A study of wire breakup and in-flight particle behaviour during wire flame spraying of aluminium

Although wire flame spraying has been used for many years, there has been relatively little attention given to understanding the process dynamics. In this work, imaging of the molten wire tip, particle imaging using the Oseir Spray Watch system and particle capture (wipe tests) have all been employed to quantify plume behaviour. Aluminium wire feedstock is melted and then breaks-up close to the exit of the spray nozzle in a non-axisymmetric manor. The mean velocity and diameter of the particles detected by the Spray Watch system change little with stand-off distance with values of approximately 280 m/s and 70 μm respectively for the spray parameters employed. The particle diagnostic system could not detect particles ⪅ 45 μm in diameter and it is estimated that these account for no more than 53 % of the sprayed material. Overall, wire flame spraying generates a surprisingly stable particle stream

Analysis of the effects of environment on protein body development in wheat (Triticum aestivum, L.) caryopses

SIGLEAvailable from British Library Document Supply Centre- DSC:D062113 / BLDSC - British Library Document Supply CentreGBUnited Kingdo

Mechanisms leading to excess alpha-amylase activity in wheat (Triticum aestivum, L) grain in the UK

The frequency and mechanisms of four modes of alpha -amylase enzyme accumulation in U.K. wheat, retained pericarp alpha -amylase activity (RPAA), pre-maturity alpha -amylase activity (PMAA), pre-maturity sprouting (PrMS) and post-maturity sprouting (PoMS), were investigated in field and laboratory experiments. Of 56 cultivar site year combinations (four model cultivars grown at up to four sites from 1994–1997), enzyme activity was detected in 32 cases, in 23 cases sufficient to reduce Hagberg falling number (the usual industry measure of alpha -amylase) below the commercial criterion (250 s). The frequency of occurrence of different modes of enzyme accumulation was in the order PoMS>PMAA>PrMS>RPAA. Both PMAA and PrMS were more common than expected and the most usual pattern was for alpha -amylase to accumulate by several modes. Although green grains are rejected as impurities, study of grain colour in relation to pericarp alpha -amylase activity showed that the enzyme could persist in non-green grains in levels sufficient to affect the Hagberg value. Two factors thought to promote PMAA, grain drying rate and transient changes in temperature in early development, were studied in the field and controlled environment cabinets. No significant difference was found in grain drying rate between samples where PMAA was or was not identified. However, out of 19 transfers from a cool (16/10 °C) to a warm (26/20 °C) temperature regime, six led to significant increases in PMAA. No transfers after 45% grain moisture increased PMAA. PrMS occurred as early as 67% grain moisture and susceptibility usually increased with stage of development, being greatest in the grain dough stage. PrMS susceptibility varied with cultivar (in the same order as PoMS sensitivity) and was affected by environmental factors

Improvement of oilseed rape establishment by seed selection or seed treatment

Includes bibliographical referencesSIGLEAvailable from British Library Document Supply Centre- DSC:4303. 4478(no 313) / BLDSC - British Library Document Supply CentreGBUnited Kingdo

Effects of pericarp alpha-amylase activity on wheat (Triticum aestivum) Hagberg falling number

Pericarp alpha‐amylase activity in wheat has largely been ignored as a potential cause of low Hagberg falling number (HFN) in the UK, because pericarp alpha‐amylase enzymes have been thought too temperature‐sensitive to affect HFN and are usually degraded by harvest. Nevertheless, there are several circumstances where immature grains may be present in harvested grain. Therefore, we tested the hypotheses that pericarp alpha‐amylase enzymes in immature grains could lower HFN, but also that inactivation of the enzymes during drying and storage could ameliorate the effect. The first hypothesis was tested by addition of large amounts of pericarp alpha‐amylase activity from freeze‐dried, defrosted or fresh green grains to high HFN flours of low alpha‐amylase activity, followed by HFN measurement. Enzyme assay and HFN analysis assessed the effect of drying on pericarp alpha‐amylase activity after different storage treatments. Addition of pericarp alpha‐amylase, from all three sources, to high HFN flours caused an exponential decrease in HFN. A drop in HFN from over 470 s to below 250 s resulted from addition of 5–10% by weight of green grains. Between 35–70% of the α‐AMY‐2 activity in immature grains was eliminated by air‐drying at 20°C over 8–10 days, although the residual activity could still lower HFN. Thus, pericarp alpha‐amylase activity may be a cause of low HFN in some UK wheat crops

Variation in dormancy duration of the UK wheat cultivar Hornet due to environmental conditions during grain development

Dormancy of wheat grains, the property conferring sprouting resistance, is affected by environmental conditions experienced during grain development. We investigated the hypothesis that short dormancy duration in U.K. wheat grain (thus a high risk of post-maturity sprouting) is related to weather conditions, i.e. high temperatures during grain development. Four wheat varieties were grown at four sites ranging from the far south to the far north of the country in the years 1995–1997,ensuring different temperature and rainfall conditions during grain development. This paper focuses on one variety, Hornet, which has a high sprouting resistance rating. Other varieties gave similar results. Serial laboratory germination tests (seven days, 20°C) at 100°C-dayintervals were used to measure dormancy duration, which was assessed from logistic curves fitted to the data. During the experiment the mean temperatures during grain development differed by over4°C, due to the site × year effect. Significant effects (p>0.05) of site and year (i.e. weather) on dormancy were found, when definitions of dormancy duration of DA (number of days from anthesis to 50% germination in seven days at 20°C) or DP (number of days from physiological maturity at 45% grain moisture to 50% germination) were used. Dormancy was markedly shorter in the hot, dry year 1995 compared to the cooler, wetter years 1996 and 1997. A relationship, as postulated by Belderok, between accumulated temperature during the dough stage of grain filling and dormancy duration was not found. However, a relationship of dormancy duration to the mean temperature during grain development was found, with short dormancy periods occurring after high mean temperatures were experienced

Caudal analgesia with buprenorphine for postoperative pain relief in children

Caudal buprenorphine was investigated as a postoperative analgesic in a randomized double blind study in thirty children aged 5-12 years undergoing lower abdominal and lower limb surgery. Comparison was made between two groups of patients, one group receiving plain bupivacaine and the other a combination of plain bupivacaine with buprenorphine. Postoperative analgesia was assessed using a linear analogue scale, and by the response to direct questioning of children using an illustration of sequence of faces. Any untoward side effects and the need for additional analgesics were recorded. The degree and duration of analgesia was far superior in the buprenorphine group and there was a highly significant difference in the requirement of postoperative analgesia between the two groups. There were no major adverse side effects and no motor weakness in either groups, however the incidence of nausea and vomiting was higher in the buprenorphine group. It is concluded that a combination of bupivacaine with buprenorphine administered through the caudal epidural space is a safe and reliable means of providing postoperative pain relief in children for up to 24 h