11 research outputs found
Investigations of the heat transfer and friction coefficient in a duct with surface injection: Experimental approach
Several engineering equipment's and installations often operates under severe conditions such as elevated temperatures and high pressures in turbines, combustion furnaces and chambers, engines, generators, etc. This results in lessening the life time of such facilities. Hence, many efforts have been made to study the effects of such conditions with few focusing on the effects of surface injection on heat transfer (HT) characteristics. In this work, a test rig was developed to investigate the influence of blowing ratio (M), from 0 to 4, as well as injection angle Φ (from 30° to 150°) on the flow and HT characteristics. The velocity distribution was measured using particle image velocimetry (PIV) technique. A significant increase in both friction coefficient and heat transfer were obtained by increasing the Re for the case of Φ > 90° at constant M and a decrease for angles Φ < 90°. Results indicated that, the average Nusselt number (Nu) ratio increases with increasing the M for all injection angles, with minimum and maximum values occurring at the angles of 60° and 150°, respectively. General correlations for the Nu and friction factor have been proposed as functions of the flow, Φ, and M based on the results of this work. The correlations, were found to represent the experimental data with reasonable accuracy. Also, the experimental results were well compared with the previous work with highest deviation of about 6.42% for the ratio of heat coefficient
A statistical mixture model for estimating the proportion of unreduced pollen grains in perennial ryegrass (Lolium perenne L.) via the size of pollen grains
Overdose among youth in Bahrain: psycho-social characteristics, contact with helping agencies and problems
EMS-induced cytomictic variability in safflower (Carthamus tinctorius L.)
Seeds of safflower (Carthamus tinctorius L.) were subjected to three treatment durations (3h, 5h and 7h) of 0.5 % Ethyl Methane Sulphonate (EMS). Microsporogenesis was carried out in the control as well as in the treated materials. EMS treated plants showed interesting feature of partial inter-meiocyte chromatin migration through channel formation, beak formation or direct cell fusion. Another interesting feature noticed during the study was the fusion among tetrads due to wall dissolution. The phenomenon of cytomixis was recorded at nearly all the stages of microsporogenesis connecting from a few to several meiocytes. Other abnormalities such as laggards, precocious movement, bridge and non disjunction of chromosomes were also recorded but in very low frequencies. The phenomenon of cytomixis increased along with the increase in treatment duration of EMS. Cells with these types of cytomictic disturbances may probably result in uneven formation of gametes or zygote, heterogenous sized pollen grains or even loss of fertility in future.Семена сафлора (Carthamus tinctorius L.) обрабатывали 0.5%-ным этилметансульфонатом (ЭМС) в одном из трех режимов – 3, 5 и 7 ч. Микроспорогенез изучали как в контроле, так и в обработанном материале. Растения, обработанные ЭМС, проявляли интересную особенность частичной интермейоцитной миграции хроматина при формировании каналов, образовании клювообразного выступа или прямом слиянии клеток. Другим обнаруженным в исследовании явлением было слияние тетрад из-за растворения стенки. Феномен цитомиксиса отмечался почти на всех стадиях микроспорогенеза и затрагивал от нескольких до многих мейоцитов. Другие аномалии, такие как отставания, преждевременные движения, мосты и неразделения хромосом, отмечались с незначительной частотой. Феномен цитомиксиса возрастал с увеличением длительности обработки ЭМС. Клетки с этими типами цитомиктических нарушений могут, вероятно, приводить к нерегулярному формированию гамет или зигот, гетерогенных по размеру пыльцевых зерен, или даже к потере фертильности в будущем.Насіння сафлору (Carthamus tinctorius L.) обробляли 0.5%-ним етилметансульфонатом (ЕМС) в одному з трьох режимів – 3, 5 і 7 год. Мікроспорогенез вивчали як у контролі, так і в обробленому матеріалі. Рослини, оброблені ЕМС, виявляли цікаву особливість часткової інтермейоцитної міграції хроматину при формуванні каналів, утворенні дзюбоподібного чи прямому злитті клітин. Іншим виявленим в дослідженні явищем було злиття тетрад через розчинення стінки. Феномен цито- міксису відзначався майже на всіх стадіях мікро-спорогенезу і зачіпав від кількох до багатьох мейоцитів. Інші аномалії, такі як відставання, передчасні рухи, мости і нерозділення хромосом, зустрічались з незнач- ною частотою. Феномен цитоміксису зростав із збільшенням тривалості обробки ЕМС. Клітини з цими типами цитоміктичних порушень можуть, ймовірно, приводити до нерегулярного формування гамет або зигот, гетерогенних за розміром пилкових зерен, або навіть до втрати фертильності в майбутньому
Critical care usage after major gastrointestinal and liver surgery: a prospective, multicentre observational study
Background
Patient selection for critical care admission must balance patient safety with optimal resource allocation. This study aimed to determine the relationship between critical care admission, and postoperative mortality after abdominal surgery.
Methods
This prespecified secondary analysis of a multicentre, prospective, observational study included consecutive patients enrolled in the DISCOVER study from UK and Republic of Ireland undergoing major gastrointestinal and liver surgery between October and December 2014. The primary outcome was 30-day mortality. Multivariate logistic regression was used to explore associations between critical care admission (planned and unplanned) and mortality, and inter-centre variation in critical care admission after emergency laparotomy.
Results
Of 4529 patients included, 37.8% (n=1713) underwent planned critical care admissions from theatre. Some 3.1% (n=86/2816) admitted to ward-level care subsequently underwent unplanned critical care admission. Overall 30-day mortality was 2.9% (n=133/4519), and the risk-adjusted association between 30-day mortality and critical care admission was higher in unplanned [odds ratio (OR): 8.65, 95% confidence interval (CI): 3.51–19.97) than planned admissions (OR: 2.32, 95% CI: 1.43–3.85). Some 26.7% of patients (n=1210/4529) underwent emergency laparotomies. After adjustment, 49.3% (95% CI: 46.8–51.9%, P<0.001) were predicted to have planned critical care admissions, with 7% (n=10/145) of centres outside the 95% CI.
Conclusions
After risk adjustment, no 30-day survival benefit was identified for either planned or unplanned postoperative admissions to critical care within this cohort. This likely represents appropriate admission of the highest-risk patients. Planned admissions in selected, intermediate-risk patients may present a strategy to mitigate the risk of unplanned admission. Substantial inter-centre variation exists in planned critical care admissions after emergency laparotomies
Body mass index and complications following major gastrointestinal surgery: A prospective, international cohort study and meta-analysis
Aim Previous studies reported conflicting evidence on the effects of obesity on outcomes after gastrointestinal surgery. The aims of this study were to explore the relationship of obesity with major postoperative complications in an international cohort and to present a metaanalysis of all available prospective data. Methods This prospective, multicentre study included adults undergoing both elective and emergency gastrointestinal resection, reversal of stoma or formation of stoma. The primary end-point was 30-day major complications (Clavien–Dindo Grades III–V). A systematic search was undertaken for studies assessing the relationship between obesity and major complications after gastrointestinal surgery. Individual patient meta-analysis was used to analyse pooled results. Results This study included 2519 patients across 127 centres, of whom 560 (22.2%) were obese. Unadjusted major complication rates were lower in obese vs normal weight patients (13.0% vs 16.2%, respectively), but this did not reach statistical significance (P = 0.863) on multivariate analysis for patients having surgery for either malignant or benign conditions. Individual patient meta-analysis demonstrated that obese patients undergoing surgery formalignancy were at increased risk of major complications (OR 2.10, 95% CI 1.49–2.96, P < 0.001), whereas obese patients undergoing surgery for benign indications were at decreased risk (OR 0.59, 95% CI 0.46–0.75, P < 0.001) compared to normal weight patients. Conclusions In our international data, obesity was not found to be associated with major complications following gastrointestinal surgery. Meta-analysis of available prospective data made a novel finding of obesity being associated with different outcomes depending on whether patients were undergoing surgery for benign or malignant disease