A numerical method is presented for the solution of the differential equation for temperature distribution along a filament heated electrically and subjected to heat loss by radiation according to the Stefan-Boltzmann...
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A numerical method is presented for the solution of the differential equation for temperature distribution along a filament heated electrically and subjected to heat loss by radiation according to the Stefan-Boltzmann law and heat conductivity (effect of leads). The solution can be precisely found if the temperature calculation is started from the filament centre. In this way reliable temperature and resistance distributions are obtained at division of the whole length into a few hundred pieces. The calculated results are compared with Langmuir's experimental data, which demonstrates the great usefulness and reliability of this approach. (C) 1998 Elsevier Science Ltd. All rights reserved.
In the technical literature of computer science, the concept of an effective procedure is closely associated with the notion of an instruction that precisely specifies an action. Turing machine instructions are held u...
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In the technical literature of computer science, the concept of an effective procedure is closely associated with the notion of an instruction that precisely specifies an action. Turing machine instructions are held up as providing paragons of instructions that "precisely describe" or "well define" the actions they prescribe. Numerical algorithms and computer programs are judged effective just insofar as they are thought to be translatable into Turing machine programs. Nontechnical procedures (e.g., recipes, methods) are summarily dismissed as ineffective on the grounds that their instructions lack the requisite precision. But despite the pivotal role played by the notion of a precisely specified instruction in classifying procedures as effective and ineffective, little attention has been paid to the manner in which instructions "precisely specify" the actions they prescribe. It is the purpose of this paper to remedy this defect. The results are startling. The reputed exemplary precision of Turing machine instructions turns out to be a myth. Indeed, the most precise specifications of action are provided not by the procedures of theoretical computer science and mathematics (algorithms) but rather by the nontechnical procedures of everyday life. I close with a discussion of some of the rumifications of these conclusions for understanding and designing concrete computers and their programming languages.
In X-ray crystallographic analysis, correct trial structures are refined by least-squares method. The detailed differential coefficients for the parameters of the calculated structure factor F-c(h) can not be found in...
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In X-ray crystallographic analysis, correct trial structures are refined by least-squares method. The detailed differential coefficients for the parameters of the calculated structure factor F-c(h) can not be found in any papers, textbooks, nor user's manual of several crystallographic computer systems. We describe, firstly, the basic expression of the structure factors, F-o(h) and F-c(h), anomalous dispersion terms of the structure factor, and then least-squares refining of \F-o(h)\ and F-o(h)(2) for use in teaching, education and computer programming. Secondly we derive the differential terms of the structure factors, solve the normal equation by diagonal, block and full-matrix approximations, and apply these to the revised computer program LSBF in DS*SYSTEM. Several practical tests are performed for these differentiations. (C) 2000 Elsevier Science Ltd. All rights reserved.
The data analyzing method of mass spectrum for regular polymers was standardized, and a computer program of the analysis was made. For many peaks, the program semi-automatically executes a correction of base line, fra...
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The data analyzing method of mass spectrum for regular polymers was standardized, and a computer program of the analysis was made. For many peaks, the program semi-automatically executes a correction of base line, fractionation, normalization and calculation of average molecular weight, and collects some series of peaks having some different molecular structures and then calculates their molar ratios. Bisphenol A polycarbonate was used as the analyzing example.
In the present paper a three-dimensional non-linear truss element and a short computer program for the modeling and predicting approximate lateral deflections in thin glass plates by the method of incremental loading ...
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In the present paper a three-dimensional non-linear truss element and a short computer program for the modeling and predicting approximate lateral deflections in thin glass plates by the method of incremental loading are proposed. Due to the out-of-plane large deflections of thin glass plates compared to the plate thickness within each loading increment, the equilibrium and stiffness conditions are written with respect to the deformed structure. An application is presented on a thin fully tempered monolithic rectangular glass plate, laterally supported around its perimeter subjected to uniform wind pressure. The results of the analysis are compared with published experimental results and found to have satisfactory approximation. It is also observed that the large deflections of a glass plate lead to a part substitution of the bending plate behavior by a tensioned membrane behavior which is favorable.
The purpose of the paper is to find the optimal criteria for interfeeder switching in a distribution system during emergency conditions. A feeder in a distribution system usually has several interfeeder switches prope...
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The purpose of the paper is to find the optimal criteria for interfeeder switching in a distribution system during emergency conditions. A feeder in a distribution system usually has several interfeeder switches properly located along the feeder to link with other feeders. Under emergency conditions, such as when faults occur on the distribution feeder, these switches are operated interdependently to minimise the loss of load and to prevent overload or unbalance power flow on the distribution feeders. In the paper, a computer program is developed to find the optimal switching algorithm. The cost function of the switching operation is defined, and the bipartite graph network is constructed according to the configuration of the distribution system. The binary integer programming (BIP) technique is used to minimise the objective function which is set up based on the relief of feeder overloading and unbalance. A distribution system comprising several substations in the Taiwan Power Company is selected for the simulation of optimal switching and the accuracy and efficiency of this program are verified.
Predicting crystal habits under the influence of additives by means of molecular modeling software (e.g., Cerius(2)) requires additionally models in order to find the final crystal habit. Here, Periodic Bond Chains (P...
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Predicting crystal habits under the influence of additives by means of molecular modeling software (e.g., Cerius(2)) requires additionally models in order to find the final crystal habit. Here, Periodic Bond Chains (PBC-vectors), are used to improve the results of one of these model approaches, the build-in approach [1,2]. The build-in approach does not always produce the desired results. A computer program was developed to find the PBCs and to investigate their changes as a result of the presence of additives. This approach is verified using the examples of benzophenone with different additives. Furthermore, the results are discussed and problems are highlighted.
The paper discusses the maintenance of both pumped storage and conventional hydro-electric plant in the United Kingdom, dealing specifically with the experiences of one Group of the North of Scotland Hydro-Electric Bo...
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The paper discusses the maintenance of both pumped storage and conventional hydro-electric plant in the United Kingdom, dealing specifically with the experiences of one Group of the North of Scotland Hydro-Electric Board. The types of hydro-electric plant considered are geographically well spread and are subject to a number of different hydraulic regimes. A computer program developed for the best utilisation of maintenance resources entitled ‘generation equipment maintenance’ (GEM) is introduced and discussed.
Absorption often influences the structure of a whole process. Until now, systematically planning of absorption as a part of an entire process and estimating the prospect of success for probable absorption process alte...
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Absorption often influences the structure of a whole process. Until now, systematically planning of absorption as a part of an entire process and estimating the prospect of success for probable absorption process alternatives for a given separation problem with a minimum of existing information was difficult and time consuming. Presented is a heuristic‐numeric approach for the systematic development and design of absorption processes.
The enzyme, bromelain, is known to catalyze protein proteolysis and to activate many protective processes occurring with participation of the nervous, immune, and endocrine systems. In this connection, a computer anal...
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The enzyme, bromelain, is known to catalyze protein proteolysis and to activate many protective processes occurring with participation of the nervous, immune, and endocrine systems. In this connection, a computer analysis of all the possible 4-6-member fragments of bromelain was performed by means of a comparison of their primary structures with amino acid sequences of all the known natural oligopeptides. Information from the EROP-Moscow data base that contains data on the structures and functions of natural oligopeptides and specially written computer programs were used for this purpose. It was shown that tetra-, penta-, and hexapeptide fragments of the bromelain molecules are involved in amino acid sequences of many natural oligopeptides, including antimicrobial oligopeptides, toxins, neuropeptides, and hormones. These results confirmed deep relationship between the basic regulatory systems. In connection with the obtained data, the process of oligopeptide biogenesis, the possibility of natural formation of regulatory oligopeptides from the bromelain molecules, and correspondence of the obtained results with the conception of oligopeptide continuum are discussed. A possible practical importance of active fragments of protein enzymes in regulatory processes of a living organism is noted.
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