Amount Of Additional Material Research Articles

A level set based method for fixing overhangs in 3D printing

3D printers based on the additive manufacturing technology create objects layer-by-layer dropping fused material. As a consequence, strong overhangs cannot be printed because the new-come material does not find a suitable support over the last deposed layer. In these cases, one can add support structures (scaffolds) which make the object printable, to be removed at the end. In this paper, we propose a level set based method to create object-dependent support structures, specifically conceived to reduce both the amount of additional material and the printing time. We also review some open problems about 3D printing which can be of interests for the mathematical community.

STRAIN ENERGY ASSOCIATED WITH STRUCTURAL MODIFICATIONS

Modifications to linear elastic structures are considered for which the amount of additional stiffening material is increased proportionally. It is proved that, for fixed loading, the strain energy will not be increased and, for fixed displacements, the strain energy will not be decreased by the addition. Furthermore the graphs of strain energy versus the amount of additional material will be monotonic. Also the strain energy absorbed by an incremental amount of additional material must equal the change in the total strain energy for both the cases of fixed loading and fixed displacements. These behavioural properties have been formulated as three theorems. The paper justifies and discusses these and presents some simple illustrations.

Acoustic emission produced by the delta-to-alpha phase transformation in Pu-Ga alloys

Detailed measurements are reported of acoustic emission (AE) produced during theδ → α phase transformation in plutonium-gallium alloys. During thermal cycling, the number of AE signals produced decreased with each thermal cycle more rapidly than the amount of additional material transformed. Thus, some portion of the transformation does not produce detectable AE. The average amplitude of the signals produced during quenching was not appreciably dependent on gallium content or cooling cycle. The amplitude of the signals is greater for rapid cooling than for slow cooling. The AE behavior is consistent with an isothermal, nonthermoelastic martensitic transformation.

Words and Deeds: The Action of Covenant in the Reign of Edward I

The action of covenant before the reign of Edward III is a subject of considerable mystery. By the time that the Year Books come to the fore in the last decade of the thirteenth century, it has become a relatively scarce form of action in the royal courts, and consequently our sources of information are fairly scanty; in addition, by this time, the restrictions which limited the potential of covenant as a general contractual remedy are already firmly in evidence, with the result that the development of these restrictions is not easily visible. There is, though, a considerable amount of additional material in the rolls of the Justices in Eyre in the reign of Edward I, and in some of the multifarious tracts on pleading which proliferated in the later years of the thirteenth century and which have remained for the most part in manuscripts which have not been systematically examined by legal historians.

Kaldor's ‘the military in development’ — a comment

Mary Kaldor's article is a tour de fbrce in its attempt to explore 'The military in development ' (World Development, June 1976). She implies that a fresh approach is necessary since those of modernization theorists and Marxists 1 'both fail to explain the differences in the behaviour of military institutions in Third World countries'. The former, in Kaldor's view, 'have explained the military's political tendencies by reference to inherent institutional characteristics sometimes making confusing use of the term 'class', and they have explained the military's economic impact in terms of direct absorption or mobilization of resources'. Marxists, in contrast, 'have treated the military as a more or less neutral instrument of the ruling class and looked at the economic impact of the military in terms of its role in preserving a social system characterized by a particular allocation of resources'. According to Kaldor, 'very little has been written about the role of the military in the process of historical change from a Marxist perspective'. She sets out to reconstruct Marxist theory, therefore, from a limited number of sources: Karl Liebknecht's Militarism and Anti-Militarism; Engels' Origin of the Family, Private Property and the State (from which she quotes a single line to illustrate Engels' technological determinism); Marx's Eighteenth Brumaire o¢ Louis Bonaparte; and recent papers by a Marxist study collective in Hamburg, which see the role of the military in the world-wide allocation of resources 'as a mechanism for extracting surplus product in the periphery in order to support capitalist accumulation in the metropolis' . Kaldor ignores a considerable amount of additional material, particularly by Engels, which ought not to be neglected in setting out the classical Marxist position. Three chapters in Anti-Duhring entitled 'The force theory' and an unfinished study which applies this theory to Bismarck's policy of 'Blood and Iron', entitled The Role o f Force in History (first translated into English in 1968) are directly concerned with the application of force in the course of economic development. A brief summary of these and other works, as well as some of Marx and Engels correspondence, will suggest why Marxists have treated the military 'as a more or less neutral institution of the ruling class'. Kaldor's objections to such a treatment appear to be misinformed. Her rendering of the Marxist position suffers as a consequence. So, too, does her attempt at what appears to be an arbitration of the Marxist and 'modernization' positions. When it becomes clearer why Marxists have treated the military as a neutral instrument of the ruling class it becomes clearer why the Marxist approach may best facilitate theorizing about the military in development. Kaldor is also concerned with the role of the military in the allocation of resources and with the impact of Western-type weapons systems in underdeveloped countries. Our comments on this theme question both her conclusion of a 'strong association' between high military spending and high rates of industrial growth in light of the evidence, and how great a positive impact on industrialization the permanent arms economy might reasonably be expected to have.

The Concise Oxford Dictionary of French Literature

A revised and condensed version of the Companion, including a considerable amount of additional material.

Involvement of chromosomes 8, 9, 19 and 22 in PH1 positive and PH1 negative chronic myelocytic leukemia in the chronic or blastic stage.

Abstract. Chromosome 9 had additional chromosomal material at the end of the long arm in 15 of 16 patients with Ph1 positive CML. The remaining patient had a normal chromosome 9but additional material on 19. The amount of additional material was approximately the same as that lacking on chromosome 22. Translocations between 9 and 22, and 19 and 22, respectively, are therefore suggested. One patient with Ph1 negative CML had no detectable additional chromosomal material on any chromosome including chromosome 9, which gives further support to the view that there is indeed a translocation in Ph1 positive patients. Extra chromosomes appeared in two of three Ph1 positive patients in the blastic stage. Both patients had extra number 8 chromosomes and double Ph1, and one patient had further extra chromosomes, i.e. 7, 11, 12, 16, 17 and 19.

Letter: A new consistent chromosomal abnormality in chronic myelogenous leukaemia identified by quinacrine fluorescence and Giemsa staining.

CELLS from nine consecutive patients with chronic myelogenous leukaemia (CML) have been analysed with quinacrine fluorescence and various Giemsa staining techniques. The Philadelphia (Ph1) chromosome in all nine patients represents a deletion of the long arm of chromosome 22 (22q−)1,2. An unsuspected abnormality in all cells from the nine patients has been detected with these new staining techniques. It consists of the addition of dully fluorescing material to the end of the long arm of one chromosome 9 (9q+). In Giemsa-stained preparations, this material appears as an additional faint terminal band in one chromosome 9. The amount of additional material is approximately equal to the amount missing from the Ph1 (22q−) chromosome, suggesting that there may be a hitherto undetected translocation between the long arm of 22 and the long arm of 9, producing the 9q+ chromosome.

Additional Notes on the Tabanidae of Panama1 (Diptera)

In 1942 I listed (Ann. Ent. Soc. Amer., 35, No. 4, p. 471) the 89 species of Tabanidae then known from the Republic of Panama and the Canal Zone. Since that time a certain amount of additional material has accumulated which makes it seem advisable to publish the present additional note. Nine species are added to the Panama fauna, six of which are described as new, bringing the total species recorded to 98. The heretofore unknown males of several species are described, and additional material and extension of ranges of a number of hitherto poorly known species are recorded.

The Larval Stages of processa canaliculata Leach

The material upon which the following account of the development of P.canaliculata is based was mainly obtained in 1902 when working in the Laboratory at Plymouth. The larvæ were first noticed, and their identity suspected, in April of that year, and identification was made certain by keeping the larvæ in the “mysis” stage until they moulted into the post-larval form, some individuals being kept also through several subsequent moults. The intermediate stages were all taken from the plankton, since I was unable to hatch the larvæ from the egg. The only egg-bearing female seen at that time was taken on the Eddystone Ground on April 29, and her eggs were so far advanced that, although she was unfortunately killed, a few larvæ escaped from the eggs and made it possible to obtain some idea of the structure of the first zoæa.During a short stay in Plymouth during April, 1922,1 was able not only to pick out a few more specimens from the plankton then brought in, but also, by working through a large number of preserved plankton samples, to obtain a considerable amount of additional material, mainly of later stages. A few specimens have also been found in samples of plankton from the North Sea preserved at the Fisheries Laboratory at Lowestoft, for the loan of which I am indebted to Mr. A. C. Hardy. But the larvæ of this species are much rarer in the North Sea than in the neighbourhood of Plymouth, where they are quite common.

Mosquito Notes.—IV

The intersting collection of Culicine mosquitos on which these notes are based was made during 1922 by Dr. H. P. Hacker, of the Malaria Bureau, Kuala Lumpur, Federated Malay States. Most of the material was obtained during an expedition to Cameron's Highlands, on the main range near Tapah, in September. A small amount of additional material from Ulu Gombak also yielded some specimens of interest.

The Boulders of the Travellers' Rest Gravel Pit, Cambridge

ABOUT twelve years ago Dr. R. H. Rastall and Mr. J. Romanes published an account of the Boulders of the Cambridge Drift. In this paper a list was given of the rock-types recognized at that time in the gravels of the Travellers' Rest Pit, situated about a mile north-west of the town of Cambridge on the Huntingdon Road. Since that time Professor Marr has paid much attention to this pit, among others, with special reference to the Palæolithic implements there found. He has embodied his results in two important papers. In the course of this work Professor Marr collected a number of interesting erratics, and the same pit has also been investigated by many geologists connected with the University, both members of the Sedgwick Club and others. During the last ten years, though the North Pit has been abandoned, the South Pit has been very actively worked for gravel, and has been greatly increased in size. In consequence of this a large amount of additional material has been collected, including many new types, while some of the older specimens, whose origin had been left indeterminate by Rastall and Romanes, have been now identified. Hence it is felt that the time has now arrived when these more recent results should be put on record.

IV.—The Gametophyte Generation of the Psilotaceæ

Since the preliminary announcement of the discovery of the prothalli of Tmesipteris and Psilotum communicated to the Royal Society of Edinburgh in June 1916, a considerable amount of additional material has been found, and it seems therefore desirable to place on record a more detailed account of these interesting structures. The preliminary description, as published, was based upon but a few specimens, and these were not sufficient to reveal all of the vegetative and reproductive features, nor enough to justify any broad general conclusions as to the phylogenetic position of the Psilotaceæ. The discoyery, however, has filled in an important and interesting gap in our knowledge; for the Psilotaceæ are the very last of the known Pteridophytes to surrender their gametophytes to the light of science.

IX. On fossil plants, showing structure, from the base of the waverley shale of Kentucky

A large part of the material upon which the present memoir is based was derived from Prof. Charles Eastman, now of the University of Pittsburg but formerly of the staff of the Agassiz Museum of Harvard University. It was presented by him to the junior author. A considerable amount of additional material, some of it of the greatest interest, including, among other things, a Lepidodendrid cone, was purchased by the junior contributor to the present article, from Mr. Moritz Fischer, of Cincinnati, Ohio, who was associated with Prof. Eastman as a collector in his work on the deposits containing the fossil plants here described. The locality and horizon of the fossil plants under consideration are described as follows by Prof. Eastman in a letter to the junior author: “The collection of fossiliferous nodules, which I turned over to you, was obtained by myself in company with Mr. Moritz Fischer, of Cincinnati, at a locality about one mile west of Junction City in Boyle County, Kentucky, in the spring of 1906. The nodule layer is a well-marked stratum 20 to 24 inches thick, lying at the base of the Waverley (Lower Carboniferous) and immediately above the Genessee Black Shale of Upper Devonian age. The accompanying fish remains are regarded by myself and Dr. Bashford Dean, who have described some of them, as indicating Lower Carboniferous age.”

A Text-book of Organic Chemistry

THE new issue of Bernthsen's text-book, which has been edited and revised by Prof. Sudborough, is a great advance on former editions. Although the general arrangement of the contents has been preserved, the amount of additional material has so much extended the scope of the original work that, in its present form, it is practically a new book. Some of the more prominent alterations and additions may be briefly noticed. In the first place, there are frequent references to physical chemistry and its application to problems of organic chemistry which are interesting and suggestive. Secondly, more than 100 additional pages at the end of the book are devoted to topics which have undergone recent development, such as the alkaloids, the terpenes, resins, glucosides, and proteins; there is a section on reagents, a section on stereochemistry, and one on physical constants in relation to structure. Though highly condensed, they are clear and explicit, and are furnished with full and useful references (which, by the way, would be more convenient and less disturbing to the reader at the foot of the page than embodied in the text). Finally, the system of nomenclature has been modernised The term “atomic,” applied to alcohols, phenols, &c., has been replaced by “hydric”; “ether,” used in connection with organic salts, becomes “ester”; “alcohol radical” is changed to “alkyl,” and the word “radical” is properly spelt. The editor seems to have been in doubt about isomer and isomeride, and oxy and hydroxy, which are used indiscriminately. The writer entirely sympathises with this uncertainty in the use of certain terms, for the chemist often finds himself awkwardly placed. Not only does he feel obliged to respect the nomenclature adopted by foreign chemists, which is not always happily chosen, but he must conform in some measure to the system laid down by the Chemical Society. The purine derivatives offer a case in point. A Text-book of Organic Chemistry. A. Bernthsen. Edited and revised up to date by Dr. J. J. Sudborough. Pp. xvi + 658. (London: Blackie and Son, Ltd., 1906.)