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Article
Publication date: 15 August 2016

Brian Torries, Amanda J. Sterling, Nima Shamsaei, Scott M. Thompson and Steve R. Daniewicz

The purpose of this study is to calibrate a microstructure-based fatigue model for its use in predicting fatigue life of additively manufactured (AM) Ti-6Al-4V. Fatigue models…

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Abstract

Purpose

The purpose of this study is to calibrate a microstructure-based fatigue model for its use in predicting fatigue life of additively manufactured (AM) Ti-6Al-4V. Fatigue models that are capable of better predicting the fatigue behavior of AM metals is required to further the adoption of such metals by various industries. The trustworthiness of AM metallic material is not well characterized, and fatigue models that consider unique microstructure and porosity inherent to AM parts are needed.

Design/methodology/approach

Various Ti-6Al-4V samples were additively manufactured using Laser Engineered Net Shaping (LENS), a direct laser deposition method. The porosity within the LENS samples, as well as their subsequent heat treatment, was varied to determine the effects of microstructure and defects on fatigue life. The as-built and heat-treated LENS samples, together with wrought Ti-6Al-4V samples, underwent fatigue testing and microstructure and fractographic inspection. The collected microstructure/defect statistics were used for calibrating a microstructure-sensitive fatigue model.

Findings

Fatigue lives of the LENS Ti-6Al-4V samples were found to be consistently less than those of the wrought Ti-6Al-4V samples, and this is attributed to the presence of pores/defects within the LENS material. Results further indicate that LENS Ti-6Al-4V fatigue lives, as predicted by the used microstructure-sensitive fatigue model, are in close agreement with experimental results. The used model could predict upper and lower prediction bounds based on defect statistics. All the fatigue data were found to be within the bounds predicted by the microstructure-sensitive fatigue model.

Research limitations/implications

To further test the utility of microstructure-sensitive fatigue models for predicting fatigue life of AM samples, future studies on additional material types, additive manufacturing processes and heat treatments should be conducted.

Originality/value

This study shows the utility of a microstructure-sensitive fatigue model for use in predicting the fatigue life of LENS Ti-6Al-4V with various levels of porosity and while in a heat-treated condition.

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Article
Publication date: 1 February 1968

The initial shock of devaluing the currency, after so many promises that it would not take place, has passed; only the uncertainty and apprehension remain. It seems an idle…

137

Abstract

The initial shock of devaluing the currency, after so many promises that it would not take place, has passed; only the uncertainty and apprehension remain. It seems an idle exercise to compare the present state of the country's economy with other periods in recent history, such as when in the first Labour Government, we went off the gold standard; at that time, shock was indeed profound and again, the French were cock‐a‐hoop, but the position was complicated by the huge inter‐indebtedness of the Allies in the First War. Or the first devaluation after the Second World War, but both periods were also characterized by public waste and profligate spending. Now, we have to obtain foreign loans and financial backing to keep going, and it is this aspect of the present devaluation which will probably far outweigh any positive advantages. The country's massive external debts were increased by approximately one‐seventh overnight, probably wiping out completely all the repayments made at such great effort since the War. Devaluation of the currency cannot be seen as anything but a grievous blow to the country, presaging hard times ahead for everyone. When promises were being made that devaluation would not take place, there can be little doubt that these were honestly made and, at the time, believed in, for no Government of a country with imports always exceeding exports, would impose such a burden on its people willingly. It must then have been forced upon them.

Details

British Food Journal, vol. 70 no. 2
Type: Research Article
ISSN: 0007-070X

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Publication date: 1 April 1968

We can think of those with a cynical turn of mind who might consider not a little of the present output of the parliamentary machine as “harem scarem” law, but the indecent haste…

130

Abstract

We can think of those with a cynical turn of mind who might consider not a little of the present output of the parliamentary machine as “harem scarem” law, but the indecent haste, the freak urgency of some politically inspired laws apart, it is only too obvious that law is being made under rush conditions, and the reasons are not far to seek. A hectic, over‐active party executive, feverishly pushing ahead with its policies produces impossible working conditions for the parliamentary draftsmen. Law, whether it is statute or regulation, has never been more complex than it is today; time allowed for parliamentary debate is completely inadequate; too many and varied interests have to be taken into account, to say nothing of the vast range of delegated legislation. The urgency of some legislation is doubtful; it is difficult to see the need for all the hurry; a little more time in proper debate would prevent some of the loopholes which subsequently appear and render the law more comprehensible; incomprehensibility and justice are rarely compatible. As Diplock L J., said in the Court of Appeal in Rex. v. Industrial Injuries Commissioner ex parte Cable (1968) 1 A.E.R., 9, a few months ago—“Judges have been at their wits' end to know what some of the provisions mean. It would be a good thing if time could be found to remedy the blemishes.”

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British Food Journal, vol. 70 no. 4
Type: Research Article
ISSN: 0007-070X

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Publication date: 1 June 1982

Another Christmas month is upon us, following it seems quickly on others that have been. Such is the relativity of Time, it is not yesteryear, but could be yester‐month or even…

252

Abstract

Another Christmas month is upon us, following it seems quickly on others that have been. Such is the relativity of Time, it is not yesteryear, but could be yester‐month or even yester‐week. The seasons pass like youth, all too soon. Our minds return to other Christmas months of yore — “Memories are like Christmas roses!”, the old saying goes. The children, singing much‐loved hymns and carols, happy family settings, a birth, christening, so much to look forward to in the new year. There are not always such happy memories, but memories just the same — Christmas in war‐time, Earth's joys growing dimmer each year, change and decay, life drawing to a close for many a soul; old folk tend to see Christmas as a time of passing, of leaving the world behind.

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British Food Journal, vol. 84 no. 6
Type: Research Article
ISSN: 0007-070X

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Article
Publication date: 1 October 1918

The National News publishes the following :—

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Abstract

The National News publishes the following :—

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British Food Journal, vol. 20 no. 10
Type: Research Article
ISSN: 0007-070X

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Publication date: 1 February 1966

The succession of storms around the question of the disposal of the large quantities of corned beef called in or held up from the time of the Aberdeen Typhoid Epidemic can have…

31

Abstract

The succession of storms around the question of the disposal of the large quantities of corned beef called in or held up from the time of the Aberdeen Typhoid Epidemic can have done little to enhance the image of public administration. There was a profusion of statements, official and otherwise, and what seemed to be a fight between factions in the trade, with the position of the two Ministries involved none too clear; all this was thrown into a thorough ferment by political intervention by the Prime Minister himself. There can never have been anything quite like it in any branch of public health, not so much in what has been done, but in the way it was done.

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British Food Journal, vol. 68 no. 2
Type: Research Article
ISSN: 0007-070X

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Article
Publication date: 1 May 1973

The pattern of prosecutions forfood offences has changed very little in the past decade. Compositional offences have rarely exceeded 5 per cent and, since the 1967 batch of…

111

Abstract

The pattern of prosecutions forfood offences has changed very little in the past decade. Compositional offences have rarely exceeded 5 per cent and, since the 1967 batch of regulations for meat products, are mostly in respect of deficient meat content. Food hygiene offences have also remained steady, with no improvement to show for all the effort to change the monotony of repulsive detail. The two major causes of all legal proceedings, constituting about 90 per cent of all cases—the presence of foreign matter and sale of mouldy food—continue unchanged; and at about the same levels, viz. an average of 55 per cent of the total for foreign matter and 35 per cent for mouldy food. What is highly significant about this changed concept of food and drugs administration is that almost all prosecutions now arise from consumer complaint. The number for adulteration as revealed by official sampling and analysis and from direct inspectorial action is small in relation to the whole. A few mouldy food offences are included in prosecutions for infringements of the food hygiene regulations, but for most of the years for which statistics have been gathered by the BFJ and published annually, all prosecutions for the presence of foreign matter have come from consumer complaint. The extent to which food law administration is dependent upon this source is shown by the fact that 97 per cent of all prosecutions in 1971 for foreign bodies and mouldy food—579 and 340 respectively—resulted from complaints; and in 1972, 98 per cent of prosecutions resulted from the same source in respect of 597 for foreign matter and 341 for mouldy food. Dirty milk bottle cases in both years all arose from consumer complaint; 41 and 37 respectively.

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British Food Journal, vol. 75 no. 5
Type: Research Article
ISSN: 0007-070X

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Publication date: 1 August 1960

A case which because of its far‐reaching implications attracted considerable interest (see report on p. 91) was recently heard at Highgate. It was alleged that ice lollies were…

46

Abstract

A case which because of its far‐reaching implications attracted considerable interest (see report on p. 91) was recently heard at Highgate. It was alleged that ice lollies were “unfit for human consumption” because of the temperature at which they were sold. Because the lollies were too cold, one stuck to a boy's lips and chin and another to a boy's tongue, peeling off skin when they were removed. The prosecution's case was that on the evidence, the vendors should be convicted of selling food unfit for human consumption, but the magistrates did not accept this contention and dismissed the case. The mishap was an unfortunate one, and Counsel's submissions for the defence notwith‐standing, it is difficult to see how the case could have been decided otherwise. There was never any suggestion of inferior ingredients being used in the manufacture of the lollies.

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British Food Journal, vol. 62 no. 8
Type: Research Article
ISSN: 0007-070X

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Article
Publication date: 1 June 1978

Application of the numerical method to the art of Medicine was regarded not as a “trivial ingenuity” but “an important stage in its development”; thus proclaimed Professor…

196

Abstract

Application of the numerical method to the art of Medicine was regarded not as a “trivial ingenuity” but “an important stage in its development”; thus proclaimed Professor Bradford Hill, accepted as the father of medical statistics, a study still largely unintelligible to the mass of medical practitioners. The need for Statistics is the elucidation of the effects of multiple causes; this represents the essence of the statistical method and is most commendable. Conclusions reached empirically under statistical scrutiny have mistakes and fallacies exposed. Numerical methods of analysis, the mathematical approach, reveals data relating to factors in an investigation, which might be missed in empirical observation, and by means of a figure states their significance in the whole. A simplified example is the numerical analysis of food poisoning, which alone determines the commonest causative organisms, the commonest food vehicles and the organisms which affect different foods, as well as changes in the pattern, e.g., the rising incidence of S. agona and the increase of turkey (and the occasions on which it is served, such as Christmas parties), as a food poisoning vehicle. The information data enables preventive measures to be taken. The ever‐widening fields of Medicine literally teem with such situations, where complexities are unravelled and the true significance of the many factors are established. Almost every sphere of human activity can be similarly measured. Apart from errors of sampling, problems seem fewer and controversy less with technical methods of analysis then on the presentation and interpretation of figures, or as Bradford Hill states “on the application of common sense and on elementary rules of logic”.

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British Food Journal, vol. 80 no. 6
Type: Research Article
ISSN: 0007-070X

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Article
Publication date: 1 November 1951

Food manufacturers, as well as Food and Drugs Authorities, are greatly perturbed at the. immense increase of foreign bodies which find their way into food sold or on sale to the…

32

Abstract

Food manufacturers, as well as Food and Drugs Authorities, are greatly perturbed at the. immense increase of foreign bodies which find their way into food sold or on sale to the public. In an attempt to analyse these occurrences one feels that a useful purpose would be served if they were subdivided into two main headings. The first, and probably the most common, is the foreign body or article associated in some way with the packing or manufacturing of the article; secondly, that which not only taints the surrounding portion of the food but for which there is decidedly less justification for its presence. The chief offenders in this respect are tobacco and portions of rodent and insect bodies and excrement. An attempt at consumption of a nail or ferrous metal may result in some discomfort or injury to the person concerned, but the majority of people would prefer this risk to the shock of finding that they have eaten half a cockroach or the tail of a mouse. Under the first heading one finds such things as nails, screws, portions of paper and stones found in bread and confectionery. A large proportion of these could be removed by careful sifting of the bulk article, although bulk compound cooking fat, from which articles have been collected, presents many difficulties in this respect. Some manufacturers, in order to reduce the risk to the minimum, have installed magnetic detectors to pick up bits of ferrous metals which may be present. These, however, apart from their expense, have not proved very successful in the case of fats. It is necessary for the manufacturer to keep a constant check on his equipment and storage bins. Screws and nails have been found in bread, and, when taken back to the bakery, they have been found to fit exactly some part of the equipment. In these circumstances it has been obvious that regular maintenance would have prevented most of these unfortunate occurrences. A Court case may not only prove costly but the effects would make themselves felt in the annual turnover. In these cases, such as the more common one of glass being found in milk bottles, the management are entirely dependent upon the human element. Accidents do occur in the most perfect of milk bottling machines. Irrespective of how much one would like to boast that the product is untouched by hand, one cannot dispense with the keen scrutiny that is required, not only in removing heavily contaminated bottles, which may have held paint or other similar substances, from being fed to the machine, but at the other end as they roll off the conveyor. The question of cigarette ends, portions of matches and specks of tobacco brings to the forefront the well debated question of “ Should smoking be allowed in food preparation premises?” The report of the Manufactured Meat Products Working Party, 1950, under the heading “ Use of Tobacco ”, states: “ We consider it undesirable for anyone to smoke or chew tobacco or use snuff while in rooms used for the preparation of meat products or the storage of raw materials or the finished product. The use of tobacco in any form is likely to lead to unhygienic practices and to the contamination of food. We recommend, therefore, that the use of tobacco in rooms used for the preparation or storage of raw material or meat products should be prohibited by regulation.” It will occur to many that, where regulations have been made and the “ No Smoking ” rules strictly enforced, cases still occur of cigarette ends being found in the finished product, as the following case will illustrate. A partly‐used carton of sugar was brought into the office of a Food and Drugs Authority in which was found the stub end of a cigarette, which, from its appearance, had been flung into the manufactured sugar immediately after use, for the smoking end was encrusted with sugar. The matter was taken up with the packers, and it was explained to them that neither the man, wife or son in the household concerned were smokers. In the factory the non‐smoking rule was rigidly enforced, but it was found through the code number on the carton that, at the time, building contractors were working in and around the factory. In the case of a cigarette end in a packet of “ chocolate sweet tobacco ” some amusement was created at getting the real thing in a packet of sweets. It was, however, a serious matter for the firm concerned, who pleaded guilty, and in their defence it was stated that there were more than twenty non‐smoking notices on the premises and the occurrence was inexplicable to them. A perusal of the most recent cases resulting in convictions show that cigarette ends have been found in substances varying from bread, bread‐rolls, almond slices and buns to sweets, and in the majority of cases the non‐smoking rule was strictly enforced; it would, therefore, seem that, having taken every precaution, the manufacturers are compelled to regard this as one of the hazards to be encountered in the trade. It is felt that in the second group of foreign bodies, rodent and insect bodies and excrement are by far the most serious. The contamination of food by such filth is invariably indicative of the state of the premises where the food was prepared or sold. The public must be protected from such filth and the grave risk of food infection which exists where insects or rodent infestations occur in food preparation or storage premises. Confirmation of this can be found in an analysis of the cases published in this Journal. These illustrate clearly that, where action has been taken with regard to the premises in this respect, attention was initially directed by contaminated food being sold. Even with old premises there is no excuse for infestation by insects such as cockroaches, flies or rodents. Modern residual insecticides, if used selectively, will not only control but eradicate the former. The Local Authority Pests Operators, or the specific rodent exterminating firms, will deal quite effectively with the latter, although some constructive rat‐proofing may have to be carried out in addition. It will be seen from the brief outline given above that many difficulties exist in dealing with the problem of foreign bodies in food, and manufacturers who take the fullest precautions have the sympathy of the Food and Drugs officials when single occurrences spoil an otherwise excellent record. Few take action in such cases, realising the fallibility of the human element. Unfortunately many convictions still occur in this sphere which could have been avoided by attention to hygienic practices, strict supervision and the education of workers employed.

Details

British Food Journal, vol. 53 no. 11
Type: Research Article
ISSN: 0007-070X

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