811 research outputs found

    Justification for the Subject of Congruence and Similarity in the Context of Daily Life and Conceptual Knowledge

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    This study aims to examine prospective elementary mathematics teachers' conceptual knowledge level for congruence and similarity in triangles subject and to examine their ability to represent the knowledge, to associate the knowledge with daily life, and to justify and solve the geometry problems about this subject. The study is designed in a characteristic pattern. Total of 46 prospective elementary mathematics teachers were selected using purposive sampling method. The instruments used to collect data in this study are: GJP (Geometry Justification Problems), GCKQ (Geometry Conceptual Knowledge Questions) and GQDLE (Geometry Questions of Daily Life Examples). The data were analyzed using descriptive statistics method. The results of the study show that 1) the prospective teachers are successful in geometry conceptual knowledge questions but had difficulty in the justification problems; 2) there is a relationship between the theoretical knowledge levels and the argument standards of the prospective teachers; 3) the prospective teachers had difficulty in the daily life examples of congruence and similarity in triangles subject

    Thermal fluctuations on the freeze-out surface of heavy-ion collisions and their impact on particle correlations

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    Particle momentum distributions originating from a quark-gluon plasma asproduced in high-energy nuclear collisions can be influenced by thermalfluctuations in fluid dynamic fields. We study this effect by generalizing thecommonly used kinetic freeze-out prescription by allowing for smallfluctuations around an average in fluid velocity, chemical potentials andtemperature. This leads to the appearance of specific two-body momentumcorrelations. Combining a blast-wave parametrization of the kinetic freeze-outsurface with the thermal correlation functions of an ideal resonance gas, weperform an exploratory study of angular net-charge correlations induced bythermal fluctuations around vanishing chemical potential. We note a diffusionof the near-side peak around Δy=Δϕ=0\Delta y=\Delta\phi=0 induced by variances ofdifferent chemical potentials, which could be investigated experimentally.<br

    Esterase variation in Turkish white-toothed shrews (Crocidura): Record of a trimeric esterase

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    This study focuses on esterase variation of the genus Crocidura in Turkey. A total of 248 white-toothed shrews were analyzed by means of cellulose acetate gel electrophoresis. Liver tissue and alfa naphthyl acetate were used to investigate esterase variation in Turkish white-toothed shrews. A different esterase banding pattern was found in one Crocidura individual. This phenotype had four anodally migrated bands on cellulose acetate gel. The Crocidura individual displaying the given phenotype was identified as Crocidura suaveolens. The different esterase banding pattern observed in this study is considered to be a result of the trimeric structure of esterase in the lesser white-toothed shrew (Crocidura suaveolens)

    Molecular and pomological diversity among pomegranate (Punica granatum L.) cultivars in Eastern Mediterranean region of Turkey

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    Pomegranate (Punica granatum L.) is an important fruit species for Turkey where many cultivars are being cultivated. In this study, we determined the fruit characteristics and RAPD band patterns of sixlocal cultivars from Hatay, Turkey. Our results demonstrated that there is a great level of morphological variation. The principle component analysis of 18 quantitative fruit characteristics revealed that fruitweight, aril number/fruit, peel color and soluble solids/acidity ratio are important traits for discriminating the cultivars tested. The UPGMA cluster of fruit characteristics indicated that ‘Katýrbaý’and ‘Kan narý’ were similar to each other and they were separated from rest of the cultivars. Twenty-two RAPD primers generated total of 106 reproducible bands 22% of which were polymorphic. The UPGMAdendrogram of RAPD data showed that ‘Tatlý nar’ and ‘erife’ were very closely related while ‘ncekabuk’ is distinct from the other cultivars. As a result, discrepancies were detected between morphological and molecular data. Therefore, we confirmed that diversity among the fruitcharacteristics were not good indication of genetic relatedness while molecular tools are valuable to study such similarities

    Acoustic resonances in microfluidic chips: full-image micro-PIV experiments and numerical simulations

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    We show that full-image micro-PIV analysis in combination with images of transient particle motion is a powerful tool for experimental studies of acoustic radiation forces and acoustic streaming in microfluidic chambers under piezo-actuation in the MHz range. The measured steady-state motion of both large 5 um and small 1 um particles can be understood in terms of the acoustic eigenmodes or standing ultra-sound waves in the given experimental microsystems. This interpretation is supported by numerical solutions of the corresponding acoustic wave equation.Comment: RevTex, 10 pages, 9 eps figures; NOTE first authors changed his name to S. Melker Hagsater in the published versio

    Pattern Stability and Trijunction Motion in Eutectic Solidification

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    We demonstrate by both experiments and phase-field simulations that lamellar eutectic growth can be stable for a wide range of spacings below the point of minimum undercooling at low velocity, contrary to what is predicted by existing stability analyses. This overstabilization can be explained by relaxing Cahn's assumption that lamellae grow locally normal to the eutectic interface.Comment: 4 pages, 5 eps figure

    A High Throughput Lab-On-A-Chip System for Label Free Quantification of Breast Cancer Cells under Continuous Flow

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    This paper presents an LOC system combining microfluidic DEP channel with a CMOS image sensor for label and lens free detection and real-time counting of MCF-7 cells under continuous flow. Trapped and then released MCF-7 cells are accurately detected and counted under flow with a CMOS image sensor integrated underneath the DEP channel, for the first time in the literature. CMOS image sensor can capture 391 frames per second (fps) that allows detection of the released cells flowing through the channel with a flow rate up to 130 mu l/min (0.468 m/s). Therefore, the proposed system is able to detect the cells under high flow where conventional techniques for cell quantification such as fluorescent tagging become unusable. Detected cells are automatically counted with a computer program and the counting accuracy of the whole system is 95%. (C) 2016 The Authors. Published by Elsevier Ltd

    Modeling of seawater intrusion in a coastal aquifer of Karaburun Peninsula, western Turkey

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    Seawater intrusion is a major problem to freshwater resources especially in coastal areas where fresh groundwater is surrounded and could be easily influenced by seawater. This study presents the development of a conceptual and numerical model for the coastal aquifer of Karareis region (Karaburun Peninsula) in the western part of Turkey. The study also presents the interpretation and the analysis of the time series data of groundwater levels recorded by data loggers. The SEAWAT model is used in this study to solve the density-dependent flow field and seawater intrusion in the coastal aquifer that is under excessive pumping particularly during summer months. The model was calibrated using the average values of a 1-year dataset and further verified by the average values of another year. Five potential scenarios were analyzed to understand the effects of pumping and climate change on groundwater levels and the extent of seawater intrusion in the next 10 years. The result of the analysis demonstrated high levels of electrical conductivity and chloride along the coastal part of the study area. As a result of the numerical model, seawater intrusion is simulated to move about 420 m toward the land in the next 10 years under “increased pumping” scenario, while a slight change in water level and TDS concentrations was observed in “climate change” scenario. Results also revealed that a reduction in the pumping rate from Karareis wells will be necessary to protect fresh groundwater from contamination by seawater.Scientific and Technological Research Council of Turkey (TUBITAK 113Y042
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