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The Solution of Special Problems

However, analyzing the flow diagram we can see that units 3 and 4 are connected by parallel streams thus, the balance around unit 4 (b4) is substituted by a balance around unit 3 and 4 (b(3 + 4)). The new balances are now [Pg.39]

By obtaining the output set assignment on the previous set of balances we can classify the unmeasured process variables as determinable or nondeterminable. The results are given in Table 5 this classification is coincident with those from other works cited in the literature. [Pg.39]

Once the process variables have been classified, a great deal of information about the process topology is also available. The question now is how to use the classification and this information to attack other problems. In a real process we will have different kind of problems to solve and the goals will vary from one process to another. Among the possible situations that may be encountered are the following  [Pg.39]

Using a classification algorithm we can determine the measured variables that are overmeasured, that is, the measurements that may also be obtained from mathematical relationships using other measured variables. In certain cases we are not interested in all of them, but rather in some that for some reason (control, optimization, reliability) are required to be known with good accuracy. On the other hand, there are unmeasured variables that are also required and whose intervals are composed of over measured parameters. Then we can state the following problem Select the set of measured variables that are to be corrected in order to improve the accuracy of the required measured and unmeasured process variables. [Pg.39]

Consider a system that after the classification has all the unmeasured variables determinable. Suppose also that the system under study has some overmeasured variables. Then we want to select which of the overmeasured variables need not be measured, while preserving the condition of determinability for the unmeasured variables. That is, we want to minimize the number of measurements in such a way that all the unmeasured variables are determinable. This problem can be stated as [Pg.39]


It is the study of differential equations of this kind which leads to the special functions of mathematical physics. The adjective special is used in this connection because here we arc not, as in analysis, concerned with the general properties of functions, but only with the properties of functions which arise in the solution of special problems. [Pg.3]

The molecular cross section of the ordinary Raman effect can be considerably enhanced. If the exciting radiation has a higher frequency, the intensity increases basically by the fourth power of the frequency. Moreover, there is a further increase as electronic absorption bands are approached the pre-resonance and resonance Raman effect (Sections 3.6 and 6.1). Further, the so-called surface-enhanced Raman effect (SERS) increases the molecular cross section. Both effects produce an enhancement of several orders of magnitude (Gerrard, 1991) (see Sec. 6.1). However, these two effects have to be carefully adapted to the specific properties of the investigated molecules. Photochemical decomposition and excitation of fluorescence may make it impossible to record a Raman spectrum. The described techniques may thus be of considerable importance for the solution of special problems, but they are by no means routine techniques to be generally used. [Pg.120]

The above procedures are suitable for the purification of relatively large amounts of solvent (in the litre range). Preparative gas chromatography has proved the most suitable method for the preparation of small portions of solvents (50-500 mg) of special purity. However, the resulting extremely pure solvents are required only for the solution of special problems on the micro scale. [Pg.254]

Many simplified procedures can be used for seismic design and re-evaluation purposes in the solution of special problems for example ... [Pg.66]

Dimer-based p. are used as ->hot-melt adhesives in product assembly with excellent adhesion to hydrophobic surfaces (plastics, greasy metals) but also to paper and wood. They are used in the shoe and automotive industries, in cable joints and other electrical applications. The higher price, compared to normal hot melts, limits the application to the solution of special problems. [Pg.227]

Because of the presence of Q g and Q2e in Equation (2.84) and of 3 g and 326 f Equation (2.87), the solution of problems involving so-called generally orthotropic laminae is more difficult than problems with so-called specially orthotropic laminae. That is, shear-extension coupling complicates the solution of practical problems. As a matter of fact, there... [Pg.78]

While H NMR is an important tool, which requires some 10-100 p,g, it yields organic structural information only indirectly (viewed through the hydrogen nuclei). In principle, the 13 C nucleus is the most informative probe for organic structure determination by means of FTNMR. The special advantages, which make 13C NMR an attractive alternative to 1H NMR for the solution of analytical problems, include ... [Pg.329]

Partial derivatives, as introduced in Section 2.12 are of particular importance in thermodynamics. The various state functions, whose differentials are exact (see Section 3.5), are related via approximately 1010 expressions involving 720 first partial derivatives Although some of these relations are not of practical interest, many are. It is therefore useful to develop a systematic method of deriving them. Hie method of Jacobians is certainly the most widely applied to the solution of this problem. It will be only briefly described here. For a more advanced treatment of the subject and its application to thermodynamics, die reader is referred to specialized texts. [Pg.295]

Besides silica, silica-based and polymeric stationary phases, porous graphitized carbon (PGC), zirconium oxide and its derivatives, alumina and its derivatives have been used for the solution of special separation problems which cannot be easily solved by using traditional HPLC stationary phases. [Pg.19]

Such a calculation had to be made in determining the problem of interaction between a diatomic polar molecule and an atom with a closed electronic shell [1,2]. The solution of this problem was of special importance in connection with the nature of the hydrogen bond. Our investigations were based on a definite hydrogen bond model that was verified by mathematical treatment and comparison with experimental results. This model is essentially different from that criticized by Dr. Burawoy. Its main point can be explained as follows [2, 3]. [Pg.391]

Not long ago a number of calculational methods were routinely used for the manual solution of special problems such as the calcn of compn of rocket exhaust gases (Refs 10 14). [Pg.686]

There are two distinct problems to be considered regarding the genetic code the replication of DNA and the synthesis of RNA, on one hand, and the synthesis of proteins, on the other. Numerous contributions have been made towards the solution of these problems. Being concerned here with the quantum mechanical aspects, it is not possible to review them, but special mention should be made to the work13 carried out by the groups of Crick, Khorana, Nirenberg, and Ochoa. [Pg.45]

There is no doubt that systems research requires a multidisciplinary team, in which all relevant specialisms are represented - not by those who are second-rate, but by those who have a high standing in their subject and are thus able to harness their branch of science to the solution of multidisciplinary problems. Furthermore, these specialists need to continue in their own fields, in order that they should be both up-to-date and credible representatives of it. [Pg.186]

It is in the measure that special methods acknowledge their common core in transcendental method, that norms common to all the sciences will be acknowledged, that a secure basis will be attained for tackling interdisciplinary problems, and that the sciences will be mobilized within a higher unity of vocabulary, thought and orientation, in which they will be able to make their quite significant contribution to the solution of fundamental problems. [Pg.309]

The special type of carbonyl-group derivatization is aimed for gas chromatography-mass spectrometry (GC-MS) determination of double-bond C = C positions in the unsaturated long-chain acids. The analytical derivatives for the solution of this problem are nitrogen-containing heterocycles. These compounds can be synthesized by condensation of carboxylic acids with 2-amino-2-methyl-l-propanol (2-substituted 4,4-dimethyloxazolines), 2-aminophenol (2-substituted benzoxazoles), and so forth. [Pg.489]

In principle, owing to its generality, the Schrodinger equation contains the solution of all problems of molecular structure. Unfortunately, it is only integrable in a few special cases, the hydrogen atom for instance. [Pg.6]

One of the most important applications of the differential calculus is the determination of maximum and minimum values of a function. Many of the following examples can be solved by special algebraic or geometric devices. The calculus, however, offers a sure and easy method for the solution of these problems. [Pg.155]

Typically, rapid repair of main cracks in slabs is realized using bituminous masses covering only the damages. Unfortunately, this kind of protection is ineffective just after few months of exploitation, because the degraded mass (Fig. 2b, 2c) allows for infiltration of water under slabs [8]. The coming into being hydrodynamic pump effect (due to moving loads - Fig. 3a) destructs sealants in joints (Fig. 3b) and causes uneven settlement of concrete slabs (Fig. 3c). The solution of this problem is the use of special polymer flexible joints. [Pg.227]

In this section we will briefly discuss some variations of saturation, polarization, or multiphoton spectroscopy that either increase the sensitivity or are adapted to the solution of special spectroscopic problems. They are often based on combinations of several nonlinear techniques. [Pg.138]

Most universal methods of derivatization of acids are silylation (TMS or TBDMS) and alkylation (the simplest methyl esters with minimal retention parameters are preferable among all possible derivatives). Other methods involve an auxiliary predetermination and can be recommended for the solution of special analytical problems. [Pg.8]

One could argue that this phase of development in solid state physics was concluded by the publication of Voigt s famous textbook in 1910. The underlying reason is the importance of the symmetry of crystals for all other properties. However, a good imderstanding of the thermodynamics is of utmost importance for the solution of all problems in the physics of crystals. We could say that for a physicist further development of thermodynamics is less important than the development of microscopic models. For all technical appUcations, however, thermodynamics is of special importance. [Pg.8]

The analytical solution of these three-dimensional coupled equations can be accomplished for only very specialized states of deformation (Selvadurai 2007). For this reason, computational approaches have been developed for the solution of poroelasticity problems a finite element scheme is used here to solve this problem. [Pg.191]


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Solution of the problem

Special Problems

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