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An open classroom climate, one where diverse opinions and discussion of social and political issues are welcome, promotes civic development among youth and fosters critical consciousness. Critical ...

This mixed methods study examines the impact of online professional development on preschool teachers’ self-efficacy, burnout, and stress. Participating teachers (n = 89) were randomly assigned int...

Teacher reflection has been at the core of teacher development efforts for almost 100 years, yet inconsistency in the literature results from a lack of clarity on how reflection is conceptualized—from its purpose to processes, and how they relate to refining teacher practice. This article draws from research in cognitive science to explain how engaging in an ongoing reflection approach, focused on observations of real classrooms, can help teachers refine their responses to classroom situations over time. The authors also provide examples of this reflective approach from an online course for early childhood teachers focused on improving teacher–child interactions in the classroom.

The adsorption of methylene blue (MB) on activated carbon fiber (ACF) and granular activated carbon (ACG) was studied in a batch system. The effects of initial concentration, agitation time, solution pH, and temperature were examined. Adsorption isotherms were described using both the Langmuir and Freundlich models. It was found that the Langmuir model fits well with the experimental data. The pseudo-first-order, pseudo-second-order, and intra-particle diffusion models were used to examine the kinetics data. The results obtained showed that empirical kinetics data of both ACF and ACG were only well described by the second-order model. It was observed that the ACF has adsorption performance higher than that of ACG. Adsorption thermodynamics parameters were estimated and their values indicated that the adsorption of MB on ACF and ACG were endothermic and spontaneous processes. Thermodynamic results also indicate that the adsorption of MB on both adsorbents is by chemical interaction.

Adsorption of 4-nitrophenol on palm oil fuel ash activated by amino silane coupling agent was investigated. Experiments were carried out at 30°C as function of contact time, initial concentration (2500–4500 mgl−1) and pH (1–7.4). The equilibrium adsorption data of 4-nitrophenol on activated palm ash were analyzed by Langmuir Freundlich and Temkin models. The results indicated that the Langmuir model provides the best correlation of the experimental data. The maximum adsorption capacity of the activated palm oil fuel ash was determined with the Langmuir equation and found to be 1000 mg g−1 adsorbent at 30oC. Adsorption kinetics data were modeled using the pseudo-first-order, pseudo-second-order and intra-particle diffusion equations. It was shown that pseudo-second-order kinetic equation could best describe the adsorption kinetics. The results obtained in this work indicate that activated palm oil fuel ash is suitable as adsorbent material for adsorption of 4-nitrophenol from aqueous solutions.

This paper presents the directly obtained rotational viscosity values of E7, which includes pentylcyanobiphenol, heptylcyanobiphenol, 4-cyano-4′ -n-octyloxy-1,1′ -biphenyl, and 4-cyano-4′′-n-pentyl-1,1′,1′′-terphenyl, at various temperatures using molecular dynamics computer simulation. The director mean squared displacement was achieved from the squared displacement of the mean director using the concept of the mean director of various nematic liquid crystals. The calculated values were compared with the experiment results that predicted a good agreement. Additional points that must be considered for further study are also discussed.

SYNOPSIS Flat-plate solar collectors are widely used at New Delhi in India for water heating purposes. The roofs of many residential premises in the capital city are fitted with such collectors. This article examines the theoretical aspects of choosing a tilt angle for the solar flat-plate collectors used at New Delhi and makes recommendations on how the collected energy can be increased by varying the tilt angle. In this paper, the collector surface is assumed to be facing South and the calculations are based upon the measured values of hourly global and diffuse solar radiation on a horizontal surface in the capital city. The beam component of the horizontal global radiation is estimated as the difference between the global and diffuse solar radiation. The solar radiation on a tilted surface is calculated as the angle of tilt is varied from 0° to 90°. It is shown that very nearly optimal energy can be collected if the angle of tilt is varied seasonally, four times a year.

This paper targets the issues related to learning and teaching practices for an abstract topic like group theory. It first outlines our choice in focusing on this topic and then explains the importance of tools like concept maps applied in such abstract topics. This research explains how students and instructors can benefit from using this tool. Different examples from our interactive sessions with students are quoted to identify the state of mind of students and the challenges that they face. Group theory, being abstract in nature, with no applied aspect, and involving a blend of definitions, axioms, theorems and their proofs, poses severe problems of learning in this field. Students are often helpless while tackling a problem, unable to utilise any problem solving strategy and troubled by haphazard links among prior knowledge structures. Our experimentation methodology is discussed in detail and the results obtained are shared in this paper. In addition, we have demonstrated discovery-based lear...

A new relationship for estimating the sediment removal efficiency of vortex chamber type sediment extractor is developed using the data from literature. The procedure for design of vortex chamber extractor is listed and illustrated through examples. Data from laboratories and field have been analysed for validation of the existing relationships on its sediment removal efficiency.

A highly sensitive enzyme immunoassay is described for the detection of atrazine residues in water. Atrazine derivative was conjugated to Bovine Serum Albumin (BSA) to obtain an immunizing antigen and to Horseradish Peroxidase enzyme (POD) to obtain a marker for immunoassay. The formation of these conjugations was confirmed by UV spectroscopy as well as by gel-electrophoresis. Polyclonal antibodies were raised in rabbits by immunization with an atrazine-BSA conjugate containing 29 atrazine residues per BSA molecule. An ELISA on microtitration plates was optimized with peroxidase-atrazine conjugate. The middle of the test (50% B/Bo) was found to be at 90 ng/l, which is well below the maximum concentration permitted by the EC guidelines for drinking water. Detection limits for atrazine of about 1 ng/l could be reached. The assay did not require concentration or cleanup steps for drinking or ground water samples. Validation experiments showed good accuracy and precision. No cross-reactivities were shown by other s-triazines like terbutryn, ametryn, terbuthylazine, des-isopropylatrazine, and de-ethylatrazine except hydroxyatrazine. The latter was present at very low levels that can be calibrated/standardized before analysis or it may be considered as leftover residues of atrazine. Based on these results, it is suggested that this test can be applied to obtain fairly accurate results for atrazine concentration in water samples from different sources.

This paper introduces a modified staircase method for optimizing the cutter path for face milling convex polygonal surfaces. The strategy for optimal face milling of flat triangular polygons is explained. Analytical equations have been developed to calculate individual segments along the cutter path leading to a comprehensive equation for calculating the total cutter path. The method does not require an iterative approach to calculate the length of cutter path and produces better results when compared with other published methods using a similar illustrative example. The findings indicate that the optimal path is likely to be obtained when the number of stairs is minimum which happens when the stairs are generated parallel to the largest edge. However, it appears unlikely that a single equation is possible that will give the global optimum path. In conclusion, the strategy developed can also be used for finding optimum cutter path for n -sided polygonal surfaces.

Advanced part programming languages like APT have the facility for stating pocket milling operations with one or more statements. However, these statements apply only to convex pockets. In this paper, an algorithm for machining non-convex pockets is described. This is done by defining one suitable edge of the polygon as a reference line and then defining a series of cutter paths parallel to it resulting in a continuous cutter path. The paper also describes the procedure for selecting reference line and cutter locations, the calculations involved and the computerization of the algorithm. Finally, it gives an illustrated example of a cutter path generated for a hypothetical component.

This paper reports the results of illumination levels at 76 factories in the industrial estate of Jeddah in Saudi Arabia. The factories were selected at random from different types of industries such as plastic, metal, chemical industries etc. Subsequent analysis of the data was carried out to obtain global picture about the illumination practices at the factories. The survey reveals existence of over illumination during day shifts inmost of the factories. This is due to use of natural light and also, due to use of excessive artificial lights, on occasions. There is, as well, under illumination at night shifts in significant number of factories which indicate design insufficiency and poor maintenance. There is also very wide variation in illumination levels amongst factories indicating lack of any standard practice.

The essential oil obtained from Mentha longifolia plants growing wild in Jordan has been analyzed by GC and GC/MS. The main consituent has been isolated and identified as piperitenone oxide (83.7%).

This paper reports the detailed field study carried out to asses the noise stresses in Jeddah Industrial Estate in Saudi Arabia. The study was carried out over a period of two years and covered a total of 78 factories producing food, chemical, plastic, metal, paper and other types of products. A global analysis is provided to obtain a clear picture of the magnitude of the noise stresses prevailing in the area. The report is concluded with some suggestions to improve the situation.

Heat stress assessment in the work place is of vital importance for the well‐being of industrial workers and consequently the optimum performance of the industrial facilities. A methodology for determining the heat stress in a large number of factories is presented. The Wet Bulb Globe Temperature (WBGT) index was adapted in this study. Detailed strategy is given for proper and efficient assessment. The data were carefully analyzed in the light of set international standards and the degree of compliance of the facilities surveyed. Furthermore other factors such as the type of industry, air‐conditioning and outdoor conditions which affect the indoor situation, were also investiated.

Boca Raton, CRC Press, 2012, 567 pp., £82.00 (hardback), ISBN 978-1439873120. The study of compound semiconductors comprises a wide range of materials, which are found in a crystallised format such...

Neutron Physics for Nuclear Reactors: Unpublished Writings by Enrico Fermi, edited by S. Esposito and O. Pisanti, Singapore, World Scientific Publishing, 2010, 704 pp., 230 illustrations and 23 tab...

High Energy Radiation from Black Holes: Gamma Rays, Cosmic Rays, and Neutrinos, by Charles D. Dermer and Govind Menon, Princeton University Press, 2009, 568 pp., US$ 75.00 (paperback), ISBN 978‐0‐6...

An Introduction to the Physics of Particle Accelerators, by Mario Conte and William W. MacKay, Singapore, World Scientific Publishing, 2008, 374 pp., 116 illus., $108 (hardback), ISBN 978-981-277-9...

Nuclear Medicine Physics, Series in Medical Physics and Biomedical Engineering, edited by J.J. De Lima, Abingdon, CRC Press, 2010, 524 pp., £95.00 (hardback), ISBN 978-1-58-488795-9. Scope: monogra...

Fundamentals of Nuclear Models: Foundational Models, by David J. Rowe and John L. Wood, Singapore, World Scientific Publisher Press, 2010, 676 pp., $75.00 (paperback), ISBN 978-981-256-955-4. Scope...

Modern Atomic and Nuclear Physics (Revised Edition): Problems and Solutions Manual, by Fujia Yang and Joseph H. Hamilton, Singapore, World Scientific, 2010, 104 pp., 9 Illust. and 3 tables, £13.00 ...

Nuclear Reactions for Astrophysics: Principles, Calculation and Applications of Low-Energy Reactions, by Ian J. Thompson and Filomena M. Nunes, Cambridge, Cambridge University Press, 2009, 480 pp.,...

SUMMARY Academic advising, which plays a crucial role in higher education, is often ignored and not given its due importance. This paper is an attempt to make up for this attitude. It proposes a complete system for academic advising taking into account its' multifarious aspects. In the process, the paper draws heavily on the author's experience of organising academic advising in the College of Engineering, King Abdul-Aziz University, Jeddah, Saudi Arabia.

The extraction of Eu(III) has been carried out from a 1 M (H,Na)Clo4 solution into different organic solvents at constant total concentration (6.67 × 10−3 M) of the extractant, di-n-butyl-ethane-(l,2)-diphosphonic acid (H2B2-EDP). The distribution coefficient of Eu(III) is influenced quite appreciably by the nature of the organic solvent. We observe that the distribution coefficient can vary by a factor of 106 for two solvents such as chloroform and ieo-octane. The experimental results are compared with those of Dreze1, who used di-n-butyl-phosphoric acid (HDBP) for the extraction of Eu(lII) into different organic solvents. If we assume that H2-B2-EDP remains monomer for a total concentration of 6.67 × 10−3 M in the solvents used2, then we may conclude that the extraction of Eu(III) by the associated HDBP or the monomer H2B2EDP is influenced in the same manner in the solvents used.