Educational action research in Singapore: To prove or improve?

The rise of educational action research amongst schools in Singapore can be attributed to the government’s belief that educational research and reform can improve school performance and help Singapore keep pace with the impact of globalization. However, against a backdrop of neo-liberal educational reform where efficiency, accountability and demonstrable outcomes are valued, the underlying intent of the action research projects would seem to be inconsistent with the emancipatory intent normally associated with action research. A systematic review was conducted of 71 action research projects submitted to a local educational conference in 2006. Of concern to us is how action research has been narrowly interpreted and recruited simply as an evaluative tool with the emancipatory potential largely ignored. The paper is theoretically framed by governmentality and performativity to explore the embedded power relations that may “fabricate” the action research projects. The findings and discussions suggest a need for the government, schools and teacher-researchers to reflexively question the current expectation of action research and to be clear about its broader purpose

Recent progress on synthesis, multi-scale structure, and properties of Y-Si-O oxides

Yttrium silicates (Y-Si-O oxides), including Y2Si2O7, Y2SiO5, and Y4·67(SiO4)3O apatite, have attracted wide attentions from material scientists and engineers, because of their extensive polymorphisms and important roles as grain boundary phases in improving the high-temperature mechanical/thermal properties of Si3N4and SiC ceramics. Recent interest in these materials has been renewed by their potential applications as high-temperature structural ceramics, oxidation protective coatings, and environmental barrier coatings (EBCs). The salient properties of Y-Si-O oxides are strongly related to their unique chemical bonds and microstructure features. An in-depth understanding on the synthesis - multi-scale structure-property relationships of the Y-Si-O oxides will shine a light on their performance and potential applications. In this review, recent progress of the synthesis, multi-scale structures, and properties of the Y-Si-O oxides are summarised. First, various methods for the synthesis of Y-Si-O ceramics in the forms of powders, bulks, and thin films/coatings are reviewed. Then, the crystal structures, chemical bonds, and atomic microstructures of the polymorphs in the Y-Si-O system are summarised. The third section focuses on the properties of Y-Si-O oxides, involving the mechanical, thermal, dielectric, and tribological properties, their environmental stability, and their structure-property relationships. The outlook for potential applications of Y-Si-O oxides is also highlighted.

Effect of diffusion-layer porosity on the performance of polymer electrolyte fuel cells

The gas-diffusion layer (GDL) influences the performance of electrodes employed with polymer electrolyte fuel cells (PEFCs). A simple and effective method for incorporating a porous structure in the electrode GDL using sucrose as the pore former is reported. Optimal (50 w/o) incorporation of a pore former in the electrode GDL facilitates the access of the gaseous reactants to the catalyst sites and improves the fuel cell performance. Data obtained from permeability and porosity measurements, single-cell performance, and impedance spectroscopy suggest that an optimal porosity helps mitigating mass-polarization losses in the fuel cell resulting in a substantially enhanced performance.

The effect of pressure and W-doping on the properties of ZnO thin films for NO2 gas sensing

Pure and W-doped ZnO thin films were obtained using magnetron sputtering at working pressures of 0.4 Pa and 1.33 Pa. The films were deposited on glass and alumina substrates at room temperature and subsequently annealed at 400oC for 1 hour in air. The effects of pressure and W-doping on the structure, chemical, optical and electronic properties of the ZnO films for gas sensing were examined. From AFM, the doped film deposited at higher pressure (1.33 Pa) has spiky morphology with much lower grain density and porosity compared to the doped film deposited at 0.4 Pa. The average gain size and roughness of the annealed films were estimated to be 65 nm and 2.2 nm, respectively with slightly larger grain size and roughness appeared in the doped films. From XPS the films deposited at 1.33 Pa favored the formation of adsorbed oxygen on the film surface and this has been more pronounced in the doped film which created active sites for OH adsorption. As a consequence the W-doped film deposited at 1.33 Pa was found to have lower oxidation state of W (35.1 eV) than the doped film deposited at 0.4 Pa (35.9 eV). Raman spectra indicated that doping modified the properties of the ZnO film and induced free-carrier defects. The transmittance of the samples also reveals an enhanced free-carrier density in the W-doped films. The refractive index of the pure film was also found to increase from 1.7 to 2.2 after W-doping whereas the optical band gap only slightly increased. The W-doped ZnO film deposited at 0.4 Pa appeared to have favorable properties for enhanced gas sensing. This film showed significantly higher sensing performance towards 5-10 ppm NO2 at lower operating temperature of 150oC most dominantly due to increased free-carrier defects achieved by W-doping.

Phosphorus Partition between Liquid Steel and CaO-SiO2-P2O5-MgO Slag Containing Low FeO

CaO-SiO2-FeOx-P2O5-MgO bearing slags are typical in the basic oxygen steelmaking (BOS) process. The partition ratio of phosphorus between slag and steel is an index of the phosphorus holding capacity of the slag, which determines the phosphorus content achievable in the finished steel. The influences of FeO concentration and basicity on the equilibrium phosphorus partition ratios were experimentally determined at temperatures of 1873 and 1923 K, for conditions of MgO saturation. The partition ratio initially increased with basicity but attained a constant value beyond basicity of 2.5. An increase in FeO concentration up to approximately 13 to 14 mass pet was beneficial for phosphorus partition.

Effects of membrane channel-forming polypeptides on mitochondrial oxidative phosphorylation. A comparison of alamethicin, gramicidin A, melittin and tetraacetyl melittin

Transmembrane channel-forming polypeptides can function as uncouplers of mitochondrial oxidative phosphorylation. The observed effects are dependent on the phosphate ion (Pi) concentration in the medium. At low Pi (2.5 mM) the order of uncoupling efficiencies is gramicidin A much greater than alamethicin greater than tetraacetyl melittin greater than melittin. The remarkably high activity of gramicidin A suggests insertion of preformed channel dimers into the membrane. It is also suggested that lipid phase association of peptides is necessary in the other cases. At Pi = 100 mM inhibitory effects are observed for alamethicin and tetraacetyl melittin. Less pronounced inhibition is seen for melittin, while no such effect is noted for gramicidin A. The site of inhibition is shown to be complex IV, and the differences in the behavior of the peptides are rationalized in terms of channel structures.

Effects of membrane channel-forming polypeptides on mitochondrial oxidative phosphorylation. A comparison of alamethicin, gramicidin A, melittin and tetraacetyl melittin.

Transmembrane channel-forming polypeptides can function as uncouplers of mitochondrial oxidative phosphorylation. The observed effects are dependent on the phosphate ion (Pi) concentration in the medium. At low Pi (2.5 mM) the order of uncoupling efficiencies is gramicidin A much greater than alamethicin greater than tetraacetyl melittin greater than melittin. The remarkably high activity of gramicidin A suggests insertion of preformed channel dimers into the membrane. It is also suggested that lipid phase association of peptides is necessary in the other cases. At Pi = 100 mM inhibitory effects are observed for alamethicin and tetraacetyl melittin. Less pronounced inhibition is seen for melittin, while no such effect is noted for gramicidin A. The site of inhibition is shown to be complex IV, and the differences in the behavior of the peptides are rationalized in terms of channel structures.

Local Politicizations : A Comparison of Finns and French Practicing Democracy

This study examines how do the processes of politicization differ in the Finnish and the French local contexts, and what kinds of consequences do these processes have on the local civic practices, the definitions and redefinitions of democracy and citizenship, the dynamics of power and resistance, and the ways of solving controversies in the public sphere. By means of comparative anthropology of the state , focusing on how democracy actually is practiced in different contexts, politicizations the processes of opening political arenas and recognizing controversy are analyzed. The focus of the study is on local activists engaged in different struggles on various levels of the local public spheres, and local politicians and civil servants participating in these struggles from their respective positions, in two middle-size European cities, Helsinki and Lyon. The empirical analyses of the book compare different political actors and levels of practicing democracy simultaneously. The study is empirically based on four different bodies of material: Ethnographic notes taken during a fieldwork among the activities of several local activist groups; 47 interviews of local activists and politicians; images representing different levels of public portrayals from activist websites (Helsinki N=274, Lyon N=232) and from city information magazines (Helsinki-info N=208, Lyon Citoyen N= 357); and finally, newspaper articles concerning local conflict issues, and reporting on the encounters between local citizens and representatives of the cities (January-June in 2005; Helsingin Sanomat N=96 and Le Progrès N= 102). The study makes three distinctive contributions to the study of current democratic societies: (1) a conceptual one by bringing politicization at the center of a comparison of political cultures, and by considering in parallel the ethnographic group styles theory by Nina Eliasoph and Paul Lichterman, the theory on counter-democracy by Pierre Rosanvallon and the pragmatist justification theory by Luc Boltanski and Laurent Thévenot; (2) an empirical one through the triangulation of ethnographic, thematic interview, visual, and newspaper data through which the different aspects of democratic practices are examined; and (3) a methodological one by developing new ways of analyzing comparative cases an application of Frame Analysis to visual material and the creation of Public Justification Analysis for analyzing morally loaded claims in newspaper reports thus building bridges between cultural, political, and pragmatic sociology. The results of the study indicate that the cultural tools the Finnish civic actors had at their disposal were prone to hinder more than support politicization, whereas the tools the French actors mainly relied on were frequently apt for making politicization possible. This crystallization is defined and detailed in many ways in the analyses of the book. Its consequences to the understanding and future research on the current developments of democracy are multiple, as politicization, while not assuring good results as such, is central to a functioning and vibrant democracy in which injustices can be fixed and new directions and solutions sought collectively.

A combined extended and helical backbone for Boc-(Ala-Leu-Ac(7)c-)(2)-OMe

The structure of the peptide Boc-Ala-Leu-Ac(7)c-Ala-Leu-Ac(7)c-OMe (Ac(7)c,1-aminocycloheptane-1-carboxylic acid) is described in crystals. The presence of two Ac(7)c residues was expected to stabilize a 3(10)-helical fold. Contrary to expectation the structural analysis revealed an unfolded amino terminus, with Ala(1) adopting an extended beta-conformation (phi = -93degrees,psi = 112degrees). Residues 2-5 form a 3(10)-helix, stabilized by three successive intramolecular hydrogen bonds. Notably, two NH groups Ala(1) and Ac(7)c(3) do not form any hydrogen bonds in the crystal. Peptide assembly appears to be dominated by packing of the cycloheptane rings that stack against one another within the molecule and also throughout the crystal in columns.

Designing a blended learning model for primary school language learning

In Finland, there is a desperate need for flexible, reliable and functional multi-e-learning settings for pupils aged 11-13. Southern Finland has several ongoing e-learning projects, but none that develop a multiple setting, with learning and teaching occurring between more than two schools. In 2006, internet connections were not broadband and data transfer was mainly audio data. Connections and technical problems occurred, which were an obstacle to multi-e-learning. Internet connections today enable web-based learning in major parts of
Lapland and by 2015, broadband will reach even the remotest villages up north. Therefore, it is important to research the possibilities of multi-e-learning and to build collaborative, learner-centred, versatile network models for primary school-aged pupils. The resulting model will facilitate distance learning to extend education to rural, sparsely populated areas, and it will give a model of using mobile devices in language portfolios. This will promote regional equality and prevent exclusion. Working with portfolios provides the opportunity to develop mobility from a pedagogical point of view. It is important to study the pros and cons of mobile devices in producing artefacts on portfolios in e-learning and language learning settings.
The current study represents a design-based research approach. The design research approach includes two important aspects concerning the current research: ‘a teacher as researcher’ aspect, which means there is the possibility to be strongly involved in developing processes and an obstacle-aspect, which means that problems while developing, are seen as a
promoter in evolving the designed model, as apposed to negative results.

A new impulse peak voltmeter

The paper describes a simple instrument for the measurement of the peak amplitudes of impulse voltages up to 250 v with an accuracy to ±3%. The response of the instrument is fast enough to read the peak amplitude of a 0.5/10 μsec impulse wave and its response remains the same for impulses of longer duration. Its favourable response has been obtained by charging a capacitor through a thyratron and measuring the voltage across it by an inverted triode voltmeter. The discharge time constant of the instrument is 5000 sec so that the reading can be taken at leisure. It can be used for the measurement of peak amplitudes of repetitive impulse and power frequency voltages also

Studies on pneumatic atomization

A study of atomization has been made with an external mixing-type pneumatic atomizer. The drops were sampled on Vaseline-coated cells using a shutter arrangement and their sizes were measured under a microscope. The effects of liquid viscosity, liquid surface tension, liquid flow rate, air velocity, and nozzle angle on drop size have been studied. A model, which explains adequately the influence of various factors, has been proposed. This model predicts the values of average drop sizes over a wide range of operating conditions. The model also explains the data of other investigators who have used other kinds of pneumatic atomizers.

A new ELISA plate based microtiter well assay for mycobacterial topoisomerase I for the direct screening of enzyme inhibitory monoclonal antibody supernatants

Antigen specific monoclonal antibodies present in crude hybridoma supernatants are normally screened by ELISA on plates coated with the relevant antigen. Screening for inhibitory monoclonals to enzymes would require the evaluation of purified antibodies or antibody containing supernatants for their inhibition of enzyme activity in a separate assay. However, screening for inhibitory antibodies against DNA transacting enzymes such as topoisomerase I (topo I) cannot be done using hybridoma supernatants due to the presence of nucleases in tissue culture media containing foetal calf serum which degrade the DNA substrates upon addition. We have developed a simple and rapid screening procedure for the identification of clones that secrete inhibitory antibodies against mycobacterial topo I using 96 well ELISA microtiter plates. The principle of the method is the selective capture of monoclonal antibodies from crude hybridoma supernatants by topo I that is tethered to the plate through the use of plate-bound polyclonal anti-topo I antibodies. This step allows the nucleases present in the medium to be washed off leaving the inhibitor bound to the tethered enzyme. The inhibitory activity of the captured antibody is assessed by performing an in situ DNA relaxation assay by the addition of supercoiled DNA substrate directly to the microtiter well followed by the analysis of the reaction products by agarose gel electrophoresis. The validity of this method was confirmed by purification of the identified inhibitory antibody and its evaluation in a DNA relaxation assay. Elimination of all enzyme-inhibitory constituents of the culture medium from the well in which the inhibitory antibody is bound to the tethered enzyme may make this method broadly applicable to enzymes such as DNA gyrases, restriction enzymes and other DNA transaction enzymes. Further, the method is simple and avoids the need of prior antibody purification for testing its inhibitory activity. (C) 2010 Elsevier B.V. All rights reserved.

Structure of 5-methyl-2'-deoxycytidine 5'-monophosphate dihydrate

CloHI6N307P.2H20 , Mr = 357.2, triclinic, P1, a = 4-8520 (8), b = 8"3703 (8), c = 10.0199 (12) A, a= 104.578 (9),/3= 102.332 (13), 7=93.670(11) o, V = 381"75 A 3, Z = 1, Dx = 1"55, Dm = 1"53 Mg m -3, a(Cu Ka) = 1.5418 A,/z = 2.01 mm- l, F(000) = 188, T= 290 K, R = 0-049 for 1568 unique reflections.