Two geometrical isomers of linoleic acid: Improved total syntheses

The total syntheses of 9(Z),12(E)- and 9(E),12(Z)-octadecadienoic acids have been carried out. A useful intermediate in both syntheses, 8-bromo-octanoic acid, recently has become available from commercial sources. This compound has been used to expedite the preparation of these isomers. The remaining carbon atoms were derived from propargyl alcohol along with either 1-heptyne or acetylene and 1-bromopentane. Because the overall yield for each sequence was roughly 15% and there were no extraordinary reaction conditions in any of the synthetic steps, the compounds could be prepared readily in multiple gram quantities. The syntheses of the two compounds were supported by data from a variety of spectroscopic techniques.     

Survey of construction lawyers' attitudes and practice in the use of ADR in contractors' disputes

Continuing a survey of contractors' perceptions about alternative dispute resolution (ADR) this paper seeks to report an investigation of the level of involvement of legal advisors to the construction industry in the dispute resolution process and the perceptions that legal professionals have about the use of ADR in construction disputes. The research findings are that contractors are likely to involve lawyers in the dispute resolution procedure, particularly when disputes concern a legal issue, when the parties to the dispute are entrenched in their argument, or when the other party insists on using legal professional assistance. In these defined circumstances, legal advisors will be influential in determining the potential use of ADR. The paper concludes that lawyers are unlikely to recommend ADR for most disputes between contractors, particularly if the dispute resolution process is perceived to involve the use of delay by main contractors, if the parties are fixed in their arguments or if they are exhibiting adversarial behaviour in their approach to the dispute. In these circumstances lawyers and their clients prefer the force of the formal systems over conciliatory ADR procedures.     

Seeing through dust and water vapor: Millimeter wave radar sensors for mining applications

This paper defines the issues required for the development of successful visualization sensors for use in open cut and underground mines. It examines the mine environment and considers both the reflectivity of the rock and attenuation effects of dust and water droplets. Millimeter wave technology, as an alternative to the more commonly used laser and sonar implementations, is selected due to its superior penetration through adverse atmospheric conditions. Of the available radar techniques, frequency modulated continuous wave (FMCW) is selected as being the most robust. The theoretical performance of a number of 77 and 94 GHz FMCW millimeter wave radar systems is determined and these confirm the capability of these sensors in the mining environment. Implementations of FMCW radar sensors for simple ranging and three‐dimensional surface profiling are discussed before data obtained during field trials in mines is presented to justify the selection of this technology. © 2007 Wiley Periodicals, Inc.     

Quantifying the dispersion of carbon nanotubes in thermoplastic-toughened epoxy polymers

The distribution of particles within modern materials must be defined to understand the change in properties attained by their addition. Two methods of analysis, which use different size scales, are presented here. These methods are applied to characterise the dispersion of multi-walled carbon nanotubes in a thermoplastic-toughened epoxy polymer. First, the greyscale method uses transmission optical micrographs, and calculates the ratio of the variance/mean of the greyscale values. Higher values indicate a greater degree of clustering; lower values may be described as showing a ‘better’ distribution of nanotubes, hence allowing the results to be ranked. This method is relatively easier to carry out, but care must be taken to use a consistent small thickness of sample. Secondly, the quadrat analysis uses transmission electron micrographs of the same materials, after identifying the centre of each nanotube observed. This defines the distribution on the scale of the nanotubes. Peaks in the relationship between the ratio of the variance/mean and cell size are related to microstructural features such as agglomeration. This scale is expected to be related to the scale of microstructural deformation mechanisms which determine global material properties.     

Serious mental health problems: policy changes

Recent developments in services and strategies for helping people with serious mental health problems represent a watershed in mental health provision. This has implications not only for specialist mental health nursing, but also-- as increasing numbers of people with serious mental health problems live in the community-- for nurses working in all areas of health care, who will have to play a role in meeting their needs. This article describes current developments in policy and practice, and seeks to explain the basic principles of working with people in this client group.     

Sampling and transportation of food materials for freeze-fracture from the industrial environment

A simple holder is described which enables the multiple sampling of food materials for freeze-fracturing in an industrial environment. The holder allows frozen samples to be transferred safely to the laboratory under liquid nitrogen for freeze-fracturing and examination by transmission electron microscopy. The technique has been successfully applied to sampling food from pilot plant and production lines under factory conditions.     

Cost effectiveness of community leg ulcer clinics: randomised controlled trial

OBJECTIVES: To establish the relative cost effectiveness of community leg ulcer clinics that use four layer compression bandaging versus usual care provided by district nurses. DESIGN: Randomised controlled trial with 1 year of follow up. SETTING: Eight community based research clinics in four trusts in Trent. SUBJECTS: 233 patients with venous leg ulcers allocated at random to intervention (120) or control (113) group. INTERVENTIONS: Weekly treatment with four layer bandaging in a leg ulcer clinic (clinic group) or usual care at home by the district nursing service (control group). MAIN OUTCOME MEASURES: Time to complete ulcer healing, patient health status, and recurrence of ulcers. Satisfaction with care, use of services, and personal costs were also monitored. RESULTS: The ulcers of patients in the clinic group tended to heal sooner than those in the control group over the whole 12 month follow up (log rank P=0.03). At 12 weeks, 34% of patients in the clinic group were healed compared with 24% in the control. The crude initial healing rate of ulcers in intervention compared with control patients was 1.45 (95% confidence interval 1.04 to 2. 03). No significant differences were found between the groups in health status. Mean total NHS costs were 878.06 pounds per year for the clinic group and 859.34 pounds for the control (P=0.89). CONCLUSIONS: Community based leg ulcer clinics with trained nurses using four layer bandaging is more effective than traditional home based treatment. This benefit is achieved at a small additional cost and could be delivered at reduced cost if certain service configurations were used.     

Back pain claim rates and the business cycle

The causes of reported occupational back pain are controversial. Many observers appear to believe that job insecurity increases back pain compensation claims during recessions. The purpose of this study was to formally examine the impact of macro-economic forces-the business cycle-on the incidence of lost-time back pain claim rates in order to elicit clues to both its aetiology and reporting patterns. For Ontario between 1975 and 1993, age- and sex-adjusted lost-time back pain claim rates, stratified by industry sector (construction, manufacturing and trade), were regressed on the unemployment rate of the industry sector using time series methods. As a comparison group, the association between "acute" claim (fractures, lacerations, etc.) and the business cycle was also tested. Both back pain claim rates and acute claim rates increased during boom periods and decreased during recessionary periods. Time series analyses confirmed that these associations were statistically significant. The elasticities between claim rates and the unemployment rate were similar for back pain claims and acute claims. In addition, these associations were consistent in direction across all three industrial sectors tested. These results rebut the view that back pain claims increase during recessionary times.