Liquid diffusivities for the system methanol–toluene

1967 ◽  
Vol 45 (10) ◽  
pp. 1143-1148 ◽  
Author(s):  
L. W. Shemilt ◽  
R. Nagarajan
Keyword(s):  
Atmospheric Pressure ◽  
Driving Force ◽  
Infinite Dilution ◽  
Composition Range ◽  
Empirical Correlations ◽  
Usual Basis ◽  
Nonideal Systems ◽  
Diaphragm Cell ◽  
Semi Empirical ◽  
Porous Diaphragm

Measurements of the liquid diffusivities over the complete range of compositions of the methanol–toluene system at atmospheric pressure and 25°C have been carried out using the magnetically stirred porous diaphragm cell technique. Diffusivities calculated on the usual basis of concentration as driving force have a minimum of 0.80 × 10−5 cm2 s−1 at 0.4 mole fraction methanol. There is a threefold variation of diffusivity over the entire composition range, and the general behavior is similar to analogous nonideal systems. At infinite dilution none of the semi-empirical correlations, based on various models of the liquid state, give values in agreement with experiment.

A Critical Review of NOx Correlations for Gas Turbine Combustors

1975 ◽  
Author(s):  
D. A. Sullivan ◽  
P. A. Mas
Keyword(s):  
Experimental Data ◽  
Data Base ◽  
Gas Turbine ◽  
Critical Review ◽  
Inlet Temperature ◽  
Nox Emissions ◽  
Empirical Correlations ◽  
Gas Turbine Combustors ◽  
Semi Empirical ◽  
Adequate Data

The effect of inlet temperature, pressure, air flowrate and fuel-to-air ratio on NOx emissions from gas turbine combustors has received considerable attention in recent years. A number of semi-empirical and empirical correlations relating these variables to NOx emissions have appeared in the literature. They differ both in fundamental assumptions and in their predictions. In the present work, these simple NOx correlations are compared to each other and to experimental data. A review of existing experimental data shows that an adequate data base does not exist to evaluate properly the various NOx correlations. Recommendations are proposed to resolve this problem in the future.

Predicting pressure piling by semi-empirical correlations

2005 ◽  
Vol 40 (3) ◽  
pp. 282-298 ◽  
Author(s):  
A. Di Benedetto ◽  
E. Salzano ◽  
G. Russo
Keyword(s):  
Empirical Correlations ◽  
Semi Empirical

scholarly journals A STUDY INTO ICE BUILD-UP AND MELTING ON VERTICAL COOLED PIPES

2016 ◽  
Vol 52 (3) ◽  
Author(s):  
Y. Zasiadko ◽  
O. Pylypenko ◽  
A. Forsiuk ◽  
R. Gryshchenko
Keyword(s):  
Thermal Energy ◽  
Experimental Unit ◽  
Ice Thickness ◽  
Ice Melting ◽  
Empirical Correlations ◽  
Time Intervals ◽  
Ice Accumulation ◽  
Time Periods ◽  
Semi Empirical

The use of cold accumulators based on the principle of ice build up on the cooled surfaces during off-peak periods and ice melting during on-peak periods is an effective method of electricity bills reduction. Within comparatively short periods of on-peak demand a noticeable amount of thermal energy related to ice melting is to be released, it becomes clear that not only sizing of ice accumulators based on balance calculations is actual, but also the determination of time periods of ice accumulation becomes critical. This work presents experimental unit for obtaining data on the ice build-up on the vertical cooled pipes and later on to continuously register data on the ice thickness diminishing at the regimes of ice melting when cooling of pipe stops. The data for ice build-up and melting for some regimes have been presented and analyzed. The data form the base for deriving semi-empirical correlations allowing to determine a time intervals necessary to generate of ice layers of a given thickness.

scholarly journals A Comparison Study on Molecular Interaction of an Acidic Organophosphoric Extractant with Substituted Aromatic Hydrocarbon (p-xylene/toluene) at 303.15K

2020 ◽  
Vol 11 (3) ◽  
pp. 10052-10058
Keyword(s):  
Binary Mixtures ◽  
Ultrasonic Velocity ◽  
Aromatic Hydrocarbons ◽  
Molecular Interaction ◽  
Atmospheric Pressure ◽  
Composition Range ◽  
Isentropic Compressibility ◽  
Extraction Process ◽  
Comparison Study ◽  
Intermolecular Free Length

In the present study, the excess molar volume (VE) and the deviations in intermolecular free length (ΔLf), isentropic compressibility (Δβs), acoustic impedance (ΔZ), and ultrasonic velocity (ΔU) were calculated using the experimentally measured values of density (ρ) and ultrasonic velocity (U) of binary mixtures of an acidic organophosphoric extractant (DEHPA) with two substituted aromatic hydrocarbons, i.e., p-xylene and toluene at 303.15K and atmospheric pressure, 0.1MPa over the entire composition range of DEHPA. The results of both binary mixtures have been presented graphically and compared in terms of molecular interaction between unlike molecules of the mixtures, which outcome may be applied in the solvent extraction process.

scholarly journals Soil classification at Muaro Baru beach of Padang City using CPT data

2021 ◽  
Vol 331 ◽  
pp. 03005
Author(s):  
Rina Yuliet ◽  
Mas Mera ◽  
Krismon Hidayat
Keyword(s):  
Soil Classification ◽  
Soil Profiles ◽  
Sieve Analysis ◽  
Penetration Test ◽  
Empirical Correlations ◽  
Cone Penetration ◽  
Geotechnical Parameters ◽  
Semi Empirical ◽  
Soil Behaviour ◽  
Behaviour Type

Many semi-empiric correlations have been developed to estimate geotechnical parameters based on Cone Penetration Test (CPT) data for various types of soils. This paper aims to classify soil types based on CPT data with several semi-empiric correlations and compare the results of some of these correlations. In this study, the field CPT and the laboratory test were carried out on soil from two closely spaced locations in the estuary area of Muaro Baru, Padang city. The CPT data was used to determine the soil type using several semi-empirical correlations, namely; friction ratios, Schertmann (1978), Robertson and Campanella (1983), and Robertson et al. (1986), then updated by Robertson in 2010. Soil Behaviour Type (SBT) is based on the cone resistance (qc), sleeve friction (qs), and friction ratio (Rf). The Unified Soil Classification System (USCS) is also used to classify soils using sieve analysis. The results showed that from the several semi-empirical correlations obtained compatibility soil classification and soil profiles.

Convective Heat Transfer at Minimum Fluidization Velocity for Gas-Solid Fluidized Beds

1999 ◽  
Author(s):  
Kal R. Sharma
Keyword(s):  
Heat Transfer ◽  
Fluidized Beds ◽  
Empirical Correlations ◽  
Transfer Coefficients ◽  
Minimum Fluidization Velocity ◽  
Heat Transfer Coefficients ◽  
Fluidization Velocity ◽  
Minimum Fluidization ◽  
Semi Empirical ◽  
The Heat Transfer Coefficient

Abstract Experimentally measured values for the minimum fluidization velocities and time averaged local surface heat transfer coefficients are provided for 16 different cases of fluidizing conditions for gas-solid dense fluidized beds. Semi-empirical Correlations for the minimum fluidization velocity and the heat transfer coefficient at minimum fluidization velocities are provided. The implications of the Peclet number dependence in terms of diffusion and convection is discussed.

scholarly journals Development of small-scale unmanned hydrofoil boats

2020 ◽  
pp. 1-12
Author(s):  
Noah T. Thompson ◽  
Phillip R. Whitworth ◽  
Konstantin I. Matveev
Keyword(s):  
Small Scale ◽  
Empirical Correlations ◽  
Unmanned Surface Vehicles ◽  
High Speeds ◽  
Carbon Fiber Cloth ◽  
Measuring Module ◽  
Design Calculations ◽  
Semi Empirical ◽  
Maritime Community

Unmanned boats have gained a lot of interest in the maritime community during the last decade. Most hydrodynamic platforms employed for unmanned boats are based on traditional relatively simple hulls. In the present study, small-scale hydrofoil-assisted unmanned boats (0.6–0.7 m in length and 3.5–5.5 kg in mass) have been developed and tested. Design calculations using a hydrodynamic transverse-strip engineering method with semi-empirical correlations were applied to determine suitable dimensions for hydrofoil systems. The boat hulls and hydrofoils were fabricated by laying up carbon-fiber cloth sheets on foam cores or 3-D printed profiles. The boats were instrumented with outboard propulsors and electronic equipment for operations in both remote control and autopilot modes. In addition, an in-situ thrust-measuring module was designed and installed at the hull sterns to gather thrust data at GPS-measured speeds in the range between 0 and 11 m/s. The developed boats proved to be robust platforms capable of going over 600 m distances at high speeds while autonomously following preset paths. The presented methods and results can assist engineers developing unmanned surface vehicles that utilize advanced hydrodynamic concepts.

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.

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