3,850 research outputs found
What is a scientific experiment?: The impact of a professional development course on teachers’ ability to design an inquiry-based science curriculum
Designing inquiry-based science lessons can be a challenge for secondary school teachers. In this study we evaluated the development of in-service teachers’ lesson plans as they took part in a 10-month professional development course in Peru which engaged teachers in the design of inquiry-based lessons. At the beginning, most teachers designed either confirmatory or structured inquiry activities. As the course progressed, however, they started designing guided and open inquiry lesson plans. We found four factors that accounted for this change: re-evaluating the need for lab materials, revising their views on the nature of science, engaging in guided and open inquiry activities themselves, and trying out inquiry-based lessons with their own students. Our results point to the importance of engaging teachers in prolonged and varied opportunities for inquiry as part of teacher education programs in order to achieve the challenge of changing teachers’ views and practices in science education.Fil: PĂ©rez, MarĂa del Carmen B.. Universidad de Piura; PerĂşFil: Furman, Melina Gabriela. Universidad de San AndrĂ©s. Escuela de EducaciĂłn; Argentina. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas; Argentin
Towards a unitary Dalitz plot analysis of three-body hadronic B decays
A unitary model of the final state kaon pion interaction amplitudes in the B
--> K pi pi decays is constructed. The weak decay penguin amplitudes, derived
in QCD factorization, are supplemented by phenomenological contributions. The
strange kaon- pion scalar and vector form factors are used to calculate the
kaon pion effective mass and helicity angle distributions, branching ratios, CP
asymmetries and the phase difference between the B0 and anti B0 decay
amplitudes to K*(892) pi. The fit on the phenomenological parameters leads to a
good agreement with the experimental data, particularly for the
B --> K*(892) pi decays. However, our predicted B+- --> K*0(1430) pi+-,
K*0(1430)--> K+-pi-+ branching fraction is smaller than the results of the
Belle and BaBar collaborations, obtained from isobar model analyses. A new
parameterization of the S-wave kaon- pion effective mass distribution, which
can be used in future experimental Dalitz plot analyses, is proposed.Comment: 5 pages, 1 figure, contribution to Proc. Int. Europhysics Conference
on High Energy Physics (HEP2009), July 16-22, 2009, Krakow, Poland,
PoS(HEP2009)20
Closed loop spray cooling apparatus
A closed loop apparatus for spraying coolant against the back of a radiation target is described. The coolant was circulated through a closed loop with a bubble of inert gas being maintained around the spray. Mesh material was disposed between the bubble and the surface of the liquid coolant which was below the bubble at a predetermined level. In a second embodiment, no inert gas was used, the bubble consisting of a vapor produced when the coolant was sprayed against the target
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