The physical sense of simulation models of liquid chromatography: propagation through a grid or solution of the mass balance equation

1990 ◽  
Vol 62 (2) ◽  
pp. 189-200 ◽  
Author(s):  
Martin. Czok ◽  
Georges. Guiochon
Keyword(s):  
Liquid Chromatography ◽  
Mass Balance ◽  
Balance Equation ◽  
Simulation Models ◽  
Mass Balance Equation ◽  
Physical Sense

scholarly journals The influence of traffic and wood combustion on the stable isotopic composition of carbon monoxide

2008 ◽  
Vol 8 (6) ◽  
pp. 19561-19604
Author(s):  
M. Saurer ◽  
A. S. H. Prévôt ◽  
J. Dommen ◽  
J. Sandradewi ◽  
U. Baltensperger ◽  
...  
Keyword(s):  
Carbon Monoxide ◽  
Isotopic Composition ◽  
Mass Balance ◽  
Balance Equation ◽  
Isotope Ratio ◽  
Rural Site ◽  
Mass Balance Equation ◽  
Wood Combustion ◽  
Isotope Mass Balance ◽  
The Village

Abstract. Carbon monoxide in the atmosphere is originating from various combustion and oxidation processes. Recently, the proportion of CO resulting from the combustion of wood for domestic heating may have increased due to political measures promoting this renewable energy source. Here, we used the stable isotope composition of CO (δ13C and δ18O) for the characterization of different CO sources in Switzerland, along with other indicators for traffic and wood combustion (NOx-concentration, aerosol light absorption at different wavelengths). We assessed diurnal variations of the isotopic composition of CO at 3 sites during winter: a village site dominated by domestic heating, a site close to a motorway and a rural site. The isotope ratios of wood combustion emissions were studied at a test facility, indicating significantly lower δ18O of CO from wood combustion compared to traffic emissions. At the village and the motorway site, we observed very pronounced diurnal δ18O-variations of CO with an amplitude of up to 8‰. Solving the isotope mass balance equation for three distinct sources (wood combustion, traffic, clean background air) resulted in diurnal patterns consistent with other indicators for wood burning and traffic. The average night-time contribution of wood-burning to total CO was 70% at the village site, 47% at the motorway site and 28% at the rural site based on the isotope mass balance. As this analysis showed a strong sensitivity towards the pure source isotope values, we additionally applied a combined CO/NOx-isotope model for verification. Here, we separated the CO emissions into different sources based on different CO/NOx emissions ratios for wood combustion and traffic, and inserted this information in the isotope mass balance equation. Accordingly, a highly significant agreement between measured and calculated δ18O-values of CO was found (r=0.67, p<0.001). While different proxies for wood combustion all have their uncertainties, our results indicate that the oxygen isotope ratio of CO (but not the carbon isotope ratio) is an independent sensitive tool for source attribution studies.

scholarly journals Validating The Core Concept Of “Mass Balance”

2021 ◽  
Vol 45 (2) ◽  
pp. 276-280
Author(s):  
Joel Michael ◽  
Harold Modell
Keyword(s):  
Conceptual Framework ◽  
Mass Balance ◽  
Balance Equation ◽  
Teaching And Learning ◽  
Mass Balance Equation ◽  
Core Concept ◽  
Conceptual Frameworks ◽  
The Core ◽  
Making Sense ◽  
Fundamental Mass

We have created a conceptual framework for the core concept of “mass balance.” Unlike the previous conceptual frameworks that we have created and validated, the framework for “mass balance” is simply a description in words of the fundamental mass balance equation and the implications of the equation. We surveyed physiology faculty and asked them to rate the importance of “mass balance” as defined by the conceptual framework and also to rate the importance for their students of being able to apply the core concept to liquids, gases, solutes, and solids. Respondents indicated that “mass balance” is important and that our conceptual framework provides a useful tool for teaching and learning. We discuss several examples of how “mass balance” can be used in making sense about a variety of physiological phenomena.

Pemodelan Kesetimbangan Massa pada Keadaan Tunak (Steady) sebagai Penentuan Konsentrasi Optimum Tawas (Alumunium Sulfate) pada Proses Penurunan Kadar Fe pada Sumber Air Tercemar

2020 ◽  
Vol 4 (2) ◽  
pp. 128
Author(s):  
Alfiana Adhitasari ◽  
Eko Andrijanto
Keyword(s):  
Experimental Data ◽  
Mass Balance ◽  
Balance Equation ◽  
Calculated Data ◽  
Source Water ◽  
Mathematical Equation ◽  
Mass Balance Equation ◽  
Fe Content ◽  
Fe Reduction

Air tanah merupakan andalan sumber mata air bagi masyarakat pada umumnya, beberapa sumber air tanah sering dijumpai air yang masih terkandung Fe, hal tersebut berdampak buruk bagi kesehatan oleh karena itu perlu dilakukan penuruan kadar Fe pada air sebelum digunakan. Beberapa metode yang umum dilakukan untuk menghilangkan kandungan Fe pada air adalah dengan cara koagulasi oleh tawas. Penelitian ini akan memodelkan sebuah persamaan matematika yang dapat mengkuantifikasi penurunan kadar Fe pada setiap fungsi kosentrasi tawas yang ditambahkan. Model matematika pada penelitian menggunakan penurunan rumus dari kesetimbangan masa. Dari hasil perbandingan data percobaan dengan data perhitungan didapat konstanta penurunan Fe (kF) pada fungsi konsentrasi tawas sebesar 1.8/mg tawas dan nilai konstanta R2 sebesar 0.935, dari data tersebut maka model matematika yang dibuat dapat mewakili fenomena proses penurunan Fe di lapangan.In general groundwater is relied as source water but somtimes we found precense of Fe in some of groundwater products that could harm our health due to its toxicity, therefore it is necessary to reduce Fe content as pretreatment process. Some common methods to reduce Fe content in water are coagulation by alum. This study will build a mathematical equation to quantify the reduction of Fe content in function of alum concentration. In this study the equations were derive from mass balance equation. By comparing the experimental data with calculated data, we obtained kF (The constant of consuming Fe) = 1.8 / mg alum and for R2 constant we obtained  0.935, from these result we conclude our derived equation can represent the phenomenon of alum-Fe reduction phenomena in the field.

A solution of the inorganic carbon mass balance equation and its relation to algal growth rates

1974 ◽  
Vol 10 (3) ◽  
pp. 493-497 ◽  
Author(s):  
Mahlon G. Kelly ◽  
M. Robbins Church ◽  
George M. Hornberger
Keyword(s):  
Mass Balance ◽  
Growth Rates ◽  
Balance Equation ◽  
Inorganic Carbon ◽  
Algal Growth ◽  
Mass Balance Equation ◽  
Carbon Mass Balance ◽  
Carbon Mass

The Forecasting of Hydrogen Sulphide Gas Build-Up in Sewerage Collection Systems

1992 ◽  
Vol 26 (3-4) ◽  
pp. 915-922 ◽  
Author(s):  
J. S. Matos ◽  
E. R. de Sousa
Keyword(s):  
Mathematical Model ◽  
Atlantic Ocean ◽  
Mass Balance ◽  
Hydrogen Sulphide ◽  
Balance Equation ◽  
Experimental Information ◽  
Common Source ◽  
Mass Balance Equation ◽  
Main Trunk

The presence of hydrogen sulphide gas in sewerage collection systems is a common source of odour nuisance, corrosion of sewers and toxic atmospheres. The hydrogen sulphide build-up in the sewer air may be related to sulphide concentrations in the flowing sewage and with other factors, such as turbulence, aerodynamic conditions of the ventilating air now and roughness of the unsubmerged surfaces. In the present work, a mathematical model is presented for forecasting hydrogen sulphide gas build-up along gravity sewers, which is based on the analysis of a differential mass balance equation applied to a sewer reach. Good correlation was obtained, comparing the results of the model with experimental information collected in the Funchal main trunk sewer. Funchal city is the capital of Madeira, a Portuguese island in the middle of the Atlantic Ocean, and its main trunk sewer was put into operation at the beginning of 1980.

scholarly journals Diffusion in Semiconductors by Using Fourier Series Expansion Technique

2014 ◽  
Vol 11 (2) ◽  
pp. 90-97
Author(s):  
M El-Adawi ◽  
S Abdel-Ghany ◽  
S Shalaby
Keyword(s):  
Fourier Series ◽  
Diffusion Equation ◽  
Mass Balance ◽  
Series Expansion ◽  
Theoretical Approach ◽  
Balance Equation ◽  
Concentration Function ◽  
Fourier Series Expansion ◽  
Mass Balance Equation ◽  
Expansion Technique

Doping by diffusion is still one of acceptable and important methods that have essential technological applications. A theoretical approach to study diffusion in semi-conductors is introduced. The diffusion equation together with Fick's law and mass balance equation are solved to obtain the concentration function and the mass penetration depth using Fourier Series expansion technique. Doping of indium, phosphorus, gallium and Arsenic in Silicon as illustrative examples are given.

scholarly journals AN EVALUATION OP MIXING IN THE TAY ESTUARY

1972 ◽  
Vol 1 (13) ◽  
pp. 119
Author(s):  
J.R. West ◽  
D.J.A. Williams
Keyword(s):  
Mass Balance ◽  
Balance Equation ◽  
Continuous Monitoring ◽  
Dispersion Coefficient ◽  
Economic Resources ◽  
Mass Balance Equation ◽  
Salinity Distribution ◽  
Field Instrumentation ◽  
Wide Range ◽  
Survey Results

The authors consider the derivation of an expression for salinity distribution in an estuary, from an instantaneous mass balance equation for a solute in a continuum. The expression is compatible with existing field instrumentation and limited economic resources. Details are given of a prototype survey which included continuous monitoring of the salinity distribution of the Firth of Tay, an estuary subject to a wide range of fluvial and marine influences. The survey results enabled an apparent dispersion coefficient to be evaluated and an estimate to be made of the net mixing.

scholarly journals The influence of traffic and wood combustion on the stable isotopic composition of carbon monoxide

2009 ◽  
Vol 9 (9) ◽  
pp. 3147-3161 ◽  
Author(s):  
M. Saurer ◽  
A. S. H. Prévôt ◽  
J. Dommen ◽  
J. Sandradewi ◽  
U. Baltensperger ◽  
...  
Keyword(s):  
Carbon Monoxide ◽  
Isotopic Composition ◽  
Mass Balance ◽  
Balance Equation ◽  
Isotope Ratio ◽  
Rural Site ◽  
Mass Balance Equation ◽  
Wood Combustion ◽  
Isotope Mass Balance ◽  
The Village

Abstract. Carbon monoxide in the atmosphere is originating from various combustion and oxidation processes. Recently, the proportion of CO resulting from the combustion of wood for domestic heating may have increased due to political measures promoting this renewable energy source. Here, we used the stable isotope composition of CO (δ13C and δ18O) for the characterization of different CO sources in Switzerland, along with other indicators for traffic and wood combustion (NOx-concentration, aerosol light absorption at different wavelengths). We assessed diurnal variations of the isotopic composition of CO at 3 sites during winter: a village site dominated by domestic heating, a site close to a motorway and a rural site. The isotope ratios of wood combustion emissions were studied at a test facility, indicating significantly lower δ18O of CO from wood combustion compared to traffic emissions. At the village and the motorway site, we observed very pronounced diurnal δ18O-variations of CO with an amplitude of up to 8‰. Solving the isotope mass balance equation for three distinct sources (wood combustion, traffic, clean background air) resulted in diurnal patterns consistent with other indicators for wood burning and traffic. The average night-time contribution of wood-burning to total CO was 70% at the village site, 49% at the motorway site and 29% at the rural site based on the isotope mass balance. The results, however, depend strongly on the pure source isotope values, which are not very well known. We therefore additionally applied a combined CO/NOx-isotope model for verification. Here, we separated the CO emissions into different sources based on distinct CO/NOx emissions ratios for wood combustion and traffic, and inserted this information in the isotope mass balance equation. Accordingly, a highly significant agreement between measured and calculated δ18O-values of CO was found (r=0.67, p<0.001). While different proxies for wood combustion all have their uncertainties, our results indicate that the oxygen isotope ratio of CO (but not the carbon isotope ratio) is an independent sensitive tool for source attribution studies.

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