The effects of two different low calcium fly ashes on the hydration of ordinary Portland cement (OPC) pastes containing 50wt.% of fly ash were investigated over a hydration time of 550days. The ...results were compared with a reference blend of OPC containing 50wt.% of inert quartz powder allowing the distinction between "filler effect" and pozzolanic reaction.
Until 2days, no evidence of fly ash reaction was measured and its influence on the hydration is mainly related to the “filler effect”. From 7days on, the effects of the pozzolanic reaction were observed by the consumption of portlandite, the change of the pore solution chemistry, the formation of a presumably water-rich inner hydration product and the change of the C–S–H composition towards higher Al/Si ratio compared to the C–S–H of neat OPC. Additional strength due to the pozzolanic reaction developed after 28days of hydration.
Team Reflexivity and Innovation Schippers, Michaéla C.; West, Michael A.; Dawson, Jeremy F.
Journal of management,
03/2015, Letnik:
41, Številka:
3
Journal Article
Recenzirano
Odprti dostop
Team reflexivity, the extent to which teams collectively reflect upon and adapt their working methods and functioning, has been shown to be an important predictor of team outcomes, notably ...innovation. As described in the current article, the authors developed and tested a team-level contingency model of team reflexivity, work demands, and innovation. They argue that highly reflexive teams will be more innovative than teams low in reflexivity when facing a demanding work environment. A field study of 98 primary health care teams in the United Kingdom corroborated their predictions: Team reflexivity was positively related to team innovation, and team reflexivity and work demands interacted such that high levels of both predicted higher levels of team innovation. Furthermore, an interaction between team reflexivity, quality of physical work environment (PWE), and team innovation showed that poor PWE coupled with high team reflexivity was associated with higher levels of team innovation. These results are discussed in the context of the need for team reflexivity and team innovation among teams at work facing high levels of work demands.
Purpose: This research aims to identify the extent of application of internal auditing standards recognized in Iraqi commercial banks.
Theoretical framework: the Iraqi commercial banks apply ...standards of Attribute for internal auditing issued by professional organizations, and that they apply the performance standards that must be taken into account when carrying out internal auditing work.
Design/methodology/approach: In order to achieve these goals, an exploratory study was conducted according to which (48) questionnaires were distributed, of which (36) questionnaires were returned, and the researchers approved the questionnaire analysis on the SPSS statistical program.
Findings: the result of the research is that Iraqi commercial banks apply internal auditing standards issued by international professional organizations.
Research, Practical & Social implications: The senior management contributes to addressing the remarks of the internal auditor and taking appropriate measures to implement the suggestions and recommendations he makes.
Originality/value: This study measures the effects resulting from adoption the international internal auditing standards in the performance of banking activities after the transition to IFRS in iraqi banks.
The use of silica rich SCMs influences the amount and kind of hydrates formed and thus the volume, the porosity and finally the durability of these materials. At the levels of substitution normally ...used, major changes are the lower Ca/Si ratio in the C–S–H phase and consumption of portlandite. Alumina-rich SCMs increase the Al-uptake in C–S–H and the amounts of aluminate containing hydrates. In general the changes in phase assemblages are well captured by thermodynamic modelling, although better knowledge of the C–S–H is needed.
At early ages, “filler” effects lead to an increased reaction of the clinker phases. Reaction of SCMs starts later and is enhanced with pH and temperature. Composition, fineness and the amount of glassy phase play also an important role. Due to the diverse range of SCM used, generic relations between composition, particle size, exposure conditions as temperature or relative humidity become increasingly crucial.
Background and Study Aim. The motivational aspect of athletes' commitment to training is an important indicator of their sports performance. However, there is insufficient understanding of the subtle ...dynamics that determine this commitment. The purpose of the study is to explore how athletes' motivation relates to their training duration across different sports. It also aims to identify the impact of intrinsic, extrinsic, and amotivation on training hours and to predict athletes' training commitment. Material and Methods. In the study, 60 college students participated. Data collection utilized the Sport Motivation Scale, which assesses three dimensions of motivation: intrinsic, extrinsic, and amotivation. Physical training hours were meticulously recorded by the instructor. A maximum of 14 hours of training was provided per week as part of a training module lasting one complete month. Players who were absent due to illness were excluded from the study. Results. A significant positive correlation was found between intrinsic motivation (r = 0.93) and extrinsic motivation (r = 0.919) with training duration per week (p < 0.01). Additionally, a significant negative correlation was observed between amotivation and training duration per week (r = -0.873, p < 0.01). Motivation accounted for 84.4% of the variance in predicting physical activity training duration. Furthermore, motivation demonstrated a significant positive relationship (β = 0.921) with physical activity training duration. Conclusions. The current research provides evidence that both intrinsic and extrinsic motivation are crucial for engaging athletes in physical training and activity. Furthermore, amotivation serves as a deterrent to good performance in sports. To foster continuous improvement, coaches and instructors must intervene by providing athletes with positive feedback and maintaining their interest in the game through a variety of sports skills.
This paper evaluates the comparative performance of emission and performance standards in a one-stage game of abatement R&D and Cournot duopoly, in terms of R&D propensity, output and social welfare. ...For each standard, firms simultaneously select R&D and output levels, given the standard’s exogenous constraint. A performance standard generates higher R&D investments and output, but lower profit, than the pollution-equivalent emissions standard. The same conclusion extends to social welfare only under high demand. We also conduct a similar comparison for each of the two instruments across the one-stage and the two-stage models. The two-stage model leads to higher levels of R&D and industry output for both standards. The same conclusion applies to the social welfare comparison for the emissions standard. However, for the performance standard, the same conclusion requires a damage parameter below a given threshhold. When the standards are chosen to maximize welfare, the performance comparison becomes highly parameter-dependent, except that social welfare is higher for the performance standard. Some policy implications are discussed.
•The title of the topic was changed to: performance evaluation of nitrogen for fire safety application in aircraft.•Simulation of cup-burner test through CFD.•Reconsider the pool-fire case in ...CFD.•Meaningful discussion and conclusion regarding the observations made during this study.•Additional references were included from RESS journal.
Fire suppression is an important safety certification requirement for aircraft as it is for all safety critical systems. Risk analyses are required at the design and certification stages to determine the probabilities and means of mitigating such risks. Apostolakis et al. (1995) shows an approach for spacecraft, Spyrou and Koromila (2020) for passenger ships and Arshi et al. (2010) for reactors. An important analysis tool for aircraft is the Zonal Analysis process (Chen and Fielding, 2018) Such analyses include investigation of means of fire suppression for which the use of Halon 1301 was a popular choice. The production of Halon and several halocarbons were banned under the Montreal Protocol in 1994, which necessitates an investigation for use of environmental-friendly agents for this application. The primary objective of this paper is to determine the ‘design concentration’11Design concentration is the volumetric concentration of the agent to achieve successful fire suppression in an enclosure. of nitrogen required for fire suppression. Computational Fluid Dynamics (CFD), in combination with experimental verification is described in this paper. The air flow rate in the cup-burner model was varied between 10 L/min and 40 L/min for a low-speed numerical model and was validated against the BS ISO 14520 cup burner test (BS ISO 14520 Annex, 2006) to determine the extinguishing concentration of nitrogen. The study revealed that the design concentration of nitrogen was 34% (14% oxygen concentration). Further investigation suggested that at low air flow rates (10 L/min and 20 L/min case), distortions produced in the flow led to erroneous measurement of oxygen concentration in experiments. The fire suppression model was extended to an n-heptane pool fire in a large enclosure. The recorded design concentration was approximately 39% additional nitrogen corresponding to 13% oxygen concentration by volume. It was observed that the weight of nitrogen required increased by 7.5 times compared to Halon 1301 use for this model. Future work can be explored in aircraft cargo and engine bay fire safety systems through Minimum Performance Standard (MPS) testing and simulations with nitrogen as the agent. Such work will feed directly into system safety assessments during the early design stages, where analyses must precede testing.
There appears to be a mismatch between apparent incompetence in the world and the amount of sociological research it attracts. The aim of this article is to outline a sociology of incompetence and ...justify its value. I begin by defining incompetence as unsatisfactory performance relative to standards. Incompetence is thus intrinsically sociological in being negotiated and socially (re)constituted. The next section foregrounds how widespread and serious incompetence is. This renders effective sociological understanding crucial to welfare. The article then systematically analyses uses of the term in the British Journal of Sociology (a good quality general journal) to assess the current state of research. This analysis fully confirms the neglect of incompetence as a research topic. The next section proposes suitable methods for preliminary incompetence research addressing distinctive challenges like the stigma of being incompetent. These sections then allow incompetence to be better contextualised by other contributing concepts like power, bureaucracy and meritocracy. The final section justifies suggestions about directions for future research.
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