Flame propagation model for the CFR engine under knocking and non-knocking conditions

Includes bibliographical references.Engine knock is one of the factors that limit the design of spark-ignition (SI) engines. It is caused by the auto-ignition of the end-gas during combustion and can lead to severe engine damage and failure. Octane number indicates the ability of a fuel to resist auto-ignition in a SI engine and forms part of the gasoline fuel specification. Burn duration of normal combustion is an important parameter during fuel octane measurement and is often equated to the turbulent flame speed of the fuel. The objective of this project is to develop a combustion model using the turbulent flame propagation concept that can be used to study the influence of the underlying flame speed behaviour during combustion. The model was used to investigate the combustion in the CFR engine (the engine used to measure fuel octane number) since it was found previously that the pressure development, and by implication combustion, differs from that found in production engines

Realization of Woodpile Structure Using Optical Interference Holography

We report the use of a (4+1)-beam optical interference holography technique to fabricate woodpile structures in photo-resists. The configuration consists of 4 linear polarized side beams arranged symmetrically around a circular polarized central beam with all the beams from the same half space, making it easily accessible experimentally. The fabricated woodpile structures are in good agreement with model simulations. Furthermore, woodpiles with the diamond symmetry are also obtained by exploiting the deformations of the photo-resists. Directional bandgaps in the visible range are also observed for the samples with and without the correct stacking of the woodpile structures.Comment: 9 pages and three figure

Measuring the geographic coverage of methadone maintenance programme in Hong Kong by using geographic information system (GIS)

<p>Abstract</p> <p>Objective</p> <p>While access and utilization form core components in assessing the effectiveness of a health service, the concept of coverage is often neglected. In this study we propose to develop a GIS-based methodological framework for the measurement of district-based geographic coverage to examine the service effectiveness of methadone treatment programme (MTP) in Hong Kong on a regular basis.</p> <p>Methods</p> <p>To overcome the incompatibility of spatial units, population data and data of heroin addiction of the year 2001 are interpolated by population-weighted and area-weighted algorithms. Standard overlay and proximity analytical functions are used to delineate altogether 20 accessible zones around each methadone clinic at a fixed 1.5 km Euclidean distance. Geographic coverage here is defined as the percentage of heroin addicts covered by a methadone clinic within the accessible zone by district.</p> <p>Results</p> <p>A total of 6413 out of 11000 reported heroin addicts are found geographically covered. The average geographic coverage in Hong Kong is 44.6%, with the figure varying from 0% to 96% by district. One district having no clinic results in 0% coverage whereas another without a clinic yields 15.3% coverage from the clinic in adjacent district. Maps illustrating district-based geographic coverage are generated.</p> <p>Conclusion</p> <p>As continuous data collection is required for a monitoring system, the simplified approach facilitates the handling of large volume data and relevant data analysis. It is concluded that the number of methadone clinics is as important as their locations. Geographic coverage could become an important consideration for monitoring harm reduction.</p

THE EFFECTIVENESS OF RECIPROCAL TEACHING AS READING COMPREHENSION INTERVENTION: A SYSTEMATIC REVIEW

Background and Purpose: This paper presents a comprehensive review of the research on reading comprehension interventions for ESL learners. Although numerous reviews have reported the effectiveness of reciprocal teaching in improving reading outcomes, only few reviews focused on the use of these strategies in ESL contexts. Hence, this review identified, evaluated and synthesized relevant literature in search of the effectiveness of reciprocal teaching and the features that are associated with improved reading comprehension outcomes. &nbsp; Methodology: Guided by Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA), a thorough search was performed on five major databases using the search terms “reciprocal teaching” or “reciprocal reading” and “reading comprehension” or “text comprehension”. &nbsp; Findings: The comprehensive search resulted in a total of 18 articles. The analysis coded these articles&nbsp; into eight main themes with four main themes concentrated on the features of the reciprocal teaching interventions: (a) purposes, (b) learning environment, (c) comprehension-monitoring, and (d) scaffolding, and another four main themes on the outcomes of the interventions: (e) results, (f) comprehension outcome measures, (g) reading strategies, and (h) conceptual change. &nbsp; Contributions: Conclusively, reciprocal teaching fulfilled the key features of effective intervention as significant gains were mostly observed in the research using reciprocal teaching as intervention. The versatility of reciprocal teaching makes the technique adaptable to learners of varying backgrounds, ages and levels of education. &nbsp; Keywords: reciprocal teaching, reading strategies, interventions, ESL learners, comprehension. &nbsp; Cite as: Dew, T. P., Swanto, S., &amp; Pang, V. (2021). The effectiveness of reciprocal teaching as reading comprehension intervention: A systematic review.&nbsp; Journal of Nusantara Studies, 6(2), 156-184. http://dx.doi.org/10.24200/jonus.vol6iss2pp156-18