Developing Mathematical Learning Device Using Ttw (Think- Talk-Write) Strategy Assisted By Learning Cd To Foster Mathematical Communication

This research aims to produce mathematical learning device or tool using TTW strategy that is valid, practical, and effective. The developed device consists of syllabi, Learning Implementation Plan (RPP), Student Reading which is packaged in CD (BBS), and an evaluation tool. Receiver of treatment or Subjects are the eighth grade students of Muhammadiyah Junior High School in Purworejo. First experiment held in the class A of eighth grade students aimed to determine the legibility of device and the level of difficulty, distinguishing features, and reliability test learning outcomes. Second experiment conducted in class C of eighth grade students aimed to verify the practicality of the device and the effectiveness of learning using developed devices, whereas the class G is as control class. Results from 5 validations of the device are: the mean score of syllabi is 3.48; RPP is 3.79; BBS is 3.73; LKS is 3.73; assessment tool is 3.71 (on scale 1-4). Such results mean that validation criteria of the device is valid. The score of experiment results showed that the criteria of learning process is 3.80; the students’ response is 93.85%; the teacher’s score is 3.91, that means it’s a practical device. Learning using the devices results a classical learning mastery, and achievement test of an experimental class is better than the control class. Furthermore, student’s activity has a positive influence for achievement, so it’s the effective device. Key words: developed device, Think-Talk-Write (TTW), the mathematical learnin

Engineering model test plan. Space storable propellant module environmental control technology

Test program for engineering model of thermal control system of space storable propellant module in simulated environment

The Search for AGN in Distant Galaxy Clusters

We are undertaking the first systematic study of the prevalence of AGN activity in a large sample of high redshift galaxy clusters. Local clusters contain mainly red elliptical galaxies, and have little or no luminous AGN activity. However, recent studies of some moderate to high redshift clusters have revealed significant numbers of luminous AGN within the cluster. This effect may parallel the Butcher-Oemler effect - the increase in the fraction of blue galaxies in distant clusters compared to local clusters. Our aim is to verify and quantify recent evidence that AGN activity in dense environments increases with redshift, and to evaluate the significance of this effect. As cluster AGN are far less prevalent than field sources, a large sample of over 120 cluster fields at z > 0.1 has been selected from the Chandra archives and is being analysed for excess point sources. The size of the excess, the radial distribution and flux of the sources and the dependence of these on cluster redshift and luminosity will reveal important information about the triggering and fueling of AGN.Comment: 2 pages, to appear in proceedings of 'Multi-wavelength AGN surveys', Cozumel, 200

Semileptonic decays of heavy baryons in the relativistic quark model

Semileptonic decays of heavy baryons consisting of one heavy (Q=b,c) and two light (q=u,d,s) quarks are considered in the heavy-quark--light-diquark approximation. The relativistic quasipotential equation is used for obtaining masses and wave functions of both diquarks and baryons within the constituent quark model. The weak transition matrix elements are expressed through the overlap integrals of the baryon wave functions. The Isgur-Wise functions are determined in the whole accessible kinematic range. The exclusive semileptonic decay rates and different asymmetries are calculated with applying the heavy quark 1/m_Q expansion. The evaluated Lambda_b -> Lambda_c l nu decay rate agrees with its experimental value.Comment: 22 pages, 9 figure

Rare BsB_s decays in the relativistic quark model

The branchings fractions of the rare $B_s$ decays are calculated in the framework of the QCD-motivated relativistic quark model. The form factors of the weak $B_s$ transitions to light mesons are expressed through the overlap integral of the initial and final meson wave functions in the whole accessible kinematical range. Explicit determination of the momentum transfer dependence of the form factors without additional model assumptions and extrapolations significantly improve the reliability of the obtained results. The approximate analytical form of the form factors is given in order to simplify the comparison with other predictions and experiment. The calculated form factors are applied for the investigations of the rare semileptonic, radiative and nonleptonic $B_s$ decays. The factorization approximation is used for the description of the nonleptonic decays. All results agree well with available experimental data.Comment: 23 pages, 10 figure