The Experts below are selected from a list of 126951 Experts worldwide ranked by ideXlab platform

P K Karlis - One of the best experts on this subject based on the ideXlab platform.

  • thermal alkaline solubilization of waste activated sludge as a pre treatment stage for anaerobic digestion
    Bioresource Technology, 2004
    Co-Authors: A G Vlyssides, P K Karlis
    Abstract:

    Abstract This work studied the hydrolysis kinetics and the solubilization of waste activated sludge under a medium range temperature (50–90 °C) and pH in the alkaline region (8–11), as a pretreatment stage for anaerobic digestion. The hydrolysis rate for the solubilization of volatile suspended solids (VSS) followed a first-order rate. A Linear Polynomial hydrolysis model was derived from the experimental results leading to a satisfactory correlation between the hydrolysis rate coefficient, pH, and temperature. At pH 11 and a temperature of 90 °C the concentration of the VSS was 6.82%, the VSS reduction reached 45% within ten hours and at the same time the soluble COD was 70.000 mg/l and the total efficiency for methane production 0.28 l of CH4 per g of VSS loading.

  • thermal alkaline solubilization of waste activated sludge as a pre treatment stage for anaerobic digestion
    Bioresource Technology, 2004
    Co-Authors: A G Vlyssides, P K Karlis
    Abstract:

    This work studied the hydrolysis kinetics and the solubilization of waste activated sludge under a medium range temperature (50-90 degrees C) and pH in the alkaline region (8-11), as a pretreatment stage for anaerobic digestion. The hydrolysis rate for the solubilization of volatile suspended solids (VSS) followed a first-order rate. A Linear Polynomial hydrolysis model was derived from the experimental results leading to a satisfactory correlation between the hydrolysis rate coefficient, pH, and temperature. At pH 11 and a temperature of 90 degrees C the concentration of the VSS was 6.82%, the VSS reduction reached 45% within ten hours and at the same time the soluble COD was 70.000 mg/l and the total efficiency for methane production 0.28 l of CH4 per g of VSS loading.

Metin Turkay - One of the best experts on this subject based on the ideXlab platform.

  • Optimal estimation of physical properties of the products of an atmospheric distillation column using support vector regression
    Computers & Chemical Engineering, 2020
    Co-Authors: Ahmet Can Serfidan, Firat Uzman, Metin Turkay
    Abstract:

    Abstract Atmospheric distillation column is one of the most important units in an oil refinery where crude oil is fractioned into its more valuable constituents. Almost all of the state-of-the art online equipment has a time lag to complete the physical property analysis in real time due to complexity of the analyses. Therefore, estimation of the physical properties from online plant data with a soft sensor has significant benefits. In this paper, we estimate the physical properties of the hydrocarbon products of an atmospheric distillation column by support vector regression using Linear, Polynomial and Gaussian Radial Basis Function kernels and SVR parameters are optimized by using a variety of algorithms including genetic algorithm, grid search and non-Linear programming. The optimization-based data analytics approach is shown to produce superior results compared to Linear regression, the mean testing error of estimation is improved by 5% with SVR 4.01 °C to 3.8 °C.

A G Vlyssides - One of the best experts on this subject based on the ideXlab platform.

  • thermal alkaline solubilization of waste activated sludge as a pre treatment stage for anaerobic digestion
    Bioresource Technology, 2004
    Co-Authors: A G Vlyssides, P K Karlis
    Abstract:

    Abstract This work studied the hydrolysis kinetics and the solubilization of waste activated sludge under a medium range temperature (50–90 °C) and pH in the alkaline region (8–11), as a pretreatment stage for anaerobic digestion. The hydrolysis rate for the solubilization of volatile suspended solids (VSS) followed a first-order rate. A Linear Polynomial hydrolysis model was derived from the experimental results leading to a satisfactory correlation between the hydrolysis rate coefficient, pH, and temperature. At pH 11 and a temperature of 90 °C the concentration of the VSS was 6.82%, the VSS reduction reached 45% within ten hours and at the same time the soluble COD was 70.000 mg/l and the total efficiency for methane production 0.28 l of CH4 per g of VSS loading.

  • thermal alkaline solubilization of waste activated sludge as a pre treatment stage for anaerobic digestion
    Bioresource Technology, 2004
    Co-Authors: A G Vlyssides, P K Karlis
    Abstract:

    This work studied the hydrolysis kinetics and the solubilization of waste activated sludge under a medium range temperature (50-90 degrees C) and pH in the alkaline region (8-11), as a pretreatment stage for anaerobic digestion. The hydrolysis rate for the solubilization of volatile suspended solids (VSS) followed a first-order rate. A Linear Polynomial hydrolysis model was derived from the experimental results leading to a satisfactory correlation between the hydrolysis rate coefficient, pH, and temperature. At pH 11 and a temperature of 90 degrees C the concentration of the VSS was 6.82%, the VSS reduction reached 45% within ten hours and at the same time the soluble COD was 70.000 mg/l and the total efficiency for methane production 0.28 l of CH4 per g of VSS loading.

B D Kulkarni - One of the best experts on this subject based on the ideXlab platform.

  • development of a soft sensor for a batch distillation column using support vector regression techniques
    Chemical Engineering Research & Design, 2007
    Co-Authors: P Jain, Imran Rahman, B D Kulkarni
    Abstract:

    A support vector regression (SVR)-based model is developed for a batch distillation process in order to estimate the product compositions from temperature measurements. Kernel function such as Linear, Polynomial and RBF are employed for SVR modelling. The original process data was generated by simulating the batch distillation process, varying the initial feed composition and boilup rate from batch to batch. Within each batch reflux ratio was also randomly changed to represent the true dynamics of the batch distillation. The results show the potential of the method for developing softsensor for chemical processes.

Elchanan Mossel - One of the best experts on this subject based on the ideXlab platform.

  • harmonicity and invariance on slices of the boolean cube
    Conference on Computational Complexity, 2016
    Co-Authors: Yuval Filmus, Elchanan Mossel
    Abstract:

    In a recent work with Kindler and Wimmer we proved an invariance principle for the slice for low-influence, low-degree functions. Here we provide an alternative proof for general low-degree functions, with no constraints on the influences. We show that any real-valued function on the slice, whose degree when written as a harmonic multi-Linear Polynomial is [EQUATION], has approximately the same distribution under the slice and cube measure. Our proof is based on a novel decomposition of random increasing paths in the cube in terms of martingales and reverse martingales. While such decompositions have been used in the past for stationary reversible Markov chains, ours decomposition is applied in a non-reversible non-stationary setup. We also provide simple proofs for some known and some new properties of harmonic functions which are crucial for the proof. Finally, we provide independent simple proofs for the known facts that 1) one cannot distinguish between the slice and the cube based on functions of o(n) coordinates and 2) Boolean symmetric functions on the cube cannot be approximated under the uniform measure by functions whose sum of influences is [EQUATION].

  • harmonicity and invariance on slices of the boolean cube
    arXiv: Probability, 2015
    Co-Authors: Yuval Filmus, Elchanan Mossel
    Abstract:

    In a recent work with Kindler and Wimmer we proved an invariance principle for the slice for low-influence, low-degree functions. Here we provide an alternative proof for general low-degree functions, with no constraints on the influences. We show that any real-valued function on the slice, whose degree when written as a harmonic multi-Linear Polynomial is $o(\sqrt{n})$, has approximately the same distribution under the slice and cube measure. Our proof is based on a novel decomposition of random increasing paths in the cube in terms of martingales and reverse martingales. While such decompositions have been used in the past for stationary reversible Markov chains, ours decomposition is applied in a non-reversible non-stationary setup. We also provide simple proofs for some known and some new properties of harmonic functions which are crucial for the proof. Finally, we provide independent simple proofs for the facts that 1) one cannot distinguish between the slice and the cube based on functions of $o(n)$ coordinates and 2) Boolean symmetric functions on the cube cannot be approximated under the uniform measure by functions whose sum of influences is $o(\sqrt{n})$.