68 research outputs found
The Engineering Pavilion – a learning space developing engineers for the global community
Of the many factors, formal and informal, that facilitate engineering students’ skills development and engineering identity, interactions with fellow students, teachers and industry are key. The Engineering Pavilion at Curtin facilitates these interactions in a building dedicated to students, providing a ‘home’ throughout their studies, a base for industry to engage with students, and stimulating concept understanding in a live (instrumented) building and learning space.To understand how students develop their learning, experience and behavior in this space, we need to understand the culture of the Pavilion. The theories of Pierre Bourdieu and the key concept of habitus, allow us to operationalize the concept of culture and understand the shifting mixtures of values and beliefs that underlie behavior. An ethnographic approach, studying a culture-shaping group at a single site, was employed.The Pavilion, recently opened, already supports student interactions. In moving from a habitus of student to graduate engineer, students’ perceptions and behavior are influenced by these interactions. The larger field of engineering education also changes through adoption or revaluing new forms of behavior through the curriculum. The Pavilion hosts the development of changing habitus and exemplifies how innovative learning spaces can influence the norms of long-established disciplines
10th international conference on gas-liquid and gas-liquid-solid reactor engineering preface
Following the success of the nine previous conferences on Gas–Liquid and Gas–Liquid–Solid reactor Engineering which were held at Columbus, OH, USA (1992), Cambridge, UK (1995), Kanagawa, Japan (1997), Delft, The Netherlands (1999), Melbourne, Australia (2001), Vancouver, Canada (2003), Strasbourg, France (2005), New Delhi, India (2007) and Montreal, Canada (2009) the tenth conference with the same theme is being held in Braga, Portugal, from 26 to 29 June 2011. This conference will cover all aspects of multiphase reactors related to progress made in the understanding, performance and operation of these reactors and will bring together scientists and engineers from universities and industry.
The involvement of top researchers in Gas–Liquid and Gas–Liquid–Solid Reactor Engineering, the high quality of the papers presented and the line of continuity that has been guaranteed by the leadership of Prof. L.S. Fan of Ohio State University and the other members of the International Scientific Committee has made GLS a leading conference in Chemical Engineering. GLS has been held at regular intervals, every two years and in order to attract professionals across the globe, the venue of the GLS conference is shifted in a thoughtful manner amongst the continents. This conference has become an important meeting point for the exchange of views among scientists and engineers in one of the most important and complex issues in chemical engineering science and practice.
The organizing committee is very pleased to be associated with Elsevier to have, as in most of the previous GLS editions, the proceedings of GLS10 published in Chemical Engineering Science (CES). As a result of a strict peer review process aiming at keeping with the highest standards of the journal, the GLS10 CES special issue includes a total of 39 papers, selected from the 150 Abstracts that were submitted to GLS10.
Our sincere acknowledgments are due to Professor Anton P.J. Middelberg, the Executive Editor of CES, for his cooperation throughout the reviewing process. Also, we would like to express our gratitude to all the reviewers that made possible a timely publication of this special issue. Thanks are due to Genevieve Green from Elsevier for the excellent management of this special issue publication.
Finally, it is our pleasure to dedicate this GLS10 CES special issue to Professor John Davidson as a tribute to his pioneering work and extraordinary contributions to Gas–Liquid and Gas–Liquid–Solid Reactor Engineering and to Chemical Engineering
Hydrodynamic Simulation of Cyclone Separators
Cyclone separators are commonly used for separating dispersed solid particles from gas phase. These devices have simple construction; are relatively inexpensive to fabricate and operate with moderate pressure losses. Therefore, they are widely used in many engineering processes such as dryers, reactors, advanced coal utilization such as pressurized and circulating fluidized bed combustion and particularly for removal of catalyst from gases in petroleum refinery such as in fluid catalytic cracker (FCC). Despite its simple operation, the fluid dynamics and flow structures in a cyclone separator are very complex. The driving force for particle separation in a cyclone separator is the strong swirling turbulent flow. The gas and the solid particles enter through a tangential inlet at the upper part of the cyclone. The tangential inlet produces a swirling motion of gas, which pushes the particles to the cyclone wall and then both phases swirl down over the cyclone wall. The solid particles leave the cyclone through a duct at the base of the apex of the inverted cone while the gas swirls upward in the middle of the cone and leaves the cyclone from the vortex finder. The swirling motion provides a centrifugal force to the particles while turbulence disperses the particles in the gas phase which increases the possibility of the particle entrainment. Therefore, the performance of a cyclone separator is determined by the turbulence characteristics and particle-particle interaction.Full Tex
Comparative antioxidant activity, total phenol and total flavonoid contents of two Nigerian ocimum species
Antioxidants are compounds which act as a major defense against oxidative stress caused by free radicals. In this study, a comparative evaluation of the antioxidant properties, phenolic and flavonoid contents of the methanolic extracts of Ocimum gratissimum Linn and Ocimum canum Sims was carried out. Crude extracts of both plants were obtained by maceration of powdered plant materials in methanol (80%) for 24hrs. The phenolic and flavonoid contents were determined using standard methods while the antioxidant capacities were evaluated using six different in vitro radical scavenging assays: total antioxidant potential, reductive potential, I, 1-diphenyl-2-picryl-hydrazyl (DPPH) free radical scavenging, lipid peroxidation inhibition, hydroxyl radical and nitric oxide scavenging activity. The total phenolic content in O. gratissimum and O. canum were found to be 32.66 ± 6.21 and 17.19 ± 2.54 mg GAE/g dw while total flavonoid content gave 1.94 ± 0.23 and 0.67 ± 0.01 mg QUE/g dw, respectively. Both extracts had effective reductive potential as well as exhibited strong total antioxidant capacity with increasing concentration of extract. Comparatively, O. gratissimum exhibited a significantly (p < 0.05) higher capacity to quench the DPPH free radical with IC50 value of 26.01 ± 3.2 µg/ml than O. canum, which has an IC50 value of 60.45 ± 5.22 µg/m. O. gratissimum also significantly inhibited membrane lipid peroxidation and hydroxyl radical formation with IC50 of 99.37 ± 8.56 µg/ml and 465.33 ± 21.62 µg/ml, respectively while O. canum correspondingly gave IC50 values of 447.5 ± 35.61 µg/ml and 868.16 ± 43.05 µg/ml. In the nitric oxide scavenging activity, however, O. canum showed a stronger inhibitory effect than O. gratissimum as indicated by their IC50 values of 277.22 ± 15.09 µg/ml and 731 ± 56.99 µg/ml, respectively. These activities are however several folds lower than those of butylated hydroxyl toluene (BHT), ascorbic acid and quercetin used as antioxidant standards. The results demonstrate that O. gratissimum has greater antioxidant capacity than O. canum because of its relatively higher radical scavenging activity in all antiradical tests carried out except the nitric acid scavenging test and higher contents of flavonoid and phenolic compounds. O. gratissimum is therefore more beneficial therapeutically than O. canum since it provides better defense against free radical induced oxidative stress, and this attribute probably explains its relative preference in ethnomedicine for both culinary and medicinal purposes amongst the Ocimum species widely cultivated in South Western Nigeria
Handlungsorientierte Unterrichtsforschung in ökonomischen Kernfächern - am Beispiel des Einsatzes einer arbeitsanalogen Lernaufgabe und eines Planspiels : Action oriented educational research in the fields of economics education
The Alvarado score for predicting acute appendicitis: a systematic review
Background: The Alvarado score can be used to stratify patients with symptoms of suspected appendicitis; the validity of the score in certain patient groups and at different cut points is still unclear. The aim of this study was to assess the discrimination (diagnostic accuracy) and calibration performance of the Alvarado score. Methods: A systematic search of validation studies in Medline, Embase, DARE and The Cochrane library was performed up to April 2011. We assessed the diagnostic accuracy of the score at the two cut-off points: score of 5 (1 to 4 vs. 5 to 10) and score of 7 (1 to 6 vs. 7 to 10). Calibration was analysed across low (1 to 4), intermediate (5 to 6) and high (7 to 10) risk strata. The analysis focused on three sub-groups: men, women and children. Results: Forty-two studies were included in the review. In terms of diagnostic accuracy, the cut-point of 5 was good at 'ruling out' admission for appendicitis (sensitivity 99% overall, 96% men, 99% woman, 99% children). At the cut-point of 7, recommended for 'ruling in' appendicitis and progression to surgery, the score performed poorly in each subgroup (specificity overall 81%, men 57%, woman 73%, children 76%). The Alvarado score is well calibrated in men across all risk strata (low RR 1.06, 95% CI 0.87 to 1.28; intermediate 1.09, 0.86 to 1.37 and high 1.02, 0.97 to 1.08). The score over-predicts the probability of appendicitis in children in the intermediate and high risk groups and in women across all risk strata. Conclusions: The Alvarado score is a useful diagnostic 'rule out' score at a cut point of 5 for all patient groups. The score is well calibrated in men, inconsistent in children and over-predicts the probability of appendicitis in women across all strata of risk
Pseudorapidity dependence of long-range two-particle correlations in pPb collisions at root sNN=5.02 TeV
Peer reviewe
Mapping of potential sea-cage farming sites through spatial modelling: Preliminary operative suggestions to aid sustainable mariculture expansion in India
Sea cage farming in marine open waters is considered as the most viable technique in Indian mariculture to enhance production. Owing to the support of the government in research and development, and policy initiatives, marine cage farming is progressing steadily in the country. Technological guidance from research institutions and financing under the ambitious “Pradhan Mantri Matsya Sampada Yojana (PMMSY)” and blue growth mission objectives have
inspired stakeholders and fisheries administrators in maritime states to explore open sea cage culture. Site selection is a key parameter affecting the success of cage culture systems and, technically analysed geo-referenced demarcation of spatial information is necessary for minimising the risks. Thus, in the light of rising demand for spatial allocation of coastal areas, the present study identifies and aggregates locations within 3 km of the coastline, that have the potential for sea cage farming operations in the country. The site suitability was examined based on optimal standards required for the prospective candidate species selected for mariculture in India. The locations were vectorised in a GIS platform, and the
potential areas available for sea cage installations were demarcated. An optimised site suitability schema was developed for the spatial demarcation of potential site selection.The preliminary results identified 134 sites covering a total area of 46,823.2 ha suitable for marine cage culture along Indian territorial waters. Among the coastal states, the top three states holding the maximum area suitable for sea cage farming are Andhra Pradesh
(11,792 ha), Gujarat (11,572.2 ha) and Tamil Nadu (7,673 ha). It is envisaged that spatial suitability demarcation even on this pilot scale will accelerate the expansion of sea cage farming in the country
Laparoscopy in management of appendicitis in high-, middle-, and low-income countries: a multicenter, prospective, cohort study.
BACKGROUND: Appendicitis is the most common abdominal surgical emergency worldwide. Differences between high- and low-income settings in the availability of laparoscopic appendectomy, alternative management choices, and outcomes are poorly described. The aim was to identify variation in surgical management and outcomes of appendicitis within low-, middle-, and high-Human Development Index (HDI) countries worldwide. METHODS: This is a multicenter, international prospective cohort study. Consecutive sampling of patients undergoing emergency appendectomy over 6 months was conducted. Follow-up lasted 30 days. RESULTS: 4546 patients from 52 countries underwent appendectomy (2499 high-, 1540 middle-, and 507 low-HDI groups). Surgical site infection (SSI) rates were higher in low-HDI (OR 2.57, 95% CI 1.33-4.99, p = 0.005) but not middle-HDI countries (OR 1.38, 95% CI 0.76-2.52, p = 0.291), compared with high-HDI countries after adjustment. A laparoscopic approach was common in high-HDI countries (1693/2499, 67.7%), but infrequent in low-HDI (41/507, 8.1%) and middle-HDI (132/1540, 8.6%) groups. After accounting for case-mix, laparoscopy was still associated with fewer overall complications (OR 0.55, 95% CI 0.42-0.71, p < 0.001) and SSIs (OR 0.22, 95% CI 0.14-0.33, p < 0.001). In propensity-score matched groups within low-/middle-HDI countries, laparoscopy was still associated with fewer overall complications (OR 0.23 95% CI 0.11-0.44) and SSI (OR 0.21 95% CI 0.09-0.45). CONCLUSION: A laparoscopic approach is associated with better outcomes and availability appears to differ by country HDI. Despite the profound clinical, operational, and financial barriers to its widespread introduction, laparoscopy could significantly improve outcomes for patients in low-resource environments. TRIAL REGISTRATION: NCT02179112
Global economic burden of unmet surgical need for appendicitis
Background: There is a substantial gap in provision of adequate surgical care in many low-and middle-income countries. This study aimed to identify the economic burden of unmet surgical need for the common condition of appendicitis. Methods: Data on the incidence of appendicitis from 170 countries and two different approaches were used to estimate numbers of patients who do not receive surgery: as a fixed proportion of the total unmet surgical need per country (approach 1); and based on country income status (approach 2). Indirect costs with current levels of access and local quality, and those if quality were at the standards of high-income countries, were estimated. A human capital approach was applied, focusing on the economic burden resulting from premature death and absenteeism. Results: Excess mortality was 4185 per 100 000 cases of appendicitis using approach 1 and 3448 per 100 000 using approach 2. The economic burden of continuing current levels of access and local quality was US 73 141 million using approach 2. The economic burden of not providing surgical care to the standards of high-income countries was 75 666 million using approach 2. The largest share of these costs resulted from premature death (97.7 per cent) and lack of access (97.0 per cent) in contrast to lack of quality. Conclusion: For a comparatively non-complex emergency condition such as appendicitis, increasing access to care should be prioritized. Although improving quality of care should not be neglected, increasing provision of care at current standards could reduce societal costs substantially
- …