242 resultados para ALI


Relevância:

10.00% 10.00%

Publicador:

Resumo:

Educational reforms currently being enacted in Kuwaiti Family and Consumer Sciences (FCS) in response to contemporary demands for increased student-centred teaching and learning are challenging for FCS teachers due to their limited experience with student-centred learning tools such as Graphic Organisers (GOs). To adopt these reforms, Kuwaiti teachers require a better understanding of and competency in promoting cognitive learning processes that will maximise student-centred learning approaches. This study followed the experiences of four Grade 6 FCS Kuwaiti teachers as they undertook a Professional Development (PD) program specifically designed to advance their understanding of the use of GOs and then as they implemented what they had learned in their Grade 6 FCS classroom. The PD program developed for this study was informed by Nasseh.s competency PD model as well as Piaget and Ausubel.s cognitive theories. This model enabled an assessment and evaluation of the development of the teachers. competencies as an outcome of the PD program in terms of the adoption of GOs, in particular, and their capacity to use GOs to engage students in personalised, in-depth, learning through critical thinking and understanding. The research revealed that the PD program was influential in reforming the teachers. learning, understanding of and competency in, cognitive and visual theories of learning, so that they facilitated student-centred teaching and learning processes that enabled students to adopt and adapt GOs in constructivist learning. The implementation of five GOs - Flow Chart, Concept Maps, K-W-L Chart, Fishbone Diagram and Venn Diagram - as learning tools in classrooms was investigated to find if changes in pedagogical approach for supporting conceptual learning through cognitive information processing would reduce the cognitive work load of students and produce better learning approaches. The study as evidenced by the participant teachers. responses and classroom observations, showed a marked increase in student interest, participation, critical thought, problem solving skills, as a result of using GOs, compared to using traditional teaching and learning methods. A theoretical model was developed from the study based on the premise that teachers. knowledge of the subject, pedagogy and student learning precede the implementation of student-centred learning reform, that it plays an important role in the implementation of student-centred learning and that it brings about a change in teaching practice. The model affirmed that observed change in teaching-practice included aspects of teachers. beliefs, as well as confidence and effect on workplace and on student learning, including engagement, understanding, critical thinking and problem solving. The model assumed that change in teaching practice is inseparable from teachers. lifelong PD needs related to knowledge, understanding, skills and competency. These findings produced a set of preliminary guidelines for establishing student-centred constructivist strategies in Kuwaiti education while retaining Kuwait.s cultural uniqueness.

Relevância:

10.00% 10.00%

Publicador:

Relevância:

10.00% 10.00%

Publicador:

Resumo:

While social enterprises have gained increasing policy attention as vehicles for generating innovative responses to complex social and environmental problems, surprisingly little is known about them. In particular, the social innovation produced by social enterprises (Mulgan, Tucker, Ali, & Sander, 2007) has been presumed rather than demonstrated, and remains under-investigated in the literature. While social enterprises are held to be inherently innovative as they seek to response to social needs (Nicholls, 2010), there has been conjecture that the collaborative governance arrangements typical in social enterprises may be conducive to innovation (Lumpkin, Moss, Gras, Kato, & Amezcua, In press), as members and volunteers provide a source of creative ideas and are unfettered in such thinking by responsibility to deliver organisational outcomes (Hendry, 2004). However this is complicated by the sheer array of governance arrangements which exist in social enterprises, which range from flat participatory democratic structures through to hierarchical arrangements. In continental Europe, there has been a stronger focus on democratic participation as a characteristic of Social Enterprises than, for example, the USA. In response to this gap in knowledge, a research project was undertaken to identify the population of social enterprises in Australia. The size, composition and the social innovations initiated by these enterprises has been reported elsewhere (see Barraket, 2010). The purpose of this paper is to undertake a closer examination of innovation in social enterprises – particularly how the collaborative governance of social enterprises might influence innovation. Given the pre-paradigmatic state of social entrepreneurship research (Nicholls, 2010), and the importance of drawing draw on established theories in order to advance theory (Short, Moss, & Lumpkin, 2009), a number of conceptual steps are needed in order to examine how collaborative governance might influence by social enterprises. In this paper, we commence by advancing a definition as to what a social enterprise is. In light of our focus on the potential role of collaborative governance in social innovation amongst social enterprises, we go on to consider the collaborative forms of governance prevalent in the Third Sector. Then, collaborative innovation is explored. Drawing on this information and our research data, we finally consider how collaborative governance might affect innovation amongst social enterprises.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Generally, the magnitude of pollutant emissions from diesel engines is ultimately coupled to the structure of fuel molecules. The presence of oxygen, level of unsaturation and the carbon chain length of respective molecules influence the combustion chemistry. It is speculated that increased oxygen content in the fuel may lead to the increased oxidative potential (Stevanovic, S. 2013). Also, upon the exposure to UV and ozone in the atmosphere, the chemical composition of the exhaust is changed. The presence of an oxidant and UV is triggering the cascade of photochemical reactions as well as the partitioning of semi-volatile compounds between the gas and particle phase. To gain an insight into the relationship between the molecular structures of the esters, their volatile organic content and the potential toxicity of diesel exhaust particulate matter, measurements were conducted on a modern common rail diesel engine. This research also investigates the contribution of atmospheric conditions on the transfer of semi-volatile fraction of diesel exhaust from the gas phase to the particle phase and the extent to which semi-volatile compounds (SVOCs) are related to the oxidative potential, expressed through the concentration of reactive oxygen species (ROS) (Stevanovic, S. 2013)...

Relevância:

10.00% 10.00%

Publicador:

Resumo:

The issue of particle emissions from diesel engines is still a matter of concern due its deleterious effects both on human health and environment(Ristovski et al., 2012). Recently, International Agency for Research on Cancer (IARC) inclusion of diesel engine exhaust particles as carcinogenic to human health added a new margin on it. Apart from the use of after treatment technology, biodiesel is also considered as potential way to reduce particle emission alongside with other emissions(Xue, Grift, & Hansen, 2011). Global biodiesel production is still reasonably small compared to its counterpart fossil diesel, but even this small amount comes from a wide variety of feed stocks. Contrary to fossil diesel, the important physicochemical properties of biodiesel vary among different feed stocks(Hoekman, Broch, Robbins, Ceniceros, & Natarajan, 2012).

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Introduction: Apoptosis is the final destiny of many cells in the body, though this process has been observed in some pathological processes. One of these pathological processes is femoral head non-traumatic osteonecrosis. Among many pro/anti-apoptotic factors, nitric oxide has recently been an area of further interest. Osteocyte apoptosis and its relation to pro-apoptotic action invite further research, and the inducible form of nitric oxide synthase (iNOS)—which produces a high concentration of nitric oxide—has been flagged. The aim of this study was to investigate the effect of hyperbaric oxygen (HBO) and inducible NOS suppressor (Aminoguanidine) in prevention of femoral head osteonecrosis in an experimental model of osteonecrosis in spontaneous hypertensive rats (SHRs). Methods: After animal ethic approval 34 SHR rats were divided into four groups. Ten rats were allocated to the control group without any treatment, and eight rats were allocated to three treatment groups namely: HBO, Aminoguanidine (AMG), and the combination of HBO and AMG treatments (HBO+AMG). The HBO group received 250 kPa of oxygen via hyperbaric chamber for 30 days started at their 5th week of life; the AMG group received 1mg/ml of AMG in drinking water from the fifth week till the 17th week of life; and the last group received a combination of these treatments. Rats were sacrificed at the end of the 17th week of life and both femurs were analysed for evidence of osteonecrosis using Micro CT scan and H&E staining. Also, osteocyte apoptosis and the presence of two different forms of NOS (inducible (iNOS) and endothelial (eNOS)) were analysed by immunostaining and apoptosis staining (Hoechst and TUNEL). Results: Bone morphology of metaphyseal and epiphyseal area of all rats were investigated and analysed. Micro CT findings revealed significantly higher mean fractional trabecular bone volume (FBV) of metaphyseal area in untreated SHRs compared with all other treatments (HBO, P<0.05, HBO+AMG, P<0.005, and AMG P<0.001). Bone surface to volume ratio also significantly increased with HBO+AMG and AMG treatments when compared with the control group (18.7 Vs 20.8, P<0.05, and 18.7 Vs 21.1, P<0.05). Epiphyseal mean FBV did not change significantly among groups. In the metaphyseal area, trabecular thickness and numbers significantly decreased with AMG treatment, while trabecular separation significantly increased with both AMG and HBO+AMG treatment. Histological ratio of no ossification and osteonecrosis was 37.5%, 43.7%, 18.7% and 6.2% of control, HBO, HBO+AMG and AMG groups respectively with only significant difference observed between HBO and AMG treatment (P<0.01). High concentration of iNOS was observed in the region of osteonecrosis while there was no evidence of eNOS activity around that region. In comparison with the control group, the ratio of osteocyte apoptosis significantly reduced in AMG treatment (P<0.005). We also observed significantly fewer apoptotic osteocytes in AMG group comparing with HBO treatment (P<0.05). Conclusion: None of our treatments prevents osteonecrosis at the histological or micro CT scan level. High concentration of iNOS in the region of osteonecrosis and significant reduction of osteocyte apoptosis with AMG treatment were supportive of iNOS modulating osteocyte apoptosis in SHRs.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

The inconsistent findings of past board diversity research demand a test of competing linear and curvilinear diversity–performance predictions. This research focuses on board age and gender diversity, and presents a positive linear prediction based on resource dependence theory, a negative linear prediction based on social identity theory, and an inverted U-shaped curvilinear prediction based on the integration of resource dependence theory with social identity theory. The predictions were tested using archival data on 288 large organizations listed on the Australian Securities Exchange, with a 1-year time lag between diversity (age and gender) and performance (employee productivity and return on assets). The results indicate a positive linear relationship between gender diversity and employee productivity, a negative linear relationship between age diversity and return on assets, and an inverted U-shaped curvilinear relationship between age diversity and return on assets. The findings provide additional evidence on the business case for board gender diversity and refine the business case for board age diversity.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

3D virtual reality, including the current generation of multi-user virtual worlds, has had a long history of use in education and training, and it experienced a surge of renewed interest with the advent of Second Life in 2003. What followed shortly after were several years marked by considerable hype around the use of virtual worlds for teaching, learning and research in higher education. For the moment, uptake of the technology seems to have plateaued, with academics either maintaining the status quo and continuing to use virtual worlds as they have previously done or choosing to opt out altogether. This paper presents a brief review of the use of virtual worlds in the Australian and New Zealand higher education sector in the past and reports on its use in the sector at the present time, based on input from members of the Australian and New Zealand Virtual Worlds Working Group. It then adopts a forward-looking perspective amid the current climate of uncertainty, musing on future directions and offering suggestions for potential new applications in light of recent technological developments and innovations in the area.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

A5/1 is a shift register based stream cipher which provides privacy for the GSM system. In this paper, we analyse the loading of the secret key and IV during the initialisation process of A5/1. We demonstrate the existence of weak key-IV pairs in the A5/1 cipher due to this loading process; these weak key-IV pairs may generate one, two or three registers containing all-zero values, which may lead in turn to weak keystream sequences. In the case where two or three registers contain only zeros, we describe a distinguisher which leads to a complete decryption of the affected messages.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

The formation of highly anisotropic AuPt alloys has been achieved via a simple electrochemical approach without the need for organic surfactants to direct the growth process. The surface and bulk properties of these materials were characterised by scanning electron microscopy (SEM), X-ray diffraction (XRD), energy dispersive X-ray spectroscopy (EDX) and electrochemically by cyclic voltammetry to confirm alloy formation. It was found that AuPt materials are highly active for both the model hydrogen evolution reaction and the fuel cell relevant formic acid oxidation reaction. In particular for the latter case the preferred dehydrogenation pathway was observed at AuPt compared to nanostructured Pt prepared under identical electrochemical conditions which demonstrated the less preferred dehydration pathway. The enhanced performance is attributed to both the ensemble effect which facilitates CO(ads) removal from the surface as well as the highly anisotropic nanostructure of AuPt.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Because of increased competition between healthcare providers, higher customer expectations, stringent checks on insurance payments and new government regulations, it has become vital for healthcare organisations to enhance the quality of the care they provide, to increase efficiency, and to improve the cost effectiveness of their services. Consequently, a number of quality management concepts and tools are employed in the healthcare domain to achieve the most efficient ways of using time, manpower, space and other resources. Emergency departments are designed to provide a high-quality medical service with immediate availability of resources to those in need of emergency care. The challenge of maintaining a smooth flow of patients in emergency departments is a global problem. This study attempts to improve the patient flow in emergency departments by considering Lean techniques and Six Sigma methodology in a comprehensive conceptual framework. The proposed research will develop a systematic approach through integration of Lean techniques with Six Sigma methodology to improve patient flow in emergency departments. The results reported in this paper are based on a standard questionnaire survey of 350 patients in the Emergency Department of Aseer Central Hospital in Saudi Arabia. The results of the study led us to determine the most significant variables affecting patient satisfaction with patient flow, including waiting time during patient treatment in the emergency department; effectiveness of the system when dealing with the patient’s complaints; and the layout of the emergency department. The proposed model will be developed within a performance evaluation metric based on these critical variables, to be evaluated in future work within fuzzy logic for continuous quality improvement.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Non-linear feedback shift register (NLFSR) ciphers are cryptographic tools of choice of the industry especially for mobile communication. Their attractive feature is a high efficiency when implemented in hardware or software. However, the main problem of NLFSR ciphers is that their security is still not well investigated. The paper makes a progress in the study of the security of NLFSR ciphers. In particular, we show a distinguishing attack on linearly filtered NLFSR (or LF-NLFSR) ciphers. We extend the attack to a linear combination of LF-NLFSRs. We investigate the security of a modified version of the Grain stream cipher and show its vulnerability to both key recovery and distinguishing attacks.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Most civil engineering structures are formed using a number of materials that are bonded to each other with their surface-to-surface interaction playing key role on the overall response of the structure. Unfortunately these interactions are extremely variable; simplified and extremely detailed models trialed to date prove quite complex. Models that assume perfect interaction, on the other hand, predict unsafe behavior. In this paper a damage mechanics based interaction between two materials of different softening properties is developed using homogenisation approach. This paper describes the process of developing a bi-material representative volume element (RVE) using damaged homogenisation approach. The novelty in this paper is the development of non-local transient damage identification algorithm. Numerical examples prove the stability of the approach for a simplified RVE and encourage application to other shapes of RVEs.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Stream ciphers are symmetric key cryptosystems that are used commonly to provide confidentiality for a wide range of applications; such as mobile phone, pay TV and Internet data transmissions. This research examines the features and properties of the initialisation processes of existing stream ciphers to identify flaws and weaknesses, then presents recommendations to improve the security of future cipher designs. This research investigates well-known stream ciphers: A5/1, Sfinks and the Common Scrambling Algorithm Stream Cipher (CSA-SC). This research focused on the security of the initialisation process. The recommendations given are based on both the results in the literature and the work in this thesis.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

The ability of poly(acrylic acid) (PAA) with different end groups and molar masses prepared by Atom Transfer Radical Polymerization (ATRP) to inhibit the formation of calcium carbonate scale at low and elevated temperatures was investigated. Inhibition of CaCO3 deposition was affected by the hydrophobicity of the end groups of PAA, with the greatest inhibition seen for PAA with hydrophobic end groups of moderate size (6–10 carbons). The morphologies of CaCO3 crystals were significantly distorted in the presence of these PAAs. The smallest morphological change was in the presence of PAA with long hydrophobic end groups (16 carbons) and the relative inhibition observed for all species were in the same order at 30 °C and 100 °C. As well as distorting morphologies, the scale inhibitors appeared to stabilize the less thermodynamically favorable polymorph, vaterite, to a degree proportional to their ability to inhibit precipitation.