E. Skerry and L.W. Hicks
THE purpose of this article is to describe two methods, which may be employed independently of chemical analysis and within their limitations, to classify steels.
It will take some time before the value of the recent Production Exhibition held in London can be fully assessed, but there is little doubt that this new departure in exhibitions…
We have pleasure in acknowledging the courtesy of the Public Health Authorities of the State of Queensland, Australia, for sending us this record. Want of space compels briefness…
Abstract
We have pleasure in acknowledging the courtesy of the Public Health Authorities of the State of Queensland, Australia, for sending us this record. Want of space compels briefness, but we hope that the few points to which we have drawn notice may prove of interest to readers. We are concerned with the work of the Government Chemical Laboratory and local authorities so far as that relates to the purity, storage, and handling of the food supply. Action is taken under the Food and Drug sections of the Health Acts, and Regulations connected therewith. The difficulties naturally arising in the administration of a vast and sparsely populated tropical territory have been increased, there as here, by shortage of labour and materials of all kinds. So that schemes devised by local authorities in the interests of public health have in many instances been seriously delayed. The Chief of the Government Chemical Laboratory remarks that the Department has worked under incessant pressure for many years. “ The well informed, versatile and competent practitioners ” demanded by the service are not at present available outside the Government service, and “ unless they are forthcoming from time to time to rejuvenate the staff the laboratory may be reduced to a laboratory of professional labourers.”
Not very long ago H.M. Government plastered walls and hoardings with a large scale portrait of a haggard woman in deep mourning surmounted by the words “ Keep Death Off the Roads…
Abstract
Not very long ago H.M. Government plastered walls and hoardings with a large scale portrait of a haggard woman in deep mourning surmounted by the words “ Keep Death Off the Roads ”. A solemn warning for the rising toll taken of human life through the carelessness of others. It seems strange that no similar publicity is vouchsafed to the number of deaths caused through food poisoning. Figures recently quoted give these as five thousand a year. The Central Council for Health Education set the ball rolling in 1947 when they held a one‐day conference on food and drink infections which was attended by representatives of all branches of the food industry and of local authorities in England, Wales, and Northern Ireland. Advocating the instruction of managements, food handlers, and housewives, Dr. Robert Sutherland, Medical Adviser and Secretary to the Central Council, explained that the purpose of the conference was to get local authorities to start a campaign in their own area to encourage the food handler to become conscious of his responsibilities. Posters, leaflets, film strips, lecture syllabuses were all to be made available, and this looked like a step in the right direction. Guildford, Surrey, perhaps as a result of this conference, staged a campaign for cleaner food last March. They issued pamphlets, demonstrated likely hiding places for germs, and bestowed certificates upon those shops and premises agreeing to a certain standard in the preparation of food. (An article by the M.O.H., Guildford, in last month's issue, on page 122, described this campaign.) More recently, the Mayor of Lambeth has been saying much on the subject of hygiene; he even attributes some cases of food poisoning to the nail varnish adorning the fingers of waitresses. This is perhaps carrying things a little too far, but the Mayor rightly pounces on the dangers of hidden bacteria in cracked china. Much controversy has been waged on whether or not cracked cups are a potential source of infection. A writer in a recent issue of The Municipal Journal discounts this theory and says that the risk of anyone acquiring infection from a cup or glass with a chip in it is so remote as to be not worth considering. Having dismissed the danger so lightly, he goes on to say that the cracked and chipped utensil is really only disliked because something that is clean and pleasant to look at is preferred. This, no doubt, is true, but the warnings, supported by test results, given and made by Dr. Sidney Linfoot and published in The Lancet in 1945 cannot be disregarded. That these dangers are very real was demonstrated by the results of a bacteriological examination of twenty cups obtained from different public restaurants in which the microorganisms obtained from cultures from the cracks in each of the cups were enumerated. In many cases there was a free growth of Staph. aureus and also haemolytic streptococcus. There was also a fairly frequent appearance of intestinal organisms (B. coli, B. proteus, etc.) and one cup gave a heavy growth of Friedlander's bacillus. Nearly all the organisms found were such as are commonly associated with stomatitis and mouth and gum complaints generally. Dr. Linfoot further suggested that the presence of Friedlander's bacillus was also an indication that respiratory organisms might be a source of infection and that it was reasonable to assume that the Klebs‐Loeffler bacillus might be found if the cups had been used by a carrier. The presence of haemolytic streptococci is also a reminder that a cracked cup may be an agent in the spread of scarlet fever. Syphilitic infection is unlikely but not impossible, and in the same category falls tuberculosis. These organisms, particularly the former, would be difficult to discover from cracks, but the fact that even relatively easily killed organisms can be found alive in such sites suggests that their transmission is not impossible. The most obvious danger, states Dr. Linfoot, is that of ulcerative stomatitis. Education of the public, always a little dubious about the existence of microbes, would mean expensive advertising campaigns; legislation would help, but there are doubts as to whether or not it could be enforced. According to the Ministry of Food, Dr. Edith Summerskill is already busy drawing up a list of by‐laws for submission to local authorities with a code of practice applicable to every trade. This is useful, but in no way sufficient to tackle the problem. It has been suggested that much could be done by the private medical practitioner who, during contacts with patients, could drop a word of warning. Talk will not solve the problem: strong measures are needed substantially to reduce this appalling loss of life each year which, by the exercise of strict hygiene in the kitchen, canteen or restaurant, and by the supervision of staff cleanliness, could to some extent be curtailed.
Jun Lin, Hakim Naceur, Daniel Coutellier and Abdel Laksimi
– The purpose of this paper is to present an efficient smoothed particle hydrodynamics (SPH) method particularly adapted for the geometrically nonlinear analysis of structures.
Abstract
Purpose
The purpose of this paper is to present an efficient smoothed particle hydrodynamics (SPH) method particularly adapted for the geometrically nonlinear analysis of structures.
Design/methodology/approach
In order to resolve the inconsistency phenomenon which systematically occurs in the standard SPH method at the domain’s boundaries of the studied structure, the classical kernel function and its spatial derivatives were modified by the use of Taylor series expansion. The well-known tensile instabilities inherent to the Eulerian SPH formulation were attenuated by the use of the Total Lagrangian Formulation (TLF).
Findings
In order to demonstrate the effectiveness of the present improved SPH method, several numerical applications involving geometrically nonlinear behaviors were carried out using the explicit dynamics scheme for the time integration of the PDEs. Comparisons of the obtained results using the present SPH model with analytical reference solutions and with those obtained using ABAQUS finite element (FE) commercial software, show its good accuracy and robustness.
Practical implications
An additional application including a multilayered composite structure and involving buckling and delamination was investigated using the present improved SPH model and the results are compared to the FE results, they confirmed both the efficiency and the accuracy of the proposed method.
Originality/value
An efficient 2D-continuum SPH model for the geometrically nonlinear analysis of thin and thick structures is proposed. Contrarily to the classical SPH approaches, here the constitutive material relations are used to link naturally the stresses and strains. The Total Lagrangian approach is investigated to alleviate the tensile instabilities problem, allowing at the same time to avoid the updating procedure of the neighboring particles search and therefore reducing CPU usage. The proposed approach is valid for isotropic and multilayered composites structures undergoing large transformations. CPU time savings and better results with the new 2D-continuum SPH formulation compared to the classical continuum SPH. The explicit dynamic scheme was used for time integration allowing a fast resolution algorithm even for highly nonlinear problems.
Details
Keywords
Chun Feng, Shi-hai Li and Eugenio Onate
Continuum-based discrete element method is an explicit numerical method, which is a combination of block discrete element method (DEM) and FEM. When simulating large deformation…
Abstract
Purpose
Continuum-based discrete element method is an explicit numerical method, which is a combination of block discrete element method (DEM) and FEM. When simulating large deformation problems, such as cutting, blasting, water-like material flowing, the distortion of elements will lead to no convergence of the numerical system. To solve the convergence problem, a particle contact-based meshfree method (PCMM) is introduced in. The paper aims to discuss this issue.
Design/methodology/approach
PCMM is based on traditional particle DEM, and use particle contacts to generate triangular elements. If three particles are contact with each other, the element will be created. Once elements are created, the macroscopic constitutive law could be introduced in. When large deformation of element occurs, the contact relationship between particles will be changed. Those elements that do not meet the contact condition will be deleted, and new elements that coincide with the relationship will be generated. By the deletion and creation of elements, the convergence problem induced by element distortion will be eliminated. To solve FEM and PCMM coupled problems, a point-edge contact model is introduced in, and normal and tangential springs are adopted to transfer the contact force between particles and blocks.
Findings
According to the deletion and recreation of elements based on particle contacts, PCMM could simulate large deformation problems. Some numerical cases (i.e. elastic field testing, uniaxial compression analysis and wave propagation simulation) show the accuracy of PCMM, and others (i.e. soil cutting, contact burst and water-like material flowing) show the rationality of PCMM.
Originality/value
In traditional particle DEM, contact relationships are used to calculate contact forces. But in PCMM, contact relationships are adopted to generate elements. Compared to other meshfree methods, in PCMM, the element automatic deletion and recreation technique is used to solve large deformation problems.
Details
Keywords
Emir Malikov, Shunan Zhao and Jingfang Zhang
There is growing empirical evidence that firm heterogeneity is technologically non-neutral. This chapter extends the Gandhi, Navarro, and Rivers (2020) proxy variable framework…
Abstract
There is growing empirical evidence that firm heterogeneity is technologically non-neutral. This chapter extends the Gandhi, Navarro, and Rivers (2020) proxy variable framework for structurally identifying production functions to a more general case when latent firm productivity is multi-dimensional, with both factor-neutral and (biased) factor-augmenting components. Unlike alternative methodologies, the proposed model can be identified under weaker data requirements, notably, without relying on the typically unavailable cross-sectional variation in input prices for instrumentation. When markets are perfectly competitive, point identification is achieved by leveraging the information contained in static optimality conditions, effectively adopting a system-of-equations approach. It is also shown how one can partially identify the non-neutral production technology in the traditional proxy variable framework when firms have market power.
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Keywords
Nigel Rees, Patrick Rees, Lois Hough, Dylan Parry, Nicola White and Brady Bowes
Ambulance services staff worldwide have long been at risk of encountering violence and aggression directed towards them during their work. Verbal forms of violence and aggression…
Abstract
Purpose
Ambulance services staff worldwide have long been at risk of encountering violence and aggression directed towards them during their work. Verbal forms of violence and aggression are the most prevalent form, but sometimes incidents involve physical injury, and on rare occasions homicides do occur. Exposure to such violence and aggression can have a lasting negative impact upon ambulance staff and has been associated with increased levels of stress, fear, anxiety, emotional exhaustion, depersonalisation and burnout syndrome. Despite the significance of this issue, little progress has been made to tackle it. The purpose of this paper is to describe this multi-agency approach being taken in Wales (UK) to reduce such harms from violence and aggression directed towards ambulance services staff.
Design/methodology/approach
An interpretative post-positivist narrative methodology and policy analysis approach was followed. Snowball methods of gathering data were used to construct this narrative involving meetings, telephone calls, review of policy documents, legislation and academic literature.
Findings
The authors report how tackling violence and aggression directed towards emergency workers has become a priority within Wales (UK), resulting in policy developments and initiatives from groups such as the UK and Welsh Government, the Welsh Ambulance Services National Health Services (NHS) Trust, Health Boards, the NHS Wales Anti-Violence Collaborative and the Joint Emergency Services Group (JESG) in Wales. This has included changes in legislation such as the Assaults on Emergency Workers (Offences) Act 2018 that came into force on 13th November 2018 and policy changes such as the obligatory responses to violence in health care and the JESG #WithUsNotAgainst Us campaign. Our study however reflects the complexity of this issue and the need for further high-quality research.
Originality/value
The experiences and activities of Wales (UK) reported in this paper adds to the international body of knowledge and literature on violence and aggression directed towards ambulance services staff.
Details
Keywords
Many scholars have noted that, since at least 1790, U.K. economic fluctuations have seemed to reach major peaks every 7–10 years. Keynes (1936, ch.18) used the elements of his…
Abstract
Many scholars have noted that, since at least 1790, U.K. economic fluctuations have seemed to reach major peaks every 7–10 years. Keynes (1936, ch.18) used the elements of his theory to explain non‐periodic economic fluctuations. His explanation of periodic fluctuations, i.e. cycles, appears in Chapter 22 of the General Theory. As is well known, he believed that fluctuations in “animal spirits” (that were often only loosely connected with the cost and the real rate of return on capital) led to oscillations in investment which, combined with the durability of capital goods, caused the duration of modern major cycles; fluctuations in liquidity preference and the propensity to consume played lesser roles. Bowing to Jevons (1964), Keynes also noted that unstable agricultural inventories could have been a source of waves in the early 19th Century when agriculture was relatively more important in the U.K. But Keynes did not demonstrate just how his investment theory implied a definite cycle period, because he did not merge his multiplier with the accelerator principle to provide an endogenous explanation of periodic turning points in output. Consequently, as Hicks (1950, p. l) notes, Keynes did not demonstrate how investment and income could peak every 7–10 years; his was really a theory of nonperiodic waves.