scholarly journals MODELAGEM DO COMPORTAMENTO LÍQUIDO-VAPOR EM EQUILÍBRIO ISOBÁRICO PARA A MISTURA HEXAMETILDISILOXANO + ACETATO DE SEC-BUTILA

e-xacta ◽  
2019 ◽  
Vol 12 (1) ◽  
pp. 21
Author(s):  
Plínio Ribeiro Rodrigues ◽  
Jéssica Magalhães Neves Nunes
Keyword(s):  
Experimental Data ◽  
Binary System ◽  
Butyl Acetate ◽  
System Modeling ◽  
Equilibrium Composition ◽  
Thermodynamic System ◽  
State Equation ◽  
High Accuracy ◽  
Actual Behavior ◽  
Average Accuracy

O hexametildisiloxano (HMDSO) e o acetato de sec-butila (ACSB) são compostos orgânicos utilizados em diversas aplicações tecnológicas, dentre elas a síntese química de vários produtos de interesse farmacêutico. No presente trabalho, as composições da mistura dos compostos em equilíbrio foram determinadas por meio do método Bolha P, calculado pela equação de estado cúbica com parâmetros de Peng-Robinson para a pressão de 101,3 kPa. Os erros médios percentuais entre os dados calculados e os valores experimentais também foram determinados, o que permitiu mostrar a precisão do modelo estudado em simular o sistema termodinâmico. Dessa maneira, o modelo mostrou-se útil para o cálculo da composição do equilíbrio do sistema binário avaliado, refletindo o comportamento real da mistura com precisão média de 90,57%, sendo, portanto, adequado a aplicações tecnológicas que exijam exatidão relativamente elevada e servindo de base para estudos futuros de modelagem do sistema HMDSO + ACSB. AbstractHexamethyldisiloxane (HMDSO) and sec-butyl acetate (ACSB) are organic compounds used in various technological applications, such as the chemical synthesis of various products of pharmaceutical interest. In the present work, mixture compositions of the compounds in equilibrium were determined by the Bubble P method, calculated by the cubic state equation with Peng-Robinson parameters for the pressure of 101.3 kPa. Mean percentage errors between the calculated and the experimental data were also determined, which allowed to indicate the precision of the model studied for the thermodynamic system modeling. In this way, the model proved to be useful for calculating the equilibrium composition of the evaluated binary system, reflecting the actual behavior of the mixture with an average accuracy of 90.57%; and is therefore suitable for technological applications that require relatively high accuracy and serving as basis for HMDSO + ACSB system future modeling studies.

scholarly journals An Inverse Problem Involving a Viscous Eikonal Equation with Applications in Electrophysiology

2021 ◽  
Author(s):  
Karl Kunisch ◽  
Philip Trautmann
Keyword(s):  
Inverse Problem ◽  
Least Squares ◽  
Eikonal Equation ◽  
State Equation ◽  
High Accuracy ◽  
Well Posedness ◽  
Numerical Examples ◽  
Marquardt Method ◽  
Math Biol ◽  
Levenberg Marquardt

AbstractIn this work we discuss the reconstruction of cardiac activation instants based on a viscous Eikonal equation from boundary observations. The problem is formulated as a least squares problem and solved by a projected version of the Levenberg–Marquardt method. Moreover, we analyze the well-posedness of the state equation and derive the gradient of the least squares functional with respect to the activation instants. In the numerical examples we also conduct an experiment in which the location of the activation sites and the activation instants are reconstructed jointly based on an adapted version of the shape gradient method from (J. Math. Biol. 79, 2033–2068, 2019). We are able to reconstruct the activation instants as well as the locations of the activations with high accuracy relative to the noise level.

scholarly journals High-Accuracy PVT Relationships for Compressed Fluids and Their Application to BET-like Modelling of CO2 and CH4 Adsorption

2007 ◽  
Vol 25 (8) ◽  
pp. 543-559 ◽  
Author(s):  
Janina Milewska-Duda ◽  
Jan Tadeusz Duda
Keyword(s):  
State Equation ◽  
High Accuracy ◽  
Theoretical Description ◽  
Theoretical Modelling ◽  
Hard Sphere Model ◽  
Cohesion Energy ◽  
Critical Temperatures ◽  
Compression Factor ◽  
Energy Relationships ◽  
Factor Data

This paper presents a set of high-accuracy formulae enabling the evaluation of the compression factor, activity and cohesion energy of fluids at near-critical and super-critical temperatures, with reduced molar volumes ranging from 0.4. Such data are necessary in BET-like theoretical modelling of adsorption process. The proposed fluid state equation (PVT relationship) combines a theoretical description of the fluid entropy (based on a hard-sphere model) with cohesion energy relationships obtained via high-accuracy approximations of universal compression factor data and vapour-liquid equilibria. The resultant relationships are incorporated into a BET-like description of adsorption in materials of irregular microporous structure (LBET model). The set of formulae gathered together in this paper allows the possible effective calculation of adsorption isotherms at near- and super-critical temperatures relative to the pore structures. A multi-variant fitting of the LBET model to the empirical data is proposed to detect active constraints for multilayer adsorption and, hence, to obtain information on the structure of the pores. Application of the formulae to the analysis of methane and carbon dioxide adsorption onto an active carbon is discussed.

The Revised Universal Slope Method to Predict the Low-Cycle Fatigue Lives of Elbow and Tee Pipes

2017 ◽  
Vol 139 (5) ◽  
Author(s):  
Hiun Nagamori ◽  
Koji Takahashi
Keyword(s):  
Experimental Data ◽  
Internal Pressure ◽  
Low Cycle Fatigue ◽  
Experimental Studies ◽  
High Accuracy ◽  
Universal Method ◽  
Cycle Fatigue ◽  
Element Analysis ◽  
Slope Method ◽  
Stress States

The stress states of elbow and tee pipes are complex and different from those of straight pipes. The low-cycle fatigue lives of elbows and tees cannot be predicted by Manson's universal slope method; however, a revised universal method proposed by Takahashi et al. was able to predict with high accuracy the low-cycle fatigue lives of elbows under combined cyclic bending and internal pressure. The objective of this study was to confirm the validity of the revised universal slope method for the prediction of low-cycle fatigue behaviors of elbows and tees of various shapes and dimensions under conditions of in-plane bending and internal pressure. Finite element analysis (FEA) was carried out to simulate the low-cycle fatigue behaviors observed in previous experimental studies of elbows and tees. The low-cycle fatigue behaviors, such as the area of crack initiation, the direction of crack growth, and the fatigue lives, obtained by the analysis were compared with previously obtained experimental data. Based on this comparison, the revised universal slope method was found to accurately predict the low-cycle fatigue behaviors of elbows and tees under internal pressure conditions regardless of differences in shape and dimensions.

scholarly journals PENDETEKSIAN OBJEK ROKOK PADA VIDEO BERBASIS PENGOLAHAN CITRA DENGAN MENGGUNAKAN METODE HAAR CASCADE CLASSIFIER

2018 ◽  
Vol 1 (3) ◽  
pp. 92
Author(s):  
Kadek Oki Sanjaya ◽  
Gede Indrawan ◽  
Kadek Yota Ernanda Aryanto
Keyword(s):  
Image Processing ◽  
Detection System ◽  
High Accuracy ◽  
Special Study ◽  
Cascade Classifier ◽  
Integral Image ◽  
Main Method ◽  
Average Accuracy ◽  
Haar Features ◽  
Haar Cascade

Object detection is a topic widely studied by the scientists as a special study in image processing. Although applications of this topic have been implemented, but basically this technology is not yet mature, futher research is needed to developed to obtain the desired result. The aim of the present study is to detect cigarette objects on video by using the Viola Jones method (Haar Cascade Classifier). This method known to have speed and high accuracy because of combining some concept (Haar features, integral image, Adaboost, and Cascade Classifier) to be a main method to detect objects. In this research, detection testing of cigarettes object is in samples of video with the resolution 160x120 pixels, 320x240 pixels, 640x480 pixels under condition of on 1 cigarette object and condition 2 cigarettes object. The result of this research indicated that percentage of average accuracy highest 93.3% at condition 1 cigarette object and 86,7% in the condition 2 cigarette object that was detected on the video with resolution 640x480 pixels, while the percentage of accuracy lowest 90% at condition 1cigarette object, and 81,7% at the condition 2 cigarette objects, detected on the video with the lowest resolution 160x120 pixels. The percentage of average errors at detection cigarettes object was inversely with percentage of accuracy. So that the detection system is able to better recognize the object of the cigarette, then the number of samples in the database needs to be improved and able to represent various types of cigarettes under various conditions and can be added new parameters related to cigarette object

Solubility of the Ketoconazole (an Antifungal Drug) in Supercritical Carbon Dioxide and Menthol as a Cosolvent (Ternary System): Experimental Data and Empirical Correlations

2021 ◽  
Author(s):  
Gholamhossein Sodeifian ◽  
Seyed Ali Sajadian ◽  
Fariba Razmimanesh ◽  
Seyed Mojtaba Hazaveie
Keyword(s):  
Experimental Data ◽  
Carbon Dioxide ◽  
Binary System ◽  
Supercritical Carbon Dioxide ◽  
Ternary System ◽  
Drug Solubility ◽  
Analysis Method ◽  
Empirical Correlations ◽  
Semiempirical Models ◽  
Supercritical Carbon

Abstract One of the main steps in choosing the drug nanoparticle production processes by supercritical carbon dioxide (SC-CO2) is determining the solubility of the solid solute. For this purpose, the solubility of Ketoconazole (KTZ) in the SC-CO2, binary system, as well as in the SC-CO2-menthol (cosolvent), ternary system, was measured at 308–338 K and 12–30 MPa using the static analysis method. The KTZ solubility in the SC-CO2 ranged between 1.70×10− 6 and 8.02×10− 4, while drug solubility in the SC-CO2 with cosolvent varied from 2.7×10− 5 to 1.96×10− 4. This difference indicated the significant effect of menthol cosolvent on KTZ solubility in the SC-CO2. Moreover, KTZ solubilities in the two systems were correlated by several empirical and semiempirical models. Among them, Sodeifian et al., Bian et al., MST, and Bartle et al. models can more accurately correlate experimental data for the binary system than other used models. Also, the Sodeifian and Sajadian model well fitted the solubility data of the ternary system with AARD,%= 6.45, Radj= 0.995.

scholarly journals Scalar isoscalar form factors for energies above 1 GeV

2019 ◽  
Vol 202 ◽  
pp. 06002
Author(s):  
Stefan Ropertz ◽  
Christoph Hanhart ◽  
Bastian Kubis
Keyword(s):  
Experimental Data ◽  
Scattering Amplitudes ◽  
Form Factors ◽  
Padé Approximants ◽  
High Accuracy ◽  
Data Description ◽  
Pade Approximants ◽  
Low Energies

We present a new parametrization for scattering amplitudes and form factors, which is consistent with high-accuracy dispersive representations at low energies but at the same time allows for a data description of higher mass resonances such as the f0(1500) and f0(2020). The formalism is general and thus can be applied to many decay processes. As an example we discuss the decay of $ \bar {B}_s^0 $ → J/ψππ(KK). From the amplitude fixed in a fit to the experimental data pole positions and residues are extracted via Padé approximants.

scholarly journals Study of Refractive Indices and Its Theories for Mixtures of N, N-Diethylethanamine and Acetates

2020 ◽  
Vol 12 (3) ◽  
pp. 363-370
Author(s):  
P. Tyagi ◽  
K. Kumar ◽  
M. Rani ◽  
N. Sabharwal
Keyword(s):  
Experimental Data ◽  
Methyl Acetate ◽  
Butyl Acetate ◽  
Composition Range ◽  
Polynomial Equation ◽  
Carbon Chain ◽  
Refractive Indices ◽  
Carbon Chain Length ◽  
Propyl Acetate ◽  
Empirical Correlations

This paper reports the refractive indices ( ) of N,N-diethylethanamine + methyl acetate, ethyl acetate, propyl acetate, butyl acetate and pentyl acetate at 298.15 K and at different composition range. The various empirical correlations like Arago-Biot (AB), Gladstone-Dale (GD), Lorentz-Lorenz (L-L) Heller (H), Weiner (W), Newton (Nw) and Erying-John (E-J) were applied to experimental data for estimating theoretical value of refractive indices. For an equimolar mixture, the predicted deviation in refractive index values is consistent well with the experimental data. It has been found that the interactions between amine and different esters decrease when carbon chain length in ester increases. Also refractive indices are affected with change in temperature. To evaluate the standard deviation, RK polynomial equation was fitted to the measured refractive indices data.

Modeling, Experimentation, and Simulation of an Air-Over-Hydraulic Brake System

2009 ◽  
Vol 131 (3) ◽  
Author(s):  
Xicheng Xiong ◽  
Jianhua Wei ◽  
Jian Chen
Keyword(s):  
Experimental Data ◽  
System Modeling ◽  
Brake System ◽  
Hydraulic Actuator ◽  
Similar System ◽  
Modeling And Analysis ◽  
Construction Machinery ◽  
Simulation Results ◽  
Mechanical Dynamics ◽  
Development And Validation

This paper deals with the development and validation of an analytical dynamic model of an air-over-hydraulic (AOH) brake system that is widely used on loaders. The AOH system is broken into five simple and cascaded subsystems, pneumatic circuit, air-hydraulic actuator, brake line, wheel cylinder, and disk brake. Pneumatic, hydraulic, and mechanical dynamics are taken care of in each subsystem. The determination of model coefficients is introduced in detail. Many experiments are performed on an experimental setup of the real AOH system on a loader and the experimental data are compared with the simulation results. Preliminary analysis shows that the simulation results are in good agreement with the experimental data. Other researchers in the areas of brake systems in construction machinery would find the model useful for similar system modeling and analysis

Novel Relations for Drainage and Imbibition Relative Permeabilities

1984 ◽  
Vol 24 (03) ◽  
pp. 275-276 ◽  
Author(s):  
Gian Luigi Chierici
Keyword(s):  
Experimental Data ◽  
Numerical Model ◽  
Relative Permeability ◽  
Nonlinear Regression ◽  
Physical Meaning ◽  
Model Simulation ◽  
Actual Behavior ◽  
Gas Oil ◽  
Data Points ◽  
Relative Permeability Curves

Abstract Exponential four- and five-parameter equations are proposed for gas/oil drainage and water/oil imbibition proposed for gas/oil drainage and water/oil imbibition relative permeability curves. These equations match the experimentally determined curves, in particular at and near their initial points and endpoints, better than standard Corey et al. and polynomial approximations. Some of these parameters have a physical meaning; the others can be determined by nonlinear regression on the experimental data points, and can be adjusted to represent pseudorelative permeability curves. The proposed equations are particularly suitable to describe gas percolation in numerical model simulation of percolation in numerical model simulation of dissolved- gas-drive reservoirs. Introduction In computations concerning the behavior of two-phase flow in porous media, the results may depend strongly on the shape of the relative permeability curves used. Algebraic equations are usually employed to reproduce experimentally determined relative permeability curves, or to approximate them when there are no experimental data. Relations proposed by Corey et al., which are based on bundle-of-capillaries model, are usually employed for gas/oil drainage relative permeability curves. The Wyllie and Gardner model, consisting of a bundle of capillaries cut and rejoined along their axis with related entrapment of the wetting phase, was used by Land to obtain the relations usually employed for water/oil imbibition relative permeability curves. As demonstrated elsewhere. these "classical" relations fail to match the actual behavior of the experimentally determined relative permeability curves, in particular at their initial points and endpoints. particular at their initial points and endpoints. Proposed Relations Proposed Relations Gas/Oil Drainage. The following equations have been found to reproduce very accurately the experimentally determined gas/oil drainage relative permeability curves, including their behavior at the initial points and endpoints. kro = exp (-ARLg),.......(1a) krg = exp (BRg-M),.......(1b) where A, B, L, and M are positive numbers, and Sg - SgcRg = 1 - Siw - Sg (2a) with the constraint Sg - Sgc = 0 for S g is less thanSgc..(2b) Eqs. 1a and 1b are four-parameter equations, the parameters being A, L, Sgc, and Siw,. for kro(So), and B, parameters being A, L, Sgc, and Siw,. for kro(So), and B, M, Sgc, and Siw, for krg(Sg). Only Sgc and Siw have a physical meaning; for statistically homogeneous physical meaning; for statistically homogeneous reservoir zones, the average values of Sgc and Siw, can be evaluated by a normalization technique described elsewhere. The values of the empirical coefficients A, L and B, M are determined by nonlinear regression on the sets of experimental data points. If a regression process is applied to Eqs. 1a and 1b, the minimization of the variance may cover up large relative errors in kr, calc/kr, act in the neighborhood of kr = 0. To avoid this, the logarithmic form of Eqs. 1a and 1b, -1n Kro + ARLg...........(3a) and -1n Krg = BRg-M,........ (3b) is used to evaluate the coefficients A, L and B, M. In this case, the variance of the error of the estimate is (4) which ensures a good match with the relative permeability curves also for k, values near to zero. permeability curves also for k, values near to zero. An example of the matching obtained by this procedure is shown in Fig. 1. procedure is shown in Fig. 1. Water/Oil Imbibition. The following equations have been found to reproduce very accurately the experimentally determined relative permeability curves, including their behavior at the initial points and endpoints. K*ro = exp (ARL2),.......(5a) K*rw = exp (-BRw-M)......(5b) where A, B, L, and M are positive numbers, and Sw - SiwRw = 1-Sor-Sw (6) KroK*ro = Kro(Siw).........(7a) andKrwK*rw = .....(7b)Krw(Sor) SPEJ P. 275

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