Effect of slot depth on the evaluation of permeance in the aligned position for identically slotted rectilinear tooth geometry can be carried out using conformal transformations…
Abstract
Effect of slot depth on the evaluation of permeance in the aligned position for identically slotted rectilinear tooth geometry can be carried out using conformal transformations. Consequent increase of permeance is related to the airgap proportion ratios; tooth‐width to tooth‐pitch, t/λ; tooth‐pitch to airgap dimension, λ/g; and slot‐depth to slot‐d/s; through two intermediate parameters. Efficient search routine is used to find a suitable combination of these two parameters corresponding to given proportions of tooth and slot. For λ/g larger than 80 and d/s between 0.3 and 1, the effect of slot depth is negligible, but for λ/g equal to or less than 80 a family of permeance correction factor curves is obtained which may be used to correct for finite slot depth in permeance calculations based on infinitely deep slots. This effect is important in stepping and switched reluctance motors, particularly those with multiple teeth per stator pole.
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Method of unaligned permeance determination for a doubly‐salient rectilinear airgap with infinite slot depth is used in order to cover a wider range of gap geometry. The results…
Abstract
Method of unaligned permeance determination for a doubly‐salient rectilinear airgap with infinite slot depth is used in order to cover a wider range of gap geometry. The results are arranged in a more convenient form than is available in the literature. A set of new correction factor curves for finite slot depth and taper are then obtained. These data can directly give the unaligned permeance of a rectilinear slotted geometry for given airgap proportions (t/λ and λ/g, where λ is the tooth pitch, t is the tooth width and g is the airgap length). A wide and useful range of airgap proportions are covered, the aim having been to encompass all geometries likely to be of practical importance.
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In Table IV. are given the averages of the three samples of each cow's milk given morning and evening. The average fat for the three samples of the milk of cow A is 3.92; cow B…
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In Table IV. are given the averages of the three samples of each cow's milk given morning and evening. The average fat for the three samples of the milk of cow A is 3.92; cow B, 3.26; and cow C, 3.24, and if these were all mixed together the average fat would be 3.45 for the morning milk. The average fat of the three samples taken from the cows A, B, and C in the afternoon is—A, 5.08; B, 3.08; and C, 3.54; and the average of the three milks is 3.85. In the same table are shown the first two samples of each cow's milk mixed together both morning and evening. By referring to Tables II. and III. under cow A it will be seen that the milk fat of the first and second samples is 2.30 and 3.67, and these added together are shown on Table IV. under cow A, and similarly with cow B and cow C night and morning. It will also be seen that the milk fat in the morning milk of cow A is 3.21; cow B, 2.49; and cow C, 2.15, and if these were mixed together the average fat would be 2.61. The average fat of two samples of milk taken from cow A in the afternoon is 4.50; cow B, 2.67; cow C, 2.12, and if mixed together the average fat is 3.08. It is interesting to note that if cow B was milked for six minutes in the morning, and the milk sold, the sample would be .51 deficient in fat, and the dairyman could honestly say that the milk was sold as it came from the cow. There is also a deficiency in the fat of the milk of cow C in the morning, and cows B and C in the afternoon.
Communications regarding this column should be addressed to Mrs. Cheney, Peabody Library School, Nashville, Term. 37203. Mrs. Cheney does not sell the books listed here. They are…
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Communications regarding this column should be addressed to Mrs. Cheney, Peabody Library School, Nashville, Term. 37203. Mrs. Cheney does not sell the books listed here. They are available through normal trade sources. Mrs. Cheney, being a member of the editorial board of Pierian Press, will not review Pierian Press reference books in this column. Descriptions of Pierian Press reference books will be included elsewhere in this publication.
The Milk (Amendment) Order, 1917, which came into force on December 31st, provides that milk shall be sold retail only by Imperial measure; that no colouring matter shall be added…
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The Milk (Amendment) Order, 1917, which came into force on December 31st, provides that milk shall be sold retail only by Imperial measure; that no colouring matter shall be added to milk or cream intended for sale; that no milk to which any water has been added shall knowingly be sold or offered for sale; that no person may use for the purpose of his trade any milk can or milk bottle which bears the name, trade name, trade mark, or trade device of some person other than himself or his employer, except with the consent of such person. The Order contains a new clause, in substitution for Clauses 4 and 6 of the Milk Order, 1917 (which are revoked), providing that where milk is sold wholesale by or on behalf of any person other than the producer the maximum prices chargeable shall, unless otherwise determined, pursuant to the Order, be as follows:—
Birding, the active seeking out and identification of birds, is a wide‐spread and fast growing avocation on this continent, and indeed throughout the world. Jon Rickert's A Guide…
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Birding, the active seeking out and identification of birds, is a wide‐spread and fast growing avocation on this continent, and indeed throughout the world. Jon Rickert's A Guide to North American Bird Clubs lists 17 national/continental organizations for both professional ornithologists and amateur birders and 844 state, provincial, and local associations. In addition, there are those legions of “unorganized” bird watchers and occasional, inquisitive discoverers of backyard birds. Members of this diverse congregation of birders have at least one thing in common — the need for a reliable identification tool enabling them to correctly label the just‐seen, unfamiliar bird. A field guide is just such a tool.
It is now forty years since there appeared H. R. Plomer's first volume Dictionary of the booksellers and printers who were at work in England, Scotland and Ireland from 1641 to…
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It is now forty years since there appeared H. R. Plomer's first volume Dictionary of the booksellers and printers who were at work in England, Scotland and Ireland from 1641 to 1667. This has been followed by additional Bibliographical Society publications covering similarly the years up to 1775. From the short sketches given in this series, indicating changes of imprint and type of work undertaken, scholars working with English books issued before the closing years of the eighteenth century have had great assistance in dating the undated and in determining the colour and calibre of any work before it is consulted.
This paper focuses on the concept of fit as a topic of research. The concept of fit has been viewed as an internal consistency among key strategic decisions or the alignment…
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This paper focuses on the concept of fit as a topic of research. The concept of fit has been viewed as an internal consistency among key strategic decisions or the alignment between strategic choices and critical contingencies with the environment (external), organization (internal), or both (external and internal). A number of research perspectives or approaches related to fit are presented.Research design problems are discussed: definition of terms, theoretical issues, and empirical issues. Emphasis is on how key variables or dimensions of fit are defined and measured in research.
A six-celled matrix is proposed as a conceptual scheme to distinguish different perspectives of fit and to portray congruence relationships more accurately. The matrix includes three common dimensions: strategy, organization, and environment. The matrix also suggests two levels of strategy—corporate or business—and three domains of fit—external, internal, or integrated. These suggest different research perspectives for the study of fit. Examples from the literature are provided to illustrate and support this conceptual scheme. Finally, implications for management and furtherstudy are outlined.
The Professors of the Imperial College of Science and Technology have addressed to Lord Crewe, the Chairman of the Governors of the College, a memorial urging the necessity of the…
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The Professors of the Imperial College of Science and Technology have addressed to Lord Crewe, the Chairman of the Governors of the College, a memorial urging the necessity of the encouragement of science and of research. In commenting upon this document the Journal of Chemical Technology observes that “a satisfactory feature of the memorial is the recognition on the part of the signatories that scientific education should be on broad lines.” “We have always contended that an indispensable preliminary to a professional career should be a thoroughly sound general education. Whether or not the study of science is the best kind of study may be a debatable point, but it is certain that exclusive attention to science is thoroughly bad. A man's mind is narrow when he is unable to recognise the importance of things outside his own particular sphere of action, and it is precisely this state of mind that the exclusive study of science tends to produce. It is, therefore, the more necessary, in seeking to secure greater attention to scientific studies in the reform of our educational system, to take care that nothing be done which may curtail the period required for the acquisition of general knowledge. It is far better to delay than to hasten specialisation. A step in the right direction has been made when scientific men themselves state that they do not believe that “an education which includes good teaching of science need be a narrow education,” but we wish that this opinion had been positively rather than negatively expressed. The memorial refers to the “lethargy, misconception, and ignorance” of the public regarding national education. It is pertinent here to remark that when anything goes wrong and no particular individual or individuals can be held to be, or will acknowledge themselves to be, responsible, the “public” is blamed; the public being everybody with the exception of the denunciator and his friends. In the present instance the fault is not, even for the greater part, with the people. They are, naturally enough, interested in education only in so far as it is expressed in terms of school and college accounts and of wage‐earning capacity. Of the bearing that improvement in education and the advancement of physical science has on the welfare of the community the average man knows little and cares less. He has to be educated in the value of education. He is not, and probably never will be, interested in education as an abstract good. What interest he has in it is purely utilitarian. If he sees that the knowledge which he himself does not possess carries with it but doubtful prospects for the future, poor remuneration in the present and a social position little better than his own, he is unlikely to be impressed with the value of education. The fact is that there is a lamentable want of opportunity for the intellectual classes in this country and until this state of things is remedied the public will continue to display—and with every justification — “lethargy, misconception, and ignorance” in respect to national education.
Aarhus Kommunes Biblioteker (Teknisk Bibliotek), Ingerslevs Plads 7, Aarhus, Denmark. Representative: V. NEDERGAARD PEDERSEN (Librarian).