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Measurement of surface strain in hostile environments remains a significant metrology challenge. An elegantly simple non–contact method is to measure the change in pitch of a reflective diffraction grating bonded to the surface of interest. The grating is probed with a laser beam and the change in angular position of diffracted orders is detected as the pitch changes due to surface strain. Robust application of this technique has not been possible due to assumptions such as near–normal incidence, which were necessary in predicting the angular position of diffracted orders from the existing two–dimensional theory. This paper introduces a new three–dimensional theory of diffraction, which obviates the need for these assumptions. Importantly, the theory shows that the angular position of orders can be determined for arbitrary orientation of the grating relative to the incident probe beam. This latter development is critical for success in a practical application. It is now possible to micro–machine reflective gratings directly into a surface or surface coating and thus avoid problems with creep in the bonding material. Together with the new theory, this idea now has the potential to revolutionize how strain will be measured in the future.

The potential for use of butter as a widely available, relatively uniform lipid-rich matrix for the determination of spatial distributions of persistent organic pollutants has already been demonstrated. The present study determines the contributions to toxicity equivalence (TEQ) from polychlorinated dioxins and furans (PCDD/Fs) and polychlorinated biphenyls (PCBs) using butter samples from 24 countries world wide. Concentrations of PCDD/Fs and dioxin-like PCBs ranged from 0.07 to 5.69 pg ΣWHO-TEQ g-1 lipid. For most samples, PCDD/F TEQ fell within ranges reported for European dairy products over the last decade (0.3-2 pg g-1 lipid I-TEQ), though a single sample from Spain was a notable exception. Other than this sample, the highest values were recorded for samples from the Netherlands and Italy, with those from India, China and Tunisia also being relatively high. The contribution from non- ortho -PCBs was particularly significant in samples from Germany, Austria, Italy, the Czech Republic, Tunisia, India and Argentina. Although overall TEQs were generally highest in European and Mediterranean butters, elevated levels were also apparent in industrializing regions of Asia (India, China) and Latin America (Argentina). More detailed regional studies would be necessary to identify likely dioxin and PCB sources in each case. Nevertheless, this study supports the utility of butter as a monitoring matrix that may be especially applicable in regions for which monitoring programmes are currently lacking.

In a factory which produces veneer boards from birch wood, grading of the boards into different quality categories is usually part of the production process. To improve the efficiency of grading, attempts are being made to automate it using automated visual inspection (AVI). Integral to the process of inspection is segmentation. Segmentation is the part of the AVI process concerned with separating clear wood and defective areas in the image. This paper describes a system that is used to segment the images of birch wood boards. The system consists of four modules which are called global adaptive thresholding, multi-level thresholding, row-by-row adaptive thresholding and vertical profiling. The paper gives details of the four modules and presents the results obtained in segmenting images of a large sample of birch wood boards.

Digested sludge was applied to plowed arable and pasture grassland plots and losses of specific volatile organic compounds (VOCs), polychlorinated biphenyls (PCBs), polychlorinated dibenzo‐p‐dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), and chlorophenols (CPs) monitored over 260 d. Sludge addition increased soil concentrations of all compounds in the plowed plot. VOCs, PCBs, and CPs concentrations declined to control plot values within 128 d of sludge amendment. Volatilization and biodegradation were considered important loss processes for these compounds. However, PCDD/F and of non‐o‐PCB 77 concentrations did not change consistently and remained elevated above control plot concentrations throughout the monitoring period. At Day 260 410 ± 53 ng ΣPCDD kg−1and 250 ± 10 ng ΣPCDF kg−1was detected in the sludged plot compared to 68 ± 9 ng ΣPCDD kg−1and 170 ± 7 ng ΣPCDF kg−1in the control plot. Data from the pasture plot has highly variable and differences between most contaminant concentrations in the sludged and control plots were insignificant. This was attributed to adherence of much of the applied sludge to vegetation rather than direct application to the soil surface and has important implications for elevated dietry intake of certain persistent organic compounds such as the PCDD/Fs. Further research is needed to evaluate the importance of sludge adherence to vegetation for human exposure to a range of contaminants detected in sludge. Contaminant movement to depth (20 cm) was not detected within 260 d for compounds monitored (VOCs and PCDD/Fs).

We have performed a prospective study in 100 adults (ASA I or II) undergoing day-case dental extraction to compare the conditions for intubation and the postoperative sequelae of suxamethonium and alfentanil as adjuncts to propofol. The patients were allocated randomly to two groups comparable in age, sex and weight. Successful intubation was achieved in 100% of the suxamethonium group and 90% of the alfentanil group. Of the patients who received suxamethonium, 74% developed myalgia on the day after surgery, compared with 20% in the alfentanil group (P < 0.001). The proportion of patients who developed sore throat was also less in the alfentanil group than in the suxamethonium group (P < 0.05). The proportion of patients who complained of nausea in the two groups was not significantly different. We conclude that alfentanil, as an adjunct to propofol to facilitate tracheal intubation, is more acceptable to patients than suxamethonium in anaesthesia for day-case surgery.

The Shinkansen High-Speed Rail Network of Japan. Edited by A. Straszak and R. Tuch. (Pergamon Press, 1980.) ISBN 0 08 024444 0 [Pp. 462.] £85.00.The Shinkansen Program: Transportation, Railway, Environment, Regional, and National Development Issues. Edited by A. Straszak. (International Institute for Applied Systems Analysis in Laxenburg, 1981.) ISBN 3 7045 0011 9 [Pp. 518.] $20.Danger on the Road: the Needless Scourge. By Stephen Plowden and Mayer Hillman. (Policy Studies Institute, London 1984.) [Pp. 239.] Paper bound, £6.50.Infrastruktura Transportowa Republiki Federalnej Niemiec (Problemy przestrzenne). Transport Infrastructure of the Federal Republic of Germany (Spatial Problems) (in Polish). By T. Lijewski. (Polish Academy of Sciences, 1982.) [Pp. 151.] Złoty 100.Road Users and the Police. (1983). By M. C. Dix and A. D. Layzell. (Croom Helm in association with the Police Council, 1983.) [Pp. 169.] £6.95.

Objectives & BackgroundWith 1.9 million neurons lost every minute a stroke is untreated1, rapid assessment and management is a time critical medical emergency, and is reliant on robust Emergency Department (ED) systems. Rapid access to CT imaging is an immediate priority to allow exclusion of patients with haemorrhagic stroke, an absolute contraindication to thrombolysis. Our QI project aimed to reduce the time from arrival in ED to CT scan for patients presenting with potentially thrombolysable stroke.MethodsUsing a combination of live and simulated stroke scenarios, we process-mapped the care of potentially thrombolysable patients through the ED at Forth Valley Royal Hospital. We identified ‘unnecessary’ delays from non-value adding activity and following consultation with the Scottish Ambulance Service, Radiology & Neurology, created a new pre-alert procedure and streamlined protocol for this patient group which facilitated rapid assessment, stabilization and early access to CT imaging.We used a multi-modal approach to deliver change which included weekly clinical governance meetings, teaching for medical & nursing staff, in-situ simulation to educate and stress the system, regular safety brief announcements and the development of a ‘Stroke Awareness Week' at our hospital.ResultsDoor to CT time was reduced by 40%, from 30 minutes (median 23) to 18 minutes (median 13), comparing 4 month sample periods before and after changes. During our QI project, Door-to-Needle (DTN) time has reduced from a mean of 81 minutes (in 2015) to a mean of 64 minutes (2016YTD).ConclusionEarly thrombolysis has been shown to improve outcomes in patients with ischaemic stroke.2 Reducing ‘Door-to-CT' scan time in the ED is an important step in enabling a reduction in the overall DTN time. This can be achieved by stream-lining key processes in the patient journey through the ED. A multi-modal approach ensured this change was introduced safely and effectively whilst re-enforcing a core change to standard working practice. Further work on process mapping and the delivery of thrombolysis is the next obvious step in further reduction in DTN time.[Figure]