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A simple linear model is constructed for production, use and recycling of various paper and related products. This model is used to estimate the maximum feasible recycling rate given the current state of pulp and paper technology. Parametric linear programming is used to investigate the effect of the efficiency of collecting, sorting and transporting waste paper on the fraction recycled.

Because of the complexity of operation of a paper machine, a simulation of operation would provide three avenues through which better startup and operation could be obtained: (1) engineering evaluation, (2) operator training, and (3) control-program evaluation. Prior to the startup of a new high-speed paper machine, a simulation of the stock system where the suspended fibers are formed into a sheet of paper was undertaken. Basic information on the steady-state and dynamic be havior of such a system was obtained on a highly instru mented paper machine having components similar to those of the new machine. The system was analyzed one component at a time to fit available theoretical equations with minor modifications. This allowed reasonable extrap olation and reassembly of the system to describe the new machine. An important factor in describing such a system was the transport lag in the pipelines. This facet of the simulation was accomplished with prewired Padé approximations of these lags. A second important characteristic in describing a paper machine in real time is the long time-constants involved in the rates of change. These may run as long as 10 minutes. A replica of the main control panels was constructed for use as a training aid for the operating crews of the new machine. The panels were programmed on the computer to respond to upsets and grade changes as part of an inten sive training program for the operators. Exploitation of the simulation system is still in progress. It is evident, however, that the smooth startup resulted from careful planning and effective operator training.

This paper presents a technique for simulation of the stock preparation and Fourdrinier dynamics which is flexible, convenient, and detailed enough to allow the user to study physical process modifications and transient response dur ing upsets and "furnish" (fibers with different character istics, fillers, dyes, etc.) changes and to evaluate simplified mathematical models and control schemes. The technique uses digital simulation in a block diagram form, each block of which corresponds to one type of physical unit in the process (e.g., cleaner or tanks). Simu lation of a particular process then involves specification of the particular parameters of each physical unit together with the way in which they are interconnected. Individual components of the furnish may be traced through the whole process. A complete wet-end configuration, including the white water recovery system, is simulated using the technique described in the paper, and typical results obtained during grade changes and disturbances are presented.

Detailed engineering studies on the energy balance profile, which resulted in the establishment of related per area energy costs in the drier section of a hypothetical 300-ton-per-day paper machine, have been converted into an economic model. Based upon these data, a conceptual design on of an equivalent paper machine in which microwave energy is substitued for more con ventional energy in selected areas has been made and an equivalent economic model developed. The comparison of these economic models is then used to demonstrate the relative merits of microwave energy as a useful source of power in paper manufacture. This comparison shows that while capital cost is somewhat increased, the overalI operating cost is decreased. Significant advantages include a more uniform moisture profile, and a substantially shortened paper machine length.

In considering the mathematics program for elementary children, it is important for teachers to examine not only mathematical ideas but also the contexts within which such ideas are used. This usually means an examination of visual aids or tools of learning, since instruction in elementary grades depends upon the concrete to explain the abstract. With this in mind, one such tool that deserves special attention is graph, or squared, paper. Until one looks at the many possible uses of this visual aid, it may be taken for granted, and its applications remain sporadic and disconnected. This article is presented for the purpose of showing that graph paper is an educational device having few peers, especially from the points of view of economy, availability, and ease of use. An ordinary compilation of graph paper uses would be helpful to some degree, but what follows is a sequential development from the primary level through the upper elementary grades.

During the last two decades both the speed and width of paper machines have increased considerably. This has resulted in the adoption of many devices which prior to that time were still looked on with doubt. The increase in width and weight of the rolls of modern newsprint machines has made the removable wet end practically standard. Similarly the increase in speed has only been made possible by the use of the projection slice, suction couch, and press rolls, which are being fitted with success to machines of all types. The shells of suction rolls must be free from blowholes and this has entailed the use of centrifugal castings, and has been the means of developing their technique. A further development is the vacuum-forming paper machine, probably the most revolutionary modification of the Fourdrinier machine yet proposed. The two-wire machine gives a paper free from any wire mark, and recently a wire has been produced which goes some way towards the elimination of the wire mark. Electric drives arc nearly standard on all new machines.

This subject-author index of over 500 papers is intended as a helpful reference tool for those who seek material on the writing, verbal presentation, and publication of technical information, and as a guide to people who have authored such material. Many of the papers listed - especially those given in local society meetings - have not been published. These were included bcause frustration is preferable to total ignorance. To track down an unpublished paper or an author when all else fails, contact the organization that sponsored the meeting at which the paper was given. This index is not necessarily 100% exhaustive; some titles may have been omitted, and some misclassified. Readers are invited to notify the Transactions on EWS of errors or omissions.

This paper describes an attempt to apply linear optimal control theory to computer control of an industrial process. The applicability of the theory is discussed. Particular attention is given to the problem of obtaining a mathematical model of process dynamics and disturbances. Results of actual measurements as well as results from on-line control experience are presented.

Using the principles of elementary dynamics limits are put on the speeds with which a paper transport mechanism which is required to stop at a given character can be expected to work. It is shown that these speeds are nearly four times those so far achieved.

A simple method for the paper tape recording of ESR spectra employing an integrating analog-to-digital converter is described. A method which combines the averaging of several spectra with the smoothing of the resulting mean spectrum is compared with the more conventional practice of using some type of multichannel analyzer or storage register for improving the signal-to-noise ratio in weak spectra.

Summary A multilevel approach to design of a paper machine control system has been presented. The system described includes not only regulating and coordinating control, but also on-line optimizing algorithms. In addition to being a convenient means for organizing the control activity, the multilevel approach provides a framework for organizing the computer software. In actual operating systems, the frequently executed first level programs are core memory resident, while the remaining levels of control reside in a rapid access drum mass storage. The core-drum memory combination is an economical way to implement multilevel control structures.

The device will produce a graph from data in the form of five-track paper tape. The rate of plotting is 20 points per minute at an accuracy of up to one part in 1000. Apart from a standard ten-millivolt potentiometric recorder and tape reader, the device requires 21 transistors, 2 valves and 22 relays.

Analytical difficulties in the analysis of D&C Red No. 21 by column chromatography are overcome by using an ascending paper chromatographic technique, based on that of Graichen, followed by elution of the zones and spectrophotometric determination. Results compare well with those by column chromatography.

A high speed paper tape reader with a maximum speed of 1000 characters per second is described. Relevant principles of construction as well as operating characteristics are given in some detail.

ロ紙を水平空間に保持するopen-strip typeと,著者が自製したガラス板で口紙をはさみ密閉,冷却できるようにしたsandwich typeの2種類のロ紙固定方式にて,ロ紙上物質の移動と泳動電流によるロ紙の発熱,それに伴って生じる電解液の蒸発,ロ紙の毛細管浸透現象による電解液のロ紙中央部に向う流れとの関連について調べた.open-strip typeはロ紙の発熱が著しく,このため泳動方向,泳動像,泳動速度などに安定した結果を得ることが困難であり,また泳動電圧を高くすることは不可能に近い.これに対してsandwich typeではこれらの影響を受けにくく,再現性もえやすいうえに高電圧を加えることが可能であった.それでこのsandwich typeを用いて100V/cm程度の電位こう配にて泳動を実施できるロ紙固定台を試作し,泳動結果の再現性を簡単なグラフにて表現することを試みた.

WITHIN the last twenty years, chromatography has become increasingly important as an analytical tool. The purpose of this article is to review the uses of partition chromatography on paper, which, since its inception four years ago1, has had a wide application and which promises to become as well established as the older forms of chromatography. It should be emphasized, however, that, as mixtures, especially from biological sources, may be very complex, preliminary separations2-5 may often be necessary before paper chromatography can be used to the best possible advantage. For recent developments in all types of chromatography, the reader is referred to a number of articles indicated in footnotes 6–9.

The mere fact that a thing or person has possibilities of good in large amount is no assurance that good will result from the use of that thing or from the individual possessed of that possibility. A superficial study of existing conditions is all that is necessary to ascertain the truth of this statement. The term paper is a valuable instrument in secondary and higher education but is abused and falls far short of its possibilities, because of the clumsy use of a good technique by both teachers and pupils alike. If one was to ask a number of teachers, using this device, what purpose the term paper best served they would probably most frequently receive some form of the following statements: (1) It may be used as a supplement to the regular class work to bring in material that ordinary members will be unable to obtain due to lack of time in class or ability in the pupils; (2) It serves the purpose of offering to better pupils a chance to enrich their school work and in some cases to secure a better grade; (Grades are not what we ought to be after, but it is one thing that many teachers emphasize to the point of causing many of our students to strive for them); (3) It gives a chance for valuable training in organizing valuable data and materials into more accessible and usable form; (4) and, it serves the purpose of giving an opportunity for doing rudimentary research and thus developing skill in solving problems along the line covered by the particular course. The term paper seems to aid in developing several worth-while abilities. Students are required to state a problem in workable form and collect bibliographies covering the topic. They must evaluate, eliminate, and organize the data after they have been found and collected. Many times this takes them into libraries but frequently an experiment must be devised or some accepted form of collecting data that is not available in libraries. Conclusions must be drawn and evaluated upon the basis of adequacy of sampling and reliability of sources. Many times the conclusion is unjustified by the data but the development of the technique is more valuable than the academic and etherial facts collected.

No abstract available.

The Supplement now offered to the Society, is intended to clear up certain points which have been represented to the author as obscure or doubtful in his former communications, and at the same time to connect more intimately the prismatic experiments of the second paper with those made upon convex glasses, and described in the author’s first paper on the subject. Since Dr. Herschel has heard the originality of his observation of the red bow called in question, upon the ground that a red bow had been observed by Sir Isaac Newton, which is merely the converse of the blue bow (the change of colour being dependent upon the direction in which the light is received upon the prism), Dr. Herschel first endeavours to answer the objection, and reminds us that in his former observations the angular breadth and elevation of the two bows are different; but those of the Newtonian blue and red bows are said to be, and are, necessarily equal. In the Newtonian experiment also, the same beam of light is made to exhibit both phenomena, being received upon two right-angled prisms, applied base to base, so that one portion of the light is reflected upwards, as a blue bow from the under surface of the first prism; and the remainder, by transmission, through the second prism, appears as a red bow to an eye beneath. But in Dr. Herschel’s experiment, the same prism is made to exhibit, to an eye in the same situation, the red bow as well as the blue, by means of light transmitted in an opposite direction through the under surface of the prism, without any occasion for a second prism, which (as Dr. Herschel observes) is necessary in the Newtonian method of conducting the experiment.

The second section of Chapter XVI of the Statutes of the Royal Society 'commences with these words: “A catalogue of the manuscripts in the archives shall be available for reference at the rooms of the Society.” Now a catalogue assigning a single number and title to a whole volume or collection of more or less independent documents does not afford much help to the inquirer. However, one detailed catalogue, dealing, item by item, with a large part of the correspondence of the Society, down to the year 1740, was compiled by Mr. W. E. Shuckard, the Librarian, and published in 1840. The arrangement adopted in cataloguing the documents preserved in the 48 “Letter-Books” of this series, was alphabetical for authors, and chronological in the sequence of the contributions of each writer. Parallel with these “Letter-Books,” there exists a set of guard-books, 39 in number, filled mainly with early classified MS. papers of the period 1606—1741. These documents, about 2500 in number, the production of some 800 authors, were catalogued in 1907, a manuscript Calendar being compiled, together with an Introduction and Index Nominum , both since printed. The titles and numbers attached to the several guard-books of this series are here given: it should be noted that the documents had been arranged mainly in accordance with their subjects, but in a few instances by authorship. There has been given to this set the designation- Although some notion of the character and range of these “Classified Papers” may be formed from the titles given to the several books, yet a reference to the MS. Calendar will be required should exact details of any particular paper be wanted. Here the printed Index of Authors’ names will be found useful. Still there are many papers which, being anonymous, cannot be reached in this way. In this connection may be mentioned two long lists of manuscripts in various libraries; these lists are Nos. 32 and 33 in vol. xvii. Of authors’ names in the Index which afford no clue to the subjects of their papers are those of a number of persons concerned in the farming of sea-coals and the trade therein, both at Newcastle and in Scotland. These papers are Nos. 29 to 55 in vol. xxv, and belong to the period 1610—1633. They, and many others dated long before the foundation of the Royal Society, scarcely belong to the Archives, but are interesting in themselves and afford material useful in tracing the antecedents, the scope, and the development of the Society.

Summary-A novel service is proposed to help authors of scientific papers to select journals to which to submit their manuscripts. The aim of the service is to optimize the common interests of authors, readers/users, and science, by providing the authors with a tool for reaching those readers who can most benefit from the news of their accomplishments. The five basic factors which intervene in the choice of a journal are analyzed: relevance, acceptance rate, circulation, prestige and publication lag. With the help of a mathematical model, we show how these five variables can be used in a plausible decision procedure leading to the selection of journals suitable for the publication of given papers. WHEN a scientist submits an article for publication, the choice of a suitable journal is often guided by self-interest. It helps the scientist's career if the results of his work are published in a journal representative of his discipline. It helps most if the journal is the most prestigious in the subject area, with the largest circulation, and with the shortest publication lag. If an author chooses wisely where to publish, this may also serve the interests of the potential readers of his papers. Their concern is to gain valuable information with the minimum possible delay. There is, therefore, a convergence of interests on the part of authors and readers that the proper audience for the reporting of scientific investigations be reached. The healthy growth of the scientific enterpriseand also of enterprises based on the utilization of knowledge-is dependent on the matching of these complementary interests. Some scientists find it difficult to select wisely the journals to which to submit their papers. Scientists who are just starting their careers, who do not have experienced colleagues to advise them, and who do not yet belong to any "invisible college", may experience difficulties. So may scientists who have just switched from one specialty to another, or people who work in interdisciplinary fields or in fields without a welldeveloped "paradigm". Almost any scientist, even the most experienced, has probably felt, at one time or another, that he had submitted some of his papers to the wrong journal or addressed it to the wrong audience. A good service to advise an author on how to reach the readers who can benefit most from news of his accomplishments would be helpful to him, to his potential readers, and to science. To justify such service, one should be able to show that it would fill a real, important and sizeable need, and that it would do as well or better than the advice offered by experienced professional colleagues. Some scientific foundation is required to design such a service with assurance that it will be helpful. Prior work on the sociology of publishing/I-3], on the psychology of authorship/4-5], and on the patterns of communication in a scientific community [6-12] provides the starting point of this study. The "Bradford law" [13-14] states

In essay-type examinations for degrees in British universities, marking customs tend to compress the candidates into a narrow band around the mean. This works especially adversely against those who, in examinations with several papers, achieve excellence in one or more. Often such candidates are awarded only the minimum distinction mark, the effect of which is nullified by aggregation. This is of some consequence in the British system, since the designation of a candidate's examination performance as “First Class,” “Second Class, Upper Division,” etc. is formally made by locating his examination average mark within specified intervals on a percentage scale. Awareness of the possible injustice which this method may cause has given rise to the practice of estimating the “balance of papers,” or considering the “classes” attained by the individual papers in the examination (irrespective of the actual mark), and giving the candidate the benefit of the doubt should he, for example, have a certain number of papers in a class higher than that indicated by his examination average. A classification reached in this way may of course be at variance with that indicated by the candidate's average of marks, and thus introduce an arbitrary element. An alternative method is therefore proposed in this paper. The usual custom is to assume that the marks indicating the various classes should be the same for the degree as a whole and for the individual papers. It would seem preferable first to determine the balance of papers which would be accepted as a claim to a First Class degree (since it is unlikely that a candidate writing several papers will be able to attain a first class mark in all) and deduce therefrom the classification intervals for the individual papers. A method of doing so is elaborated.

A dual-fuel engine may be defined as a compression-ignition engine using mainly gaseous fuel but with a small quantity of fuel oil injected as an ignition source; the engine can be changed over instantaneously and under load to operate on liquid fuel alone. The recent availability of natural gas in this country once again attracts the attention of engineers towards gas as a fuel for internal-combustion engines. This paper traces the development of dual-fuel engines, originally using sewage gas and more recently using natural gas, and considers their advantages, both technical and economic, compared with spark-ignited and diesel engines. The dual-fuel engines within the authors' experience are described. The critical factors in handling natural gas in its liquid form are considered, and the extended scope of dual-fuel engines and alternative fuel engines in mobile applications is briefly reviewed. Finally, the paper examines the future for dual-fuel engines and suggests directions in which further development is required.

This paper discusses the pump output problems peculiar to power assisted steering, together with the need for the flow control valve. A description of a basic combined flow control and pressure relief valve is given, and the adaptation of the flow control valve to the requirements of power assisted steering is detailed. The pump construction and operation are mentioned, with a description of a typical pump with reference to the special features incorporated for quiet operation. Some changes in design, in an attempt to keep pace with higher pressure demands, are described. The paper also presents the various types of installations and measures adopted to minimize transmitted noise, and concludes with a brief survey of pump types.

The second paper assesses the overall performance characteristics of the differential compound engine (d.c.e.) first reported in (21), designed to constitute an integrated engine-transmission system providing high unit output, combined with outstanding torque characteristics for traction applications. Experimental results, for both equilibrium conditions and transient response are presented for the original two-stroke c.i. version of the laboratory unit, incorporating the Rootes TS 3 opposed piston engine. Theoretical predictions both for this version, and the later four-stroke version, using the Perkins 6·354 engine, based on the generalized computer approach of the first paper, are also presented. The unit is then critically compared with existing or prospective traction prime movers using the following criteria. (1) Fuel economy. (2) Torque characteristics. (3) Noise and emission. (4) Unit specific weight and bulk. Finally, a projected automotive unit of approximately 2 hp shaft output is described with illustrations to show the potential of the d.c.e. as an alternative engine-transmission system for heavy trucks and off-highway vehicles.

The porous-block system of stabilization processing Autopositive paper was introduced some eight years ago, and was superseded by small motor-driven machines using a two-bath immersion system. With the aim of increasing the processing rate and simplifying the processing machines so that very lightweight papers could be handled, experimental monobaths were evolved. These gave promising results, but the monobath was eventually abandoned in favour of a two-solution system with surface-application processing. With such a system a processing rate of lO ft/min has been achieved, using a high pH developer, and a stabilizer based on thiocyanate. The tendency for thiocyanate to attack the silver image on keeping the processed print has been overcome by the use of chemical inhibitors in conjunction with a surface-application processing technique. The design of the processing machine makes use of the natural curl of the wetted paper to prevent wrap around the rollers, very light-weight papers being handled w...

The development of implement control systems has been greatly influenced by the pattern set by the Te20 Ferguson tractor, and most three-point linkage draught control systems operate on the same principle. Such designs, whilst adequate for most purposes on level going, display poor depth control behaviour when traversing undulating ground. A full understanding of these systems has been limited by the absence of a mathematical theory capable of predicting their behaviour. This paper sets out to examine the problem in control theory terms. An experimental hydraulic control system has been built using pure draught force sensing, and its behaviour has been studied both mathematically and experimentally in the laboratory and in the field. To enable theoretical predictions of system behaviour to be made a second rig was constructed to study the transfer functions of implements. This rig can also serve as a simulator of field surface disturbances. The performance of the experimental system was compared with a popular commercial system using the second rig as a simulator and the results indicate that pure draught control sensing as used in the experimental system is feasible in practice. The paper concludes with a short discussion of alternative control strategies.

This paper refers to the wide range of commodities now carried by the railways and deals in particular with those handling problems which require consideration. The development of bulk handling in trains of largest size and operating between fixed points has permitted considerable advance in modern handling techniques, particularly in loading and unloading of the materials carried. Bulk transport of cars and car bodies is also extending rapidly. The alternative methods of handling containers and the problems facing the railways in catering for home transport and yet being compatible with other forms of transport are referred to. European and world practices in the field of ‘containerization’ are included, and the paper is illustrated with a number of photographs and drawings.