Prediction of the flow inside a micro gas turbine combustor

The main purpose of this study is to predict the flow dynamics inside a micro gas turbine combustor model. The flow field inside the combustor is controlled by the liner shape and size, wall side holes shape, size and arrangement (primary, secondary and dilution holes), and primary air swirler configuration. Air swirler adds sufficient swirling to the inlet flow to generate central recirculation region (CRZ) which is necessary for flame stability and fuel air mixing enhancement. Therefore designing an appropriate air swirler is a challenge to produce stable, efficient and low emission combustion with low pressure losses. Four axial flat vane swirlers with 20 °, 30 °, 45 ° and 60 ° vane angle corresponding to swirl number of 0.27, 0.42, 0.74, and 1.285 respectively were used in this analysis to show vane angle effect on the internal flow field. The flow behavior was investigated numerically using CFD solver FLUENT 6.2. This study has provided physical insight into the flow pattern inside the combustion chamber. Results show that the swirling action is augmented with the increase in the vane angle, which leads to increase in the turbulence strength, recirculation zone size, and amount of recirculated mass. However, all these happen at the expense of the increase in pressure losses. In case of 20 ° swirler (swirl number < 0.4), the produced swirling flow is not enough to generate CRZ

The VI Nav cards: a holistic approach to supporting the design of navigation aids for the blind and visually impaired

The Royal National Institute for Blind People (RNIB) estimates that there are around two million Blind and Visually Impaired (B/VI) people in the UK. Due primarily to the general ageing of the population, this number is expected to increase to four million by 2050. Previous research has highlighted that B/VI people frequently experience problems with their mobility and thus desire improved means for travel and navigation. As a consequence, researchers and industry put much effort into producing a range of navigation aids. Nevertheless, there is considerable evidence that such supporting mechanisms typically fail to satisfy the wide range of needs that B/VI people have for their aids, and thus tend to have low adoption rates. The aim of this thesis is to curate the various needs that B/VI people have for their navigation aids, and package this design knowledge into a novel set of ideation cards that can be used to better support B/VI navigation aid design. The principal benefit of using ideation cards over other methods of democratising academic design knowledge, such as design guidelines, is the utility of ideation cards in creative design sessions. The intention is that, by using ideation cards, designers will be better positioned to consider at the point of design the wide range of needs that B/VI people have for their navigation aids and thus be better equipped to produce navigation aids that satisfy the full scope of needs. Although ideation cards may be developed by following a participatory design methodology, this research does not take such an approach. To collect the needs, I conducted in-depth interviews with nine B/VI people and two employees of Wayfindr, a leading navigation aid design consultancy based in London. The cards were created following Golembewski and Selby's (2010) five-step method for creating ideation decks. The cards were then evaluated in a set of trial studies with seven human factors researchers, three executives of the Guide Dogs charity in the UK , and a VI person. All data was analysed using Braun and Clarke's (2012) Thematic Analysis method. My thesis makes fives main contributions. Firstly, my research contributes a set of ideation cards , known as the VI Nav cards, that can be used to design and evaluate navigation aids to support the needs of B/VI people. The intention is that these cards can be used to embed a holistic consideration of the needs of B/VI people into future navigation aid design efforts. Secondly, while the literature typically only discusses the challenges that B/VI people face `outdoors' and `indoors', there is little discussion of the types of challenges that occur in specific environments, e.g. Train Stations, Shopping Centres, Airports. An understanding of this is important, as different types of locations under these general headings are far from homogeneous. I outline the navigation challenges that can occur in specific environments mentioned by my participants. Thirdly, although there is much discussion in the literature about the needs that B/VI people may have for their navigation aids, there is little, if any, discussion of the barriers that can prevent an aid from becoming successful commercially. Understanding these requirements is important if navigation aids are to go on to have a significant impact on the B/VI community and I present and discuss the important commercial factors from the perspectives of B/VI users and of industry. Fourthly, ideation cards are typically only presented as methods of generating ideas. Because of the incorporation of an evaluation element in my cards, I demonstrate how ideation cards can be used more widely to evaluate pre-existing ideas, even those of third-parties. This is very useful for organisations such as Guide Dogs or the RNIB who may wish to check for common issues before making recommendations of tools to their service users. Finally, this thesis defines how ideation cards, and their usage, can be made accessible to B/VI people. This is important not only for the cards in this thesis, but also for the wider HCI design community, as they continue to strive to make their practises and methods participatory and accessible to all

Talent management and sustainable performance in travel agents: do green intellectual capital and green servant leadership matter?

Talent management (TM) can contribute to improving sustainable business performance in the face of a competitive and socially responsible environment. The use of TM to improve tourism staff skills and motivation is contentious, given such jobs are seen as routine and low-paid. Indeed, the precise processes through which TM techniques support sustained performance outcomes in tourism enterprises requires examination. This paper provides empirical evidence for the impact of TM practices on sustainable organizational performance (SOP). This effect of TM on performance is mediated by green intellectual capital (GIC). The moderating role of green servant leadership (GSL) on the link between GIC and SOP is also examined. PLS-SEM was employed to analyze 327 responses collected from travel agencies employees in Egypt. The results reveal that as expected, TM practices have significant effects on GIC, which in turn significantly impacts SOP. The mediating role of GIC on the relationship between TM practices (apart from talent retention) and SOP is supported. However, the moderating role of GSL is not confirmed. These results demonstrate the importance of an inclusive approach to developing staff, leading to intellectual capital and improved organizational sustainability. The study highlights the importance of strategic workforce planning and succession management

Evaluation of Antiproliferative Activity of Some Traditional Anticancer Herbal Remedies from Jordan

Purpose: To evaluate the in vitro antiproliferative activity of the extracts of the three plants against a panel of human tumor cell lines representing the most common types of cancer in Jordan, viz, breast and colorectal and skin cancers.Methods: The methanol extracts of the aerial parts of the three plants (Arbutus andrachne L., Chrysanthemum coronarium L., and Teucrium polium L.) were prepared and assessed for antiproliferative activity against six human tumor cell lines (A375.S2, WM1361A, CACO-2, HRT18, MCF-7, T47D) using 3-(4,5-dimethylthiazol-2-yl)-2,5 diphenyltetrazolium bromide MTT cell proliferation assay.Results: C. coronarium extract, at the concentration range of 25 to 400 μg/mL, significantly inhibited (10 – 50 %) the proliferation of the 6 cell lines in a dose-dependent manner, whilst the extracts of the other two plants exhibited weak antiproliferative activity (2 – 10 % inhibition). The half-maximal inhibitory concentration (IC50) values of C. coronarium extract against the six cell lines were in the range of 75.8 to 138.5 μg/mL.Conclusion: The methanol extract of the aerial parts C. coronarium possesses a relatively potent antiproliferative activity and therefore might be a potential source of natural compounds that can be developed into new antineoplastic agents.Keywords: Antiproliferative, Arbutus andrachne L., Chrysanthemum coronarium L., Teucrium polium L. Jordan flora, Medicinal plants, Cancer, Antineoplasti

The critical level of vitamin D in childhood asthma

Objectives: Studies have suggested a significant link between vitamin D status and asthma. We sought to determine the cutoff level of25 hydroxy (25-OH) vitamin D that is significantly linked to asthma status in children.Methods: Our cross-sectional study comprised 90 asthmatic children, aged 2-18 years. They were evaluated clinically and classified according to asthma severity and control. Asthma control test (ACT) was performed in those aged above 4 years.Pulmonary functions were performed in cooperative children (n=59). Serum 25-OH vitamin D levels were measured by ELISA in all patients.Results: The study comprised 52 boys (57.7%) and 38 girls (42.3%) with mean age 7.03±4.36 years. Thirty-six patients (40%) had mild asthma, 37 (41%) moderate asthma and 17 (19%) had severe asthma. Forty-two patients (46.6%) had controlled asthma; 14 (15.6%) partially controlled and 34 (37.8%) had uncontrolled asthma. ACT score ranged: 11-26, with mean score: 18.9 ± 4.3 SD. Serum 25-OHvitamin D levels ranged between 2-48 ng/ml (mean± SD: 12.2 ± 9 ng/ml); levels were comparable among different grades of asthma severity (f= 1.975, p=0.145), while the uncontrolled asthma group showed the lowest levels (f=8.511, p &lt;0.001). 25-OH vitamin D levels correlated positively with ACT score (r= 0.369, p= &lt;0.001) but not with inhaled steroids doses or any of the pulmonary function parameters. A level of 7.5 ng/ml was associated with partial/completeuncontrol of asthma with 81 % sensitivity and 53 % specificity.Conclusion: 25-OH vitamin D levels below 7.5 ng/ml are associated with poor asthma status in children.Keywords: Asthma, allergy, children, severity, inhaled steroids, 25 hydroxy vitamin D

Design and Fabrication a W-Shape Form Dual-Band Flexible Antenna For Biomedical Applications

This study suggests a dual band flexible antenna for use at 900 and 2450 MHz. With a footprint of 0.23 o, 0.120 o, and 0.0007 o, where o is the lowest resonance wavelength, the antenna is relatively tiny. The antenna is built from a straightforward geometrical structure consisting of a W-shaped serpentine structure supplied by a microstrip line and a partial ground plane utilizing the Defected Ground Structure (DGS) technology in order to achieve wide operational bandwidth. In order to boost resonance, an additional capacitor was inserted between the slots, creating a portable dual-band antenna. Several performance metrics\u27 findings and the ones that had been measured were compared. The antenna\u27s potential for rigid and flexible electronics is increased by its good size, bandwidth, gain, and radiation pattern

A vision to strengthen resources and capacity of the Palestinian health research system: a qualitative assessment

The World Health Organization has proposed a global strategy to build a robust Health Research System Resources and Infrastructural Capacity (HRSRIC). Despite the growing research productivity, HRSRIC in Palestine has rarely been investigated.; To analyse perceptions of health research system performers to understand the status of HRSRIC, identify its gaps, and propose policy solutions to strengthen HRSRIC.; This qualitative study targeted 3 health sectors: government, academia, and local and international organizations. Fifty-two in-depth interviews and 6 focus group discussions were conducted with key informants who were selected purposively. Data were analysed using MAXQDA 12.; Despite the availability of competent personnel, the overall HRSRIC, such as human and financial resources, and facilities, forms a central challenge. HR financing is limited, unsustainable, and flows from external and individual sources. The public and private funds are largely in shortage with resources misallocation and donors' conditionality. HR quality is moderate while knowledge transfer and translation are not well conceptualized and inappropriately performed. Lack of governance, coordination, HRSRIC strategy, resource allocation, systematic and reliable data, evidence-informed culture, and environmental impacts are the main common gaps.; The overall status of HRSRIC in Palestine is still lacking and major challenges persist where the pace of strengthening efforts is steady. There is an emphasis that strengthening HRSRIC is an imperative step and real investment opportunity for building a successful health research system. Political commitment, consolidated leadership structure, operational capacity building strengthening strategy, resources mobilization, and sovereignty are key requirements