Scaling behavior of a one-dimensional correlated disordered electronic System

A one-dimensional diagonal tight binding electronic system with correlated disorder is investigated. The correlation of the random potential is exponentially decaying with distance and its correlation length diverges as the concentration of "wrong sign" approaches to 1 or 0. The correlated random number sequence can be generated easily with a binary sequence similar to that of a one-dimensional spin glass system. The localization length (LL) and the integrated density of states (IDOS) for long chains are computed. A comparison with numerical results is made with the recently developed scaling technique results. The Coherent Potential Approximation (CPA) is also adopted to obtain scaling functions for both the LL and the IDOS. We confirmed that the scaling functions show a crossover near the band edge and establish their relation to the concentration. For concentrations near to 0 or 1 (longer correlation length case), the scaling behavior is followed only for a very limited range of the potential strengths.Comment: will appear in PR

Anomalous dynamics in two- and three- dimensional Heisenberg-Mattis spin glasses

We investigate the spectral and localization properties of unmagnetized Heisenberg-Mattis spin glasses, in space dimensionalities $d=2$ and 3, at T=0. We use numerical transfer-matrix methods combined with finite-size scaling to calculate Lyapunov exponents, and eigenvalue-counting theorems, coupled with Gaussian elimination algorithms, to evaluate densities of states. In $d=2$ we find that all states are localized, with the localization length diverging as $\omega^{-1}$, as energy $\omega \to 0$. Logarithmic corrections to density of states behave in accordance with theoretical predictions. In $d=3$ the density-of-states dependence on energy is the same as for spin waves in pure antiferromagnets, again in agreement with theoretical predictions, though the corresponding amplitudes differ.Comment: RevTeX4, 9 pages, 9 .eps figure

Examination of Science Achievement in the 8th Grade Level in Turkey in Terms of National and International Exams Depending upon Various Variables

The aim of the present study is to examine the effect of demographic characteristics of students in Turkey upon their performance in TIMSS, an international assessment exam and Secondary Education Transition Examination which is a national exam (OGS). One of the fields of sciences, biology is taken into account as student performance. As a result of the t-test analysis, it was determined that gender has a statistically significant effect on the students’ TIMSS and TEOG exam results; besides, it was found that female students are more successful compared to boys Whether students receive private tutoring which refers to the economic characteristics of the students has not statistically significant effect on TIMSS biology scores, while it has a positive and significant impact upon OGS biology scores.  Moreover, findings revealed that parental educational level has a positive and significant effect on TIMSS and OGS scores of the students. Keywords: TIMSS, TEOG, science achievement, Turkey, private tutorin

Laboratory Assays of Plant Extracts Against Lobesia botrana (Denis & Schiffermüller) (Lepidoptera: Tortricidae) Larvae

[No abstract available

Review of the cedar and oak forest-associated Epuraea latipes species group (Coleoptera: Nitidulidae, Epuraeinae), with description of a new species from southern Turkey

A new species of Epuraea, Epuraea sutcuimamun Avgin, Lason & Audisio sp. n., from southern Turkey (Taurus Chain) was identified using morphological analyses. This species is a member of a circum-Mediterranean endemic group of sap beetles, the Epuraea latipes species group of the Dadopora lineage, which are mostly associated with cedar (Cedrus spp.) forests. Herein, the new species is described, the previously unknown association of the little-known Epuraea subparallela Grouvelle 1896 with meso-xerophilous oaks is reported, and some new records from southern Turkey (Taurus Chain) are listed for the latter species (previously only known from the Nur Mts. in SE Turkey, Osmaniye and Iskenderun provinces). An identification key to species of Dadopora lineage is also provided. Finally, the main palaeogeographic events affecting the Miocene to Holocene dispersal and evolution of species/populations of the Dadopora lineage on cedars and oaks, and the coincident distributional dynamics of Western Palaearctic Cedrus populations throughout the Mediterranean Basin, are discussed