for which novel technologies might entail a solution in the near future. The purpose of this review is to provide an overview of the existing literature on scientific breakthroughs that have been advancing the way ID can be studied in the human brain. The here described human brain models for ID have the potential to accelerate the identification of underlying pathophysiological mechanisms and the development of therapies.
Injection molding is a multiphase process that requires accurate simulation of the filling phase. This is a key element in predicting the complete injection molding cycle. The filling phase presents ...a complex set of challenges, including migrating melt fronts, multi-phase flow, non-Newtonian fluid dynamics, and intertwined heat transfer. Evolving from 1D to 2D, 2.5D, and 3D techniques, filling simulation research has adapted to capture the intricacies of injection-molded parts. However, the need for accuracy in the characterization of the rheological properties of polymers during filling is still of paramount importance. In order to systematically categorize the numerical methods used to simulate the filling phase of injection molding, this review paper provides a comprehensive summary. Particular emphasis is given to the complex interaction of multiple geometric parameters that significantly influence the dynamic evolution of the filling process. In addition, a spectrum of rheological models is thoroughly and exhaustively explored in the manuscript. These models serve as basic mathematical constructs to help describe the complex viscous behavior of polymers during the filling phase. These models cover a spectrum of complexity and include widely recognized formulations such as the Power-Law, second-order, Herschel–Bulkley, Carreau, Bird–Carreau, and Cross models. The paper presents their implementation to include the temperature-dependent influence on viscosity. In this context, the extensions of these models are explained in detail. These extensions are designed to take into account the dynamic viscosity changes caused by the different thermal conditions during the filling process. An important contribution of this study is the systematic classification of these models. This categorization encompasses both academic research and practical integration into commercial software frameworks. In addition to the theoretical importance of these models, their practical value in overcoming challenges in the field of injection molding is emphasized. By systematically outlining these models within a structured framework, this classification promotes a comprehensive understanding of their intrinsic characteristics and relevance in different scenarios.
Rett syndrome (RTT) is a neurodevelopmental disorder caused by mutations in the gene encoding the methyl-CpG-binding protein 2 (MeCP2). Among many different roles, MeCP2 has a high phenotypic impact ...during the different stages of brain development. Thus, it is essential to intensively investigate the function of MeCP2, and its regulated targets, to better understand the mechanisms of the disease and inspire the development of possible therapeutic strategies. Several animal models have greatly contributed to these studies, but more recently human pluripotent stem cells (hPSCs) have been providing a promising alternative for the study of RTT. The rapid evolution in the field of hPSC culture allowed first the development of 2D-based neuronal differentiation protocols, and more recently the generation of 3D human brain organoid models, a more complex approach that better recapitulates human neurodevelopment in vitro. Modeling RTT using these culture platforms, either with patient-specific human induced pluripotent stem cells (hiPSCs) or genetically-modified hPSCs, has certainly contributed to a better understanding of the onset of RTT and the disease phenotype, ultimately allowing the development of high throughput drugs screening tests for potential clinical translation. In this review, we first provide a brief summary of the main neurological features of RTT and the impact of MeCP2 mutations in the neuropathophysiology of this disease. Then, we provide a thorough revision of the more recent advances and future prospects of RTT modeling with human neural cells derived from hPSCs, obtained using both 2D and organoids culture systems, and its contribution for the current and future clinical trials for RTT.
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