Computer software packages for

The objective of the book series Developments in Environmental Science is to facilitate the publication of scholarly works that address any of the described topics, as well as those that are related. In addition to edited or single and multi-authored books, the series also considers conference proceedings and paperback computer-software packages for publication. The emphasis of the series is on the importance of the subject topic, the scientific and technical quality of the content and timeliness of the work. 

As evidenced by this example, estimation of binary diffusivities can be quite tedious. Most mass-transfer problems involve the calculation of one or more values of diffusivities. Convenience therefore suggests the use of a computer software package for technical calculations, such as Mathcad, for that purpose. Figure 1.3 shows a Mathcad routine to estimate gas-phase binary diffusivities using the Wilke-Lee equation, which, for computational purposes, gets the name... 

Saboo, A. K., Morari, M., and Colberg, R. D., RESHEX An Interactive Software Package for the Synthesis and Analysis of Resilient Heat Exchanger Networks II. Discussion of Area Targeting and Network Synthesis Algorithms, Computers Chem. Eng., 10 591, 1986. 

Although equations 5.13 and 5.14 appear formidable, it is only necessary to evaluate four summation terms. In addition, many calculators, spreadsheets, and other computer software packages are capable of performing a linear regression analysis based on this model. To save time and to avoid tedious calculations, learn how to use one of these tools. For illustrative purposes, the necessary calculations are shown in detail in the following example. 

This is a more difficult equation to solve than that for the solubility of Pb(I03)2 in distilled water, and its solution is not immediately obvious. A rigorous solution to equation 6.34 can be found using available computer software packages and spreadsheets. 

Once the objective and the constraints have been set, a mathematical model of the process can be subjected to a search strategy to find the optimum. Simple calculus is adequate for some problems, or Lagrange multipliers can be used for constrained extrema. When a Rill plant simulation can be made, various alternatives can be put through the computer. Such an operation is called jlowsheeting. A chapter is devoted to this topic by Edgar and Himmelblau Optimization of Chemical Processes, McGraw-HiU, 1988) where they list a number of commercially available software packages for this purpose, one of the first of which was Flowtran. 

J. Stadler, R. Mikulla, H.-R. Trebin. IMD a software package for molecular dynamics studies on parallel computers. Int J Mod Phys C 5 1131, 1997. 

Many computer software packages are available for energy-targeting purposes, but care should be taken in specifying the requirements and insisting on performance satisfaction and testing before final payment. Such software packages may be expensive and could require modifications for actual use. 

Scilab - scientific software package for numerical computations (Freeware) http //www.scilab.org... 

MENDES, P., GEPASI a software package for modelling the dynamics, steady states and control of biochemical and other systems, Comput. Appl. Biosci., 1993, 9, 563-571. 

This problem is an extension of problems 7-10 and 7-11 on the dehydrogenation of ethane to produce ethylene. It can be treated as an open-ended, more realistic exercise in reaction mechanism investigation. The choice of reaction steps to include, and many aspects of elementary gas-phase reactions discussed in Chapter 6 (including energy transfer) are significant to this important industrial reaction. Solution of the problem requires access to a computer software package which can handle a moderately stiff set of simultaneous differential equations. E-Z Solve may be used for this purpose. 

An ideal calibration curve (Figure 2.7) is a straight line with a slope of about 45 degrees. It is prepared by making a sequence of measurements on reference materials which have been prepared with known analyte contents. The curve is fundamental to the accuracy of the method. It is thus vitally important that it represents the best fit for the calibration data. Many computer software packages, supplied routinely with various analytical instruments, provide this facility. It is, however, useful to review briefly the principles on which they are based. 

The instrument is controlled by an IBM Think Pad laptop computer via a wireless network, utilizing ASD s proprietary software package. For this study, reference standard readings were collected before each sample reading to ensure consistent equipment function and to establish atmospheric conditions. 

Gaussian elimination is a very efficient method for solving n equations in n unknowns, and this algorithm is readily available in many software packages. For solution of linear equations, this method is preferred computationally over the use of the matrix inverse. For hand calculations, Cramer s rule is also popular. 

Computer software packages assist in matching the unknown diffraction patterns with a stored database. Problems arise if the sample contains more than one mineral species, since the pattern for each species gives rise to a complex overlapping pattern that cannot be easily interpreted. If one species can be easily identihed and its reflections subtracted from the pattern, it may then be possible to identify a second species. Three species becomes even more complicated. In such circumstances it is advisable if possible to physically sort ( pick ) the sample into different minerals under the microscope before... 

Johnson JM, Oelkers EH, Helgeson HC (1992) SUPRT92 A software package for calculating the standard molal thermodynamic properties of minerals, gases, aqueous species and reactions from 1 to 5000 bars and 0 to 1000°C. Comput Geosci 18 899-947... 

In order to obtain reproducible results, special care must be given to panel selection and panel education, testing facilities, sample presentation and the design of each test. Modern sensory facilities display a kitchen/laboratory for sample preparation as well as separate sensory booths with controlled air and lighting. The evaluation of the sensory results can be supported by specialised computer software packages. 

Kinetic analysis of tyrosinase and calculation of constants will be described using graphical analysis by the Michaelis-Menten equation, Lineweaver-Burk equation, or the direct linear curve. Procedures for preparing these graphs are described below. Alternatively, students may use available computer software to graph data and calculate kinetic constants. Recommended enzyme kinetic computer software packages include Enzyme... 

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