New Approaches for Theoretical Estimation of Mass Transfer Parameters in Both Gas-Liquid and Slurry Bubble Columns

Optical physic

Investigation of the radial effect on the transition velocities in a bubble column based on the modified Shannon entropy

AbstractA new parameter for flow regime identification in a bubble column based on the calculation of the Shannon entropy (SE) from different parts of the signal was developed. The bubble column (0.15m in ID) was equipped with a perforated plate distributor (14 holes, Ø 4×10−3m) and operated with an air-deionized water system at ambient conditions. The newly introduced dimensionless ratio of minimum SE to maximum SE was capable of identifying the main transition velocities Utrans at three different dimensionless radial positions (r/R): 0.0 (core), 0.63 (inversion point of axial liquid velocity) and 0.88 (annulus).In the column’s core the new dimensionless SE ratio identified successfully three Utrans values at 0.034, 0.089 and 0.134m/s. They marked the end of the gas maldistribution regime, the onset and the end of the churn-turbulent flow regime, respectively. Three Utrans values (at 0.045, 0.089 and 0.124m/s) were also identified in the annulus. However, the second Utrans value identified the boundary between the first and second transition sub-regimes. The third Utrans value distinguished the onset of the churn-turbulent flow regime. It was found that in the core both the transition and churn-turbulent flow regimes started earlier.At r/R=0.63 the end of the gas maldistribution regime was shifted to a somewhat higher Utrans value (0.067m/s). The second transition sub-regime began at 0.101m/s, whereas the onset of the churn-turbulent regime occurred at 0.124m/s

METHODS AND APPARATUS FOR INTENT AND CONTEXT-BASED AD-HOC DATA DRIVEN REPORTING AND VISUALIZATION

Existing executive events, investment planning sessions, regular checkups, service reviews, etc. are mainly based on static content such as templates, PDF files and PPT presentations. However, these templates have static dashboard and predefined scenarios that cannot be changed/altered during the presentation and lack the ability to visually-represent relevant ad-hoc content. As such, presented herein are dynamic (ad-hoc) and context-based visualization systems that are more intuitive than conventional arrangements. The techniques presented herein may, for example, facilitate a more natural decision making process by providing content that can dynamically change based, for example, on the current context, such as important in-depth questions supporting a decision making process, etc. In one example, a user may ask a follow up question and the system is configured to store the context and provide a recursive answer. The system may offer the next best question, based on an embedded convolutional sequence. The techniques presented herein may also use generative models and graph classifiers to convert data into a visual representation

Flow Regime Identification in a Bubble Column Via Nuclear Gauge Densitometry and Chaos Analysis

The Bubble Column Performance Can Change Significantly as a Result of Flow Regime Change. Since Reactor Volume Productivity, Mass and Heat Transfer as Well as Mixing Are Affected by the Prevailing Flow Regime, It is Very Important to Know How to Identify It. in This Work, Flow Regime Identification Was Performed on the Basis of the Kolmogorov Entropy (KE) Algorithm Applied to Nuclear Gauge Densitometry Data. in Addition, the Average Cycle Time Was Used for Validation of the Results. Three Transition Velocities Were Identified that Delineated the Boundaries of the Three Main Hydrodynamic Regimes. the First Two Transition Points Were Also Confirmed by the Information Entropy Concept. the Increasing KE Trend in the Bubbly Flow Regime and the Decreasing KE Trend in the Churn-Turbulent Regime Were Predicted Successfully by Means of New Semi-Theoretical Models. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

Flow Regime Identification in a Bubble Column based on Both Statistical and Chaotic Parameters Applied to Computed Tomography Data

The Kolmogorov Entropy (KE) Algorithm Was Applied Successfully to Single Source Γ-Ray Computed Tomography (CT) Data Measured in a 0.162 M ID Bubble Column Equipped with a Perforated Plate Distributor (163 Holes · Ø 1.32 Mm). Dried Air Was Used as the Gas Phase and Therminol LT (ΡL = 886 Kg M-3, ΜL = 0.88 · 10-3 Pa S, Σ = 17 · 10-3 N M-1) Was Used as a Liquid Phase. Three Different Pressures, P, of 0.1, 0.4, and 1.0 MPa Were Examined. at Each Pressure the Superficial Gas Velocity, UG, Was Increased Stepwise by Steps of 0.01 Ms-1 Up to 0.2 Ms-1. the Average Absolute Deviation (AAD) Was Also Used as a Robust Statistical Criterion for Regime Transition. at All Three Pressures, based on the Sudden Changes in Both the AAD and KE Values, the Boundaries of the Following Five Regimes Were Identified: Dispersed Bubble Regime, First and Second Transition Regimes, Coalesced Bubble Regime Consisting of Four Regions (Called 4-Region Flow), and Coalesced Bubble Regime Consisting of Three Regions (Called 3-Region Flow). the Existence of These Regimes Has Already Been Documented. as the Pressure Increases, the Transition Velocity between the Dispersed Bubble and First Transition Regimes and the Transition Velocity between Coalesced Bubble (4-Region Flow) and Coalesced Bubble (3-Region Flow) Regimes Shift to Higher UG Values. on the Other Hand, at P = 0.4 MPa the Second Transition Regime Starts Earlier. in Addition, P = 1 MPa the Transition to Coalesced Bubble (4-Region Flow) is Delayed. © 2006 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim

Prediction of the Kolmogorov Entropy Derived from Computed Tomography Data in a Bubble Column Operated under the Transition Regime and Ambient Pressure

The Kolmogorov Entropy (KE) Algorithm Was Successfully Applied to Single Source Γ-Ray Computed Tomography (CT) Data Measured by Three Scintillation Detectors in a 0.162 M-ID Bubble Column Equipped with a Perforated Plate Distributor (163 Holes X ∅ 1.32. 10-3 M). the Aerated Liquid Height Was Set at 1.8 M. Dried Air Was Used as a Gas Phase, While Therminol LT (PL = 886 Kg M-3, ΜL = 0.88.10-3 Pa S, Σ = 17.10-3 N M-1) Was Used as a Liquid Phase. at Ambient Pressure, the Superficial Gas Velocity, ΜG, Was Increased Stepwise with an Increment of 0.01 M S-1 Up to 0.2 M S-1. based on the Sudden Changes in the KE Values, the Boundaries of the Following Five Regimes Were Successfully Identified: Dispersed Bubble Regime (ΜG \u3c 0.02 M S-1), First Transition Regime (0.02 ≤ UG \u3c 0.08 M S-1), Second Transition Regime (0.08 ≤ UG \u3c 0.1 M S-1), Coalesced Bubble Regime Consisting of Four Regions (Called 4-Region Flow; 0.1 ≤ UG \u3c 0.12 M S-1), and Coalesced Bubble Regime Consisting of Three Regions (Called 3-Region Flow; UG \u3e 0.12 M S-1). the KE Values Derived from Three Scintillation Detectors in the First Transition Regime Were Successfully Correlated to Both Bubble Frequency and Bubble Impact. the Latter Was Found to Be Inversely Proportional to the Bubble Froude Number. the KE Model Implies that the Bubble Size in This Particular Flow Regime is a Weak Function of the Orifice Reynolds Number (Db = 7.1.10-3 Re0-0.05). © 2007 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim

VIRTUALIZED INTELLIGENT HONEYPOT AGENT

A honeypot system is described that can expand to any attack surface as it learns and grows with the changing device landscape. The system also takes into account the human elements that originated the attack. By using adversarial training mechanisms, the system may be quickly trained to become a doppelganger and attract attacks. Moreover, a unique quantum cognitive framework provides a robust adaptivity to ever-changing attacker strategies. Virtualized intelligent honeypot agents may be introduced into the network, device, or server, to connect and share knowledge to facilitate federated learning for similar type of agents. The agents may also be operated in multitasking for many similar types of devices, users, applications, and the like

Low awareness of transient ischemic attacks and risk factors of stroke in a Swiss urban community

Background and purpose: Time delays from stroke onset to arrival at the hospital are the main obstacles for widespread use of thrombolysis. In order to decrease the delays, educational campaigns try to inform the general public how to act optimally in case of stroke. To determine the content of such a campaign, we assessed the stroke knowledge in our population. Methods: The stroke knowledge was studied by means of a closed-ended questionnaire. 422 randomly chosen inhabitants of Bern, Switzerland, were interviewed. Results: The knowledge of stroke warning signs (WS) was classified as good in 64.7%. A good knowledge of stroke risk factors (RF) was noted in 6.4%. 4.2% knew both the WS and the RF of stroke indicating a very good global knowledge of stroke. Only 8.3% recognized TIA as symptoms of stroke resolving within 24hours, and only 2.8% identified TIA as a disease requiring immediate medical help. In multivariate analysis being a woman, advancing age, and having an afflicted relative were associated with a good knowledge of WS (p=0.048, p<0.001 and p=0.043). Good knowledge of RF was related to university education (p<0.001). The good knowledge of TIA did not depend on age, sex, level of education or having an afflicted relative. Conclusions: The study brings to light relevant deficits of stroke knowledge in our population. A small number of participants could recognize TIA as stroke related symptoms resolving completely within 24hours. Only a third of the surveyed persons would seek immediate medical help in case of TIA. The information obtained will be used in the development of future educational campaign

Synthesis and characterization of photoactive amorphous molecular and polymeric pyridinium materials

Pyridinium materials both molecular and polymeric are interesting class of multifunctional electrolytes and polyelectrolytes, which exhibit liquid-crystalline and light-emitting properties. Moreover, their properties could be easily tuned simply by modifying the chemical structures of counterions. In this dissertation, we described the preparation and analysis of new ionic molecular materials based on bis(pyridinium salt)s and a new class of poly(pyridinium salt)s with various heterocyclic moieties in their backbones with various organic counterions. They were prepared by either ring-transmutation reaction or by metathesis reaction. Their chemical structures were confirmed by FTIR, 1H and 13C NMR spectroscopy and elemental analysis. They had excellent thermal stability comparable to many high performance polymers and high glass transition temperatures. These materials had good solubility in common organic solvents and, therefore, they could be efficiently processed into thin films and fibers. In some cases, the solubility of poly(pyridinium salt)s in organic solvents exceeded critical concentrations above which they exhibited lyotropic iv liquid-crystalline phases as determined with POM studies. The light-emission properties of these materials were examined by spectrofluorometry in both solution and film states. Their quantum yields were also assessed. The morphologies of films and hand-drawn fibers from both molecular and polymeric materials were thoroughly studied with POM, XRD, SEM and TEM techniques. These materials could be good candidates for high performance applications in the field of optoelectronics