Application of the theory of bending to the structural members of ships

On my return to employment in a shipyard design office after graduating in 1947, I was required to solve many problems of a non-routine nature. These were associated with almost every branch of naval architecture, but structural strength problems predominated and most of the latter were concerned with the local strength of the structural members of ships rather than strength of the hull as a whole. When the opportunity arose for me to carry out research at the University it was not unnatural that I should chose to examine this problem. The main objective was to decide what precautions must be taken when using the theory of elastic bending to analyse the strength of the structural members of ships and to formulate a suitable theory which could be applied in the design offices of shipyards. With the latter end in view it was necessary that the final theory should be as simple as possible and, bearing in mind that in general neither the loads applied to most ship structures nor the strength characteristics of the materials used were accurately known, it was permissible to omit refinements of the theory which would affect the results by less than a few percent. To achieve this object the stresses and deflections measured in the experiments at Glengarnock were compared with those predicted by the theory of bending, and the theory was modified until it could be made to agree with the measurements with reasonable accuracy. This analysis was supplemented by some experimental work on board ship which showed that the theories developed could be applied also in practice. Although the research did not necessarily proceed in a straightforward manner the results are presented in this thesis in a logical sequence. There are five main chapters with a review of the work in a sixth chapter, and an Appendix. Two problems which were peculiar to shipbuilding appeared to be important. The first of these was the difficulty of deciding what degree of constraint there was at the ends of the structural members of ships. To enable this to be taken into account I modified one of the most useful tools of structural analysis - the method of moment distribution. An early version of the theory was sent to the Institution of Naval Architects in an interim report on the research and was published in 1952 (ref. Al), but later revisions were so extensive that a full account of the final theory is given in Chapter I of the thesis. The theory allows for the constraint at the ends of loaded beams which may be straight or curved in the plane of the applied loads and may have constant or variable cross sections. The second problem was that of shear lag in stiffened plating. This occurs in ships and aircraft and had received a good deal of theoretical attention. Many of the theories indicated conflicting results and hardly any experimental work had been published; the G-lengamock results were inconclusive. I therefore investigated the matter by theory and experiment, and the results were published in 1955 by the Institution of Naval Architects. A copy of this paper, together with the discussion, is bound as an Appendix at the end of the thesis and a summary (and one small extension which has a bearing on later work) is given in Chapter II. It is shown that shear lag is usually unimportant in shipbuilding, but a new method of calculating shear lag effects is described for use when required. With this foundation it was found to be possible to commence an analysis of the Glengarnock results and this is discussed in Chapter III. Altogether the results of about 300 experiments were examined. It was found to be possible to correlate a large number of these by means of the theory described in Chapter I, Further modifications or additions to the theory of bending were required in order to account for discrepancies noted in certain classes of specimen, and these are discussed as they arise. An attempt to predict the experimental results entirely from theoretical considerations met with a fair amount of success, A paper on the analysis is nearly ready for submission to the Institution of Naval Architects. In Chapter IV there is a description of some experiments which I carried out on board ship. Measured deflections are compared with those predicted theoretically and, although agreement is not perfect, it is shown that it is possible to estimate fairly accurately the constraint at the ends of a bulkhead stiffener with welded brackets, at any rate in this particular case, by the theory outlined in Chapter I, The theories described are all based on elastic analysis of beams but in Chapter V there is a brief discussion of the possibilities of using the theory of plastic bending in shipbuilding. This is followed in Chapter VI by a review of the research and some conclusions and suggestions for further work

Alcohol-induced retrograde facilitation renders witnesses of crime less suggestible to misinformation

RATIONALE: Research has shown that alcohol can have both detrimental and facilitating effects on memory: intoxication can lead to poor memory for information encoded after alcohol consumption (anterograde amnesia) and may improve memory for information encoded before consumption (retrograde facilitation). This study examined whether alcohol consumed after witnessing a crime can render individuals less vulnerable to misleading post-event information (misinformation). METHOD: Participants watched a simulated crime video. Thereafter, one third of participants expected and received alcohol (alcohol group), one third did not expect but received alcohol (reverse placebo), and one third did not expect nor receive alcohol (control). After alcohol consumption, participants were exposed to misinformation embedded in a written narrative about the crime. The following day, participants completed a cued-recall questionnaire about the event. RESULTS: Control participants were more likely to report misinformation compared to the alcohol and reverse placebo group. CONCLUSION: The findings suggest that we may oversimplify the effect alcohol has on suggestibility and that sometimes alcohol can have beneficial effects on eyewitness memory by protecting against misleading post-event information

Quality of life after postmastectomy radiotherapy in patients with intermediate-risk breast cancer (SUPREMO): 2-year follow-up results of a randomised controlled trial

Background Postmastectomy radiotherapy in patients with four or more positive axillary nodes reduces breast cancer mortality, but its role in patients with one to three involved nodes is controversial. We assessed the effects of postmastectomy radiotherapy on quality of life (QOL) in women with intermediate-risk breast cancer. Methods SUPREMO is an open-label, international, parallel-group, randomised, controlled trial. Women aged 18 years or older with intermediate-risk breast cancer (defined as pT1–2N1; pT3N0; or pT2N0 if also grade III or with lymphovascular invasion) who had undergone mastectomy and, if node positive, axillary surgery, were randomly assigned (1:1) to receive chest wall radiotherapy (50 Gy in 25 fractions or a radiobiologically equivalent dose of 45 Gy in 20 fractions or 40 Gy in 15 fractions) or no radiotherapy. Randomisation was done with permuted blocks of varying block length, and stratified by centre, without masking of patients or investigators. The primary endpoint is 10-year overall survival. Here, we present 2-year results of QOL (a prespecified secondary endpoint). The QOL substudy, open to all UK patients, consists of questionnaires (European Organisation for Research and Treatment of Cancer QLQ-C30 and QLQ-BR23, Body Image Scale, Hospital Anxiety and Depression Scale [HADS], and EQ-5D-3L) completed before randomisation, and at 1, 2, 5, and 10 years. The prespecified primary outcomes within this QOL substudy were global QOL, fatigue, physical function, chest wall symptoms, shoulder and arm symptoms, body image, and anxiety and depression. Data were analysed by intention to treat, using repeated mixed-effects methods. This trial is registered with the ISRCTN registry, number ISRCTN61145589. Findings Between Aug 4, 2006, and April 29, 2013, 1688 patients were enrolled internationally and randomly assigned to receive chest wall radiotherapy (n=853) or not (n=835). 989 (79%) of 1258 patients from 111 UK centres consented to participate in the QOL substudy (487 in the radiotherapy group and 502 in the no radiotherapy group), of whom 947 (96%) returned the baseline questionnaires and were included in the analysis (radiotherapy, n=471; no radiotherapy, n=476). At up to 2 years, chest wall symptoms were worse in the radiotherapy group than in the no radiotherapy group (mean score 14·1 [SD 15·8] in the radiotherapy group vs 11·6 [14·6] in the no radiotherapy group; effect estimate 2·17, 95% CI 0·40–3·94; p=0·016); however, there was an improvement in both groups between years 1 and 2 (visit effect −1·34, 95% CI −2·36 to −0·31; p=0·010). No differences were seen between treatment groups in arm and shoulder symptoms, body image, fatigue, overall QOL, physical function, or anxiety or depression scores. Interpretation Postmastectomy radiotherapy led to more local (chest wall) symptoms up to 2 years postrandomisation compared with no radiotherapy, but the difference between groups was small. These data will inform shared decision making while we await survival (trial primary endpoint) results. Funding Medical Research Council, European Organisation for Research and Treatment of Cancer, Cancer Australia, Dutch Cancer Society, Trustees of Hong Kong and Shanghai Banking Corporation