Virtual chemistry laboratory: Effect of constructivist learning environment

The lab applications, which were started to be applied through mid 19th century, not only provide a new point of view but also bring about a new dimension to the lessons. At early times they were used to prove theoretical knowledge but lately they turned into environments where students freely discover knowledge as an individual or in groups. The activities that have come up with the recent form of labs substantially contributed to training ideal students for constructivist approach, who research, inquire, test, seek solutions, wear scientist shoes and deeply reason about the concept of concern. However, on the present stage of our educational system, these activities cannot be included in science lessons for several reasons. At that point virtual labs emerged as an alternative solution for the problems of the instruction in science courses. Thanks to virtual labs presenting different disciplines in a flexible manner, the interaction between the teacher and the learner become 7/24 independent from time and place. This article presents a study that provides insight in the appropriateness of Virtual and real laboratory applications on constructivist learning environment using interactive virtual chemistry laboratory (VCL) development was used in academic year of 2009-2010 for a six week period. The sample of this quasi-experimental study was 90 students from three different 9th grade classrooms of an Anatolian Secondary school in the center of Trabzon city. The student groups were randomly attained as one experimental and two control groups. The data collection tools of the study were; questionnaire of teaching philosophy (QTP), Semi-structured interviews and unstructured observations. The results showed that virtual chemistry laboratory software was just as effective as real chemistry laboratory and it positively affected the facilitating of constructivist learning environment. It was determined that the students in experimental group conducted the experiments as precise as the real ones; they felt themselves safe during the experiments; they could relate the experiments with daily life; they had the opportunity to investigate both macro-molecular and symbolical dimensions of the experiments. It was speculated that using virtual chemistry laboratories as a supportive complement in education will become an indispensable instructional material in terms of both the economy of the nation and the persistency of the learning

Spatial variability of precipitation regimes over Turkey

Turkish annual precipitation regimes are analysed to provide large-scale perspective and redefine precipitation regions. Monthly total precipitation data are employed for 107 stations (1963–2002). Precipitation regime shape (seasonality) and magnitude (size) are classified using a novel multivariate methodology. Six shape and five magnitude classes are identified, which exhibit clear spatial structure. A composite (shape and magnitude) regime classification reveals dominant controls on spatial variability of precipitation. Intra-annual timing and magnitude of precipitation is highly variable due to seasonal shifts in Polar and Subtropical zones and physiographic factors. Nonetheless, the classification methodology is shown to be a powerful tool that identifies physically-interpretable precipitation regions: (1) coastal regimes for Marmara, coastal Aegean, Mediterranean and Black Sea; (2) transitional regimes in continental Aegean and Southeast Anatolia; and (3) inland regimes across central and Eastern Anatolia. This research has practical implications for understanding water resources, which are under ever growing pressure in Turkey

Response of a CMS HGCAL silicon-pad electromagnetic calorimeter prototype to 20-300 GeV positrons

The Compact Muon Solenoid Collaboration is designing a new high-granularity endcap calorimeter, HGCAL, to be installed later this decade. As part of this development work, a prototype system was built, with an electromagnetic section consisting of 14 double-sided structures, providing 28 sampling layers. Each sampling layer has an hexagonal module, where a multipad large-area silicon sensor is glued between an electronics circuit board and a metal baseplate. The sensor pads of approximately 1 cm$^2$ are wire-bonded to the circuit board and are readout by custom integrated circuits. The prototype was extensively tested with beams at CERN's Super Proton Synchrotron in 2018. Based on the data collected with beams of positrons, with energies ranging from 20 to 300 GeV, measurements of the energy resolution and linearity, the position and angular resolutions, and the shower shapes are presented and compared to a detailed Geant4 simulation

Performance of the CMS High Granularity Calorimeter prototype to charged pion beams of 20−-300 GeV/c

The upgrade of the CMS experiment for the high luminosity operation of the LHC comprises the replacement of the current endcap calorimeter by a high granularity sampling calorimeter (HGCAL). The electromagnetic section of the HGCAL is based on silicon sensors interspersed between lead and copper (or copper tungsten) absorbers. The hadronic section uses layers of stainless steel as an absorbing medium and silicon sensors as an active medium in the regions of high radiation exposure, and scintillator tiles directly readout by silicon photomultipliers in the remaining regions. As part of the development of the detector and its readout electronic components, a section of a silicon-based HGCAL prototype detector along with a section of the CALICE AHCAL prototype was exposed to muons, electrons and charged pions in beam test experiments at the H2 beamline at the CERN SPS in October 2018. The AHCAL uses the same technology as foreseen for the HGCAL but with much finer longitudinal segmentation. The performance of the calorimeters in terms of energy response and resolution, longitudinal and transverse shower profiles is studied using negatively charged pions, and is compared to GEANT4 predictions. This is the first report summarizing results of hadronic showers measured by the HGCAL prototype using beam test data.Comment: To be submitted to JINS

Silicon nitride and silicon carbide fabrication using coated powders

Available from British Library Document Supply Centre-DSC:DXN052292 / BLDSC - British Library Document Supply CentreSIGLEGBUnited Kingdo